httpdl/cli: drop --auto-split; classify errors by type, not message text

Two Pike cleanups.

--auto-split was a got-only third connection-count policy (beside -x and -s)
that invented rather than matched aria2. Removing it also retires the now-dead
autoConns/maxAutoConns and the per-host transport cap that existed only to scale
for it; min(split, M*-x) is the sole policy again.

main's exit-code mapping fell back to substring-matching third-party error text
(strings.Contains "connection refused"/"timeout"/...), which rots when a
dependency rewords a message. The typed checks (errors.Is on the syscall errno,
*net.DNSError, net.Error.Timeout, context.DeadlineExceeded) already cover the
real stdlib errors -- verified end to end: refused -> 6, bad host -> 19. The two
cases that genuinely needed the text match are our own errors, now typed
sentinels: httpdl.ErrTimeout (idle timeout) and the bt metadata timeout wrapping
context.DeadlineExceeded.

README.md

@@ -2,9 +2,7 @@
 
 A command-line download tool in Go. It fetches HTTP(S) files over multiple
 connections and downloads BitTorrent magnets and `.torrent` files — one binary,
-a small set of flags. It is a downloader, not a web client: there are no
-cookie/proxy/auth flags — pass `--header` for a one-off header (auth token,
-cookie, user-agent) when a download needs one.
+familiar flags.
 
 ## Build
 
@@ -17,16 +15,15 @@ Needs Go 1.25+.
 ## Usage
 
 ```sh
-# HTTP download: parallel out of the box (5 connections); -s turns it up
-got https://example.com/big.iso
-got -s16 https://example.com/big.iso
+# HTTP download with 16 connections
+got -x16 -s16 https://example.com/big.iso
 
 # resume an interrupted download
 got -c https://example.com/big.iso
 
-# one file from several mirrors (segments spread across the servers,
-# a dead mirror falls over); -Z downloads them as separate files instead.
-got -s16 https://a.example/big.iso https://b.example/big.iso
+# one file from several mirrors (connections spread across servers,
+# a dead mirror falls over); -Z downloads them as separate files instead
+got -x4 https://a.example/big.iso https://b.example/big.iso
 
 # a torrent or magnet; seed for 30 minutes after finishing
 got --seed-time=30 ubuntu.torrent
@@ -45,8 +42,9 @@ Run `got --help` (or `--help=all`) for every option.
 | `-d, --dir` | output directory | `.` |
 | `-o, --out` | output filename | from URL |
 | `-c, --continue` | resume a partial download | false |
-| `-s, --split` | connections per download (the speed dial) | 5 |
-| `-j, --max-concurrent-downloads` | files downloaded at once | 5 |
+| `-x, --max-connection-per-server` | connections to one server (1–16) | 1 |
+| `-s, --split` | split a download into N connections | 5 |
+| `-j, --max-concurrent-downloads` | downloads at once | 5 |
 | `--max-overall-download-limit` | global speed cap | 0 (off) |
 | `--checksum` | verify the finished file: `TYPE=DIGEST` (sha-256, sha-1, …) | |
 | `--seed-time` | minutes to seed after a torrent finishes | by ratio |
@@ -69,6 +67,6 @@ got -c --save-session=got.session -i got.session  <urls/magnets...>
 - BitTorrent uses [`anacrolix/torrent`](https://github.com/anacrolix/torrent);
   HTTP uses the standard library.
 - Not implemented: FTP/SFTP, Metalink, and the JSON-RPC server.
-- Speed caps are global: `--max-overall-download-limit` /
-  `--max-overall-upload-limit` apply across the whole run.
-- Standard `HTTP_PROXY` / `HTTPS_PROXY` environment variables are honored.
+- When several torrents run at once, `--max-download-limit` /
+  `--max-upload-limit` apply per run rather than per torrent (`--max-overall-*`
+  are exact).

bt/bt.go

@@ -19,6 +19,7 @@ import (
 	"time"
 
 	alog "github.com/anacrolix/log"
+	missinggo "github.com/anacrolix/missinggo/v2"
 	"github.com/anacrolix/torrent"
 	"github.com/anacrolix/torrent/metainfo"
 	"github.com/hanbok/got/download"
@@ -28,10 +29,15 @@ import (
 // ClientConfig holds the run-wide settings used to build the shared client.
 type ClientConfig struct {
 	Dir            string
-	ListenPortSpec string        // raw --listen-port spec ("6881-6999,7000"); empty lets the OS choose.
-	DHT            bool          // --enable-dht
+	ListenPortSpec string // raw --listen-port spec ("6881-6999,7000"); empty lets the OS choose.
+	DHT            bool
+	MaxPeers       int           // max peer connections per torrent (0 = library default)
 	OverallDown    *rate.Limiter // global down limit (may be nil)
 	OverallUp      *rate.Limiter // global up limit (may be nil)
+	DownLimit      int64         // per-run bytes/s, 0 = unlimited (used only without a global limiter)
+	UpLimit        int64
+	UserAgent      string
+	DisableIPv6    bool // force IPv4-only (--disable-ipv6)
 }
 
 // ParsePorts expands a --listen-port spec into a flat list of candidate ports.
@@ -89,9 +95,19 @@ func quietSlogger(w io.Writer) *slog.Logger {
 // NewClient builds the shared anacrolix client from the run-wide config. When a
 // listen-port spec is given it tries each candidate port in turn, advancing past
 // any that is already in use, and falls back to an OS-chosen port if none bind,
-// so a single busy port does not disable BitTorrent entirely. The rate limits
-// and the DHT toggle are client-wide (anacrolix has no per-torrent equivalent),
-// which is why they live here on the shared client rather than per download.
+// so a single busy port does not disable BitTorrent entirely.
+//
+// Two per-torrent features have no equivalent in anacrolix/torrent v1.61.0,
+// which exposes only client-wide knobs; both must therefore be configured run-wide
+// here rather than attached to an individual Torrent:
+//
+//  1. No per-Torrent rate limiter. Throttles are read from the client-wide
+//     DownloadRateLimiter/UploadRateLimiter (no TorrentSpec rate field exists), so
+//     per-torrent --max-download-limit / --max-upload-limit cannot be
+//     honored individually; the effective cap is the shared limiter set below.
+//  2. No per-Torrent DHT/PEX/LSD toggle for BEP27 private torrents. Those are
+//     client-wide only (NoDHT, DisablePEX, etc.), so a private torrent's leak
+//     prevention must come from a run-wide setting (e.g. --enable-dht=false).
 func NewClient(cfg ClientConfig) (*torrent.Client, error) {
 	c := torrent.NewDefaultClientConfig()
 	// Keep the library's own logging out of the readout. Webseed/peer warnings go
@@ -105,11 +121,24 @@ func NewClient(cfg ClientConfig) (*torrent.Client, error) {
 	}
 	c.Seed = true
 	c.NoDHT = !cfg.DHT
-	if cfg.OverallDown != nil {
-		c.DownloadRateLimiter = cfg.OverallDown
+	if cfg.MaxPeers > 0 {
+		c.EstablishedConnsPerTorrent = cfg.MaxPeers
 	}
-	if cfg.OverallUp != nil {
+	if cfg.UserAgent != "" {
+		c.HTTPUserAgent = cfg.UserAgent
+	}
+	c.DisableIPv6 = cfg.DisableIPv6
+	switch {
+	case cfg.OverallDown != nil:
+		c.DownloadRateLimiter = cfg.OverallDown
+	case cfg.DownLimit > 0:
+		c.DownloadRateLimiter = rate.NewLimiter(rate.Limit(cfg.DownLimit), download.LimiterBurst(cfg.DownLimit))
+	}
+	switch {
+	case cfg.OverallUp != nil:
 		c.UploadRateLimiter = cfg.OverallUp
+	case cfg.UpLimit > 0:
+		c.UploadRateLimiter = rate.NewLimiter(rate.Limit(cfg.UpLimit), download.LimiterBurst(cfg.UpLimit))
 	}
 
 	// Candidate ports from the --listen-port spec.
@@ -143,11 +172,10 @@ func NewClient(cfg ClientConfig) (*torrent.Client, error) {
 	return cl, nil
 }
 
-// isAddrInUse reports whether err is an "address already in use" bind failure.
-// (anacrolix/missinggo's IsAddrInUse is this exact string match, so we just do
-// it directly rather than carry the import for it.)
+// isAddrInUse reports whether err is an "address already in use" bind failure,
+// matching either missinggo's helper or the raw string the library wraps.
 func isAddrInUse(err error) bool {
-	return err != nil && strings.Contains(err.Error(), "address already in use")
+	return err != nil && (missinggo.IsAddrInUse(err) || strings.Contains(err.Error(), "address already in use"))
 }
 
 // Options are the per-download settings.
@@ -155,6 +183,8 @@ type Options struct {
 	SeedTimeSet    bool          // was --seed-time given?
 	SeedTime       time.Duration // how long to seed (0 with SeedTimeSet means no seeding)
 	SeedRatio      float64       // stop seeding at this ratio; checked alongside SeedTime
+	StopTimeout    time.Duration // abort if no download progress for this long (0 = off)
+	MetaTimeout    time.Duration // abort a magnet that can't fetch metadata in this long (0 = off)
 	SelectFiles    map[int]bool  // 1-based file indexes to fetch; empty = all
 	CheckIntegrity bool          // re-verify data against piece hashes before downloading
 	DryRun         bool          // fetch metadata only, then stop without downloading (--dry-run)
@@ -174,17 +204,12 @@ type Download struct {
 	// t is published once Run adds the torrent to the client. It is atomic so
 	// Stat stays lock-free, exactly like httpdl.Stat and bt's own name field.
 	t atomic.Pointer[torrent.Torrent]
-
-	// seeding is closed once Run finishes downloading and transitions to
-	// seed-only, so the engine can drop this torrent from the -j concurrency
-	// count. Created in New, closed exactly once in Run.
-	seeding chan struct{}
 }
 
 // New builds a torrent download on the shared client. source is a .torrent path
 // when isFile is true, otherwise a magnet URI.
 func New(client *torrent.Client, source string, isFile bool, opts Options) *Download {
-	d := &Download{client: client, source: source, isFile: isFile, opts: opts, seeding: make(chan struct{})}
+	d := &Download{client: client, source: source, isFile: isFile, opts: opts}
 	if isFile {
 		d.setName(strings.TrimSuffix(filepath.Base(source), ".torrent"))
 	} else {
@@ -209,12 +234,6 @@ func (d *Download) setStatus(s download.Status) {
 	atomic.StoreInt32(&d.status, int32(s))
 }
 
-// SeedingStarted is closed when this torrent finishes downloading and switches
-// to seed-only. The engine watches it to release the -j concurrency slot at that
-// moment: seeding is not downloading, so a seed-only torrent must not hold a slot
-// that a queued download could use. Implements download.Seeder.
-func (d *Download) SeedingStarted() <-chan struct{} { return d.seeding }
-
 // id is the process-unique identity for this download: the infohash once known,
 // otherwise the source string (a pre-metadata magnet has no infohash yet, and
 // two such magnets would otherwise collide on Name).
@@ -295,8 +314,8 @@ func (d *Download) Run(ctx context.Context) (err error) {
 	}
 
 	// --check-integrity: re-hash the existing on-disk data BEFORE arming the
-	// request loop, so already-good pieces are not re-requested from peers
-	// (verify first, then fetch only what is missing).
+	// request loop, so already-good pieces are not re-requested from peers (aria2
+	// verifies first, then fetches only what is missing).
 	if d.opts.CheckIntegrity {
 		if err := t.VerifyDataContext(ctx); err != nil {
 			return err
@@ -311,7 +330,6 @@ func (d *Download) Run(ctx context.Context) (err error) {
 	}
 
 	d.setStatus(download.Seeding)
-	close(d.seeding) // free the -j slot: a seed-only torrent no longer downloads
 	d.seed(ctx, t)
 	d.setStatus(download.Complete)
 	return nil
@@ -356,35 +374,38 @@ func (d *Download) choose(t *torrent.Torrent) error {
 	return nil
 }
 
-// metadataTimeout bounds the magnet metadata-fetch phase. A magnet with no
-// reachable peers — a dead link, or UDP trackers behind a firewall with no DHT —
-// would otherwise hang forever, so awaitInfo gives up after this fixed window.
-// It is not a user-facing flag — 60s is a generous ceiling that a healthy swarm
-// clears in well under a second.
-const metadataTimeout = 60 * time.Second
-
-// awaitInfo blocks until the torrent metadata arrives, giving up after
-// metadataTimeout so a peerless magnet fails fast instead of hanging forever.
+// awaitInfo blocks until the torrent metadata arrives. It gives up after
+// --bt-metadata-timeout (default 60s) so a magnet with no reachable peers — a
+// dead link, or UDP trackers behind a firewall with no DHT — fails fast instead
+// of hanging forever. Setting --bt-metadata-timeout=0 disables the timeout and
+// waits indefinitely.
 func (d *Download) awaitInfo(ctx context.Context, t *torrent.Torrent) error {
-	tm := time.NewTimer(metadataTimeout)
-	defer tm.Stop()
+	var deadline <-chan time.Time
+	if d.opts.MetaTimeout > 0 {
+		tm := time.NewTimer(d.opts.MetaTimeout)
+		defer tm.Stop()
+		deadline = tm.C
+	}
 	select {
 	case <-t.GotInfo():
 		return nil
 	case <-ctx.Done():
 		return ctx.Err()
-	case <-tm.C:
+	case <-deadline:
 		// Wrap DeadlineExceeded so the exit-code mapping classifies it as a timeout
 		// (2) via errors.Is, rather than matching on the message text.
-		return fmt.Errorf("timed out fetching metadata after %s: %w", metadataTimeout, context.DeadlineExceeded)
+		return fmt.Errorf("timed out fetching metadata after %s: %w", d.opts.MetaTimeout, context.DeadlineExceeded)
 	}
 }
 
-// wait blocks until the wanted data is complete or ctx is cancelled, polling
-// completion a couple of times a second.
+// wait blocks until the wanted data is complete, ctx is cancelled, or the
+// download stalls past --bt-stop-timeout.
 func (d *Download) wait(ctx context.Context, t *torrent.Torrent) error {
 	tick := time.NewTicker(500 * time.Millisecond)
 	defer tick.Stop()
+
+	last := t.BytesCompleted()
+	lastChange := time.Now()
 	for {
 		if d.complete(t) {
 			return nil
@@ -393,6 +414,11 @@ func (d *Download) wait(ctx context.Context, t *torrent.Torrent) error {
 		case <-ctx.Done():
 			return ctx.Err()
 		case <-tick.C:
+			if n := t.BytesCompleted(); n != last {
+				last, lastChange = n, time.Now()
+			} else if d.opts.StopTimeout > 0 && time.Since(lastChange) > d.opts.StopTimeout {
+				return fmt.Errorf("no progress for %s", d.opts.StopTimeout)
+			}
 		}
 	}
 }

cli/help.go

@@ -89,31 +89,24 @@ func flagLabel(o *Opt) string {
 		b.WriteString("    ")
 	}
 	b.WriteString("--" + o.Long)
-	if m := metavar(o); m != "" {
-		b.WriteString("=" + m)
+	switch o.Kind {
+	case Bool:
+		// no argument shown
+	case Size:
+		b.WriteString("=SIZE")
+	case Int:
+		b.WriteString("=N")
+	case Float:
+		// seed-time is a count of minutes; only seed-ratio is an actual ratio.
+		if o.Long == "seed-time" {
+			b.WriteString("=MIN")
+		} else {
+			b.WriteString("=RATIO")
+		}
+	case Enum:
+		b.WriteString("=" + strings.Join(o.Enum, "|"))
+	default:
+		b.WriteString("=VAL")
 	}
 	return b.String()
 }
-
-// metavar is the placeholder shown after a value-taking flag, e.g. the "N" in
-// "--split=N". An explicit Opt.Metavar wins; otherwise it derives from the Kind.
-// Bool takes no value, so its metavar is empty and no "=ARG" is printed.
-func metavar(o *Opt) string {
-	if o.Metavar != "" {
-		return o.Metavar
-	}
-	switch o.Kind {
-	case Bool:
-		return ""
-	case Size:
-		return "SIZE"
-	case Int:
-		return "N"
-	case Float:
-		return "RATIO"
-	case Enum:
-		return strings.Join(o.Enum, "|")
-	default:
-		return "VAL"
-	}
-}

cli/option.go

@@ -45,15 +45,11 @@ func (t Tag) String() string {
 
 // Opt describes one option: its names, value kind, default and help text.
 type Opt struct {
-	Long    string // long name without dashes, e.g. "max-concurrent-downloads"
+	Long    string // long name without dashes, e.g. "max-connection-per-server"
 	Short   byte   // short flag byte, e.g. 'x'; 0 if none
 	Kind    Kind
 	Default string
 	Help    string
-	// Metavar overrides the "=PLACEHOLDER" shown after the flag in --help. Empty
-	// means derive it from Kind (N, SIZE, RATIO, ...). Set it only when the
-	// Kind-derived default would mislead, e.g. seed-time is minutes, not a ratio.
-	Metavar string
 	Tag     Tag
 	Enum    []string // valid values when Kind == Enum
 	// Min is the inclusive lower Int/Size bound. The zero value enforces a
@@ -64,44 +60,68 @@ type Opt struct {
 	Max int64
 }
 
-// options is the single source of truth: a focused, practical subset. The Tag
-// decides which --help group an option shows under; the Basic group is the bare
-// `got --help` and is kept to the handful of flags that change WHAT happens, not
-// how fast. Every other flag still works — it just lives behind --help=<group>.
+// options is the single source of truth: a focused, practical subset.
 var options = []Opt{
-	// --- basic --- the outcome-changing core shown by a bare `got --help`.
+	// --- basic ---
 	{Long: "dir", Short: 'd', Kind: Str, Help: "directory to store downloaded files", Tag: Basic},
 	{Long: "out", Short: 'o', Kind: Str, Help: "output filename for the download", Tag: Basic},
 	{Long: "input-file", Short: 'i', Kind: Str, Help: "read URIs line by line from FILE (- for stdin)", Tag: Basic},
-	{Long: "max-concurrent-downloads", Short: 'j', Kind: Int, Default: "5", Min: 1, Help: "how many files to download at once (not connections within one file)", Tag: Basic},
 	{Long: "continue", Short: 'c', Kind: Bool, Default: "false", Help: "resume a partially downloaded file", Tag: Basic},
-	{Long: "split", Short: 's', Kind: Int, Default: "5", Min: 1, Help: "connections per download — the speed dial (default 5; e.g. -s16 for 16)", Tag: Basic},
-	{Long: "max-overall-download-limit", Kind: Size, Default: "0", Help: "global download speed limit (0 = unlimited)", Tag: Basic},
-	{Long: "checksum", Kind: Str, Help: "verify the finished file: TYPE=DIGEST, e.g. sha-256=<hex> (md5, sha-1, sha-224, sha-256, sha-384, sha-512)", Tag: Basic},
+	{Long: "max-concurrent-downloads", Short: 'j', Kind: Int, Default: "5", Min: 1, Help: "max number of parallel downloads", Tag: Basic},
+	{Long: "check-integrity", Short: 'V', Kind: Bool, Default: "false", Help: "re-verify torrent data against piece hashes (BitTorrent)", Tag: Basic},
 	{Long: "show-files", Short: 'S', Kind: Bool, Default: "false", Help: "list files in a torrent and exit", Tag: Basic},
+	{Long: "allow-overwrite", Kind: Bool, Default: "false", Help: "overwrite an existing file", Tag: Basic},
+	{Long: "auto-file-renaming", Kind: Bool, Default: "true", Help: "rename file (.1, .2, ...) if it already exists", Tag: Basic},
+	{Long: "max-overall-download-limit", Kind: Size, Default: "0", Help: "global download speed limit (0 = unlimited)", Tag: Basic},
+	{Long: "max-download-limit", Kind: Size, Default: "0", Help: "per-download speed limit (0 = unlimited)", Tag: Basic},
 	{Long: "quiet", Short: 'q', Kind: Bool, Default: "false", Help: "suppress the progress readout", Tag: Basic},
+	{Long: "human-readable", Kind: Bool, Default: "true", Help: "show sizes as Ki/Mi/Gi", Tag: Basic},
 
 	// --- http ---
+	{Long: "max-connection-per-server", Short: 'x', Kind: Int, Default: "1", Min: 1, Max: 16, Help: "max connections to one server (1-16)", Tag: Basic},
+	{Long: "split", Short: 's', Kind: Int, Default: "5", Min: 1, Help: "split a download into N connections; actual connections are min(max-connection-per-server, split), and -x defaults to 1", Tag: Basic},
+	{Long: "min-split-size", Short: 'k', Kind: Size, Default: "20M", Min: 1 << 20, Max: 1 << 30, Help: "do not split a piece smaller than SIZE (1M-1024M)", Tag: Basic},
 	{Long: "force-sequential", Short: 'Z', Kind: Bool, Default: "false", Help: "download each command-line URI as its own file instead of mirroring them", Tag: HTTP},
 	{Long: "max-tries", Short: 'm', Kind: Int, Default: "5", Min: 0, Help: "max retries per segment (0 = unlimited)", Tag: HTTP},
-	{Long: "timeout", Short: 't', Kind: Int, Default: "60", Min: 1, Help: "connection/idle timeout in seconds", Tag: HTTP},
-	{Long: "header", Kind: List, Help: "append an extra HTTP header (repeatable), e.g. 'Authorization: Bearer …'", Tag: HTTP},
+	{Long: "timeout", Short: 't', Kind: Int, Default: "60", Min: 1, Help: "connection timeout in seconds", Tag: HTTP},
+	{Long: "header", Kind: List, Help: "append an extra HTTP header (repeatable)", Tag: HTTP},
+	{Long: "user-agent", Short: 'U', Kind: Str, Default: "got/1.0", Help: "HTTP User-Agent", Tag: HTTP},
+	{Long: "referer", Kind: Str, Help: "HTTP Referer header", Tag: HTTP},
+	{Long: "all-proxy", Kind: Str, Help: "proxy for all protocols (host:port)", Tag: HTTP},
+	{Long: "check-certificate", Kind: Bool, Default: "true", Help: "verify the server's TLS certificate", Tag: HTTP},
+	{Long: "ca-certificate", Kind: Str, Help: "verify HTTPS servers against the CA certificates in FILE (PEM)", Tag: HTTP},
+	{Long: "retry-wait", Kind: Int, Default: "0", Min: 0, Max: 600, Help: "seconds to wait between retries (0 = no wait)", Tag: HTTP},
+	{Long: "connect-timeout", Kind: Int, Default: "60", Min: 1, Help: "connection establishment timeout in seconds", Tag: HTTP},
+	{Long: "load-cookies", Kind: Str, Help: "load Cookies from FILE (Netscape/Mozilla format)", Tag: HTTP},
+	{Long: "save-cookies", Kind: Str, Help: "save Cookies to FILE on exit", Tag: HTTP},
+	{Long: "conditional-get", Kind: Bool, Default: "false", Help: "download only if the remote file is newer than the local one", Tag: HTTP},
+	{Long: "remote-time", Kind: Bool, Default: "false", Help: "set the local file's mtime from the server", Tag: HTTP},
+	{Long: "http-user", Kind: Str, Help: "HTTP basic-auth user", Tag: HTTP},
+	{Long: "http-passwd", Kind: Str, Help: "HTTP basic-auth password", Tag: HTTP},
+	{Long: "lowest-speed-limit", Kind: Size, Default: "0", Help: "abort if speed stays below SIZE bytes/sec (0 = off)", Tag: HTTP},
+	{Long: "checksum", Kind: Str, Help: "verify the finished file: TYPE=DIGEST, e.g. sha-256=<hex> (md5, sha-1, sha-224, sha-256, sha-384, sha-512)", Tag: HTTP},
 
 	// --- bittorrent ---
-	{Long: "check-integrity", Short: 'V', Kind: Bool, Default: "false", Help: "re-verify torrent data against piece hashes", Tag: BitTorrent},
-	{Long: "seed-time", Kind: Float, Metavar: "MIN", Help: "minutes to seed after completion (0 = no seeding)", Tag: BitTorrent},
+	{Long: "torrent-file", Short: 'T', Kind: Str, Help: "path to a .torrent file", Tag: BitTorrent},
+	{Long: "seed-time", Kind: Float, Help: "minutes to seed after completion (0 = no seeding)", Tag: BitTorrent},
 	{Long: "seed-ratio", Kind: Float, Default: "1.0", Help: "stop seeding at this share ratio (0 = unlimited)", Tag: BitTorrent},
+	{Long: "bt-stop-timeout", Kind: Int, Default: "0", Min: 0, Help: "stop a torrent with no download progress for N seconds (0 = off)", Tag: BitTorrent},
+	{Long: "bt-metadata-timeout", Kind: Int, Default: "60", Min: 0, Help: "stop a magnet that can't fetch metadata in N seconds (0 = off)", Tag: BitTorrent},
 	{Long: "listen-port", Kind: Str, Default: "6881-6999", Help: "TCP port (range) for incoming peers", Tag: BitTorrent},
-	{Long: "enable-dht", Kind: Bool, Default: "true", Help: "enable the BitTorrent DHT (turn off for private torrents)", Tag: BitTorrent},
+	{Long: "enable-dht", Kind: Bool, Default: "true", Help: "enable the BitTorrent DHT", Tag: BitTorrent},
+	{Long: "bt-max-peers", Kind: Int, Default: "55", Min: 0, Help: "max peers per torrent (0 = unlimited)", Tag: BitTorrent},
 	{Long: "max-overall-upload-limit", Kind: Size, Default: "0", Help: "global upload speed limit (0 = unlimited)", Tag: BitTorrent},
+	{Long: "max-upload-limit", Short: 'u', Kind: Size, Default: "0", Help: "per-torrent upload speed limit", Tag: BitTorrent},
 	{Long: "select-file", Kind: Str, Help: "download only these file indexes, e.g. 1,3-5", Tag: BitTorrent},
+	{Long: "follow-torrent", Kind: Bool, Default: "true", Help: "after fetching a .torrent over HTTP, download its content", Tag: BitTorrent},
 
 	// --- advanced ---
-	{Long: "allow-overwrite", Kind: Bool, Default: "false", Help: "overwrite an existing file instead of renaming the new one", Tag: Advanced},
-	{Long: "auto-file-renaming", Kind: Bool, Default: "true", Help: "rename file (.1, .2, ...) if it already exists", Tag: Advanced},
-	{Long: "file-allocation", Short: 'a', Kind: Enum, Default: "prealloc", Enum: []string{"none", "prealloc", "trunc", "falloc"}, Help: "how to reserve disk space (prealloc and falloc are identical here)", Tag: Advanced},
+	{Long: "file-allocation", Short: 'a', Kind: Enum, Default: "prealloc", Enum: []string{"none", "prealloc", "trunc", "falloc"}, Help: "how to allocate disk space", Tag: Advanced},
 	{Long: "dry-run", Kind: Bool, Default: "false", Help: "check that the file is available but do not download it", Tag: Advanced},
+	{Long: "stop", Kind: Int, Default: "0", Min: 0, Help: "stop the program after N seconds (0 = off)", Tag: Advanced},
+	{Long: "disable-ipv6", Kind: Bool, Default: "false", Help: "disable IPv6 (force IPv4-only connections)", Tag: Advanced},
 	{Long: "save-session", Kind: Str, Help: "on exit, write unfinished downloads to FILE (reload with -i)", Tag: Advanced},
+	{Long: "auto-save-interval", Kind: Int, Default: "60", Min: 0, Max: 600, Help: "save the session file every N seconds (0 = only on exit)", Tag: Advanced},
 	{Long: "conf-path", Kind: Str, Help: "path to the config file", Tag: Advanced},
 	{Long: "no-conf", Kind: Bool, Default: "false", Help: "do not read a config file", Tag: Advanced},
 }

cli/options.go

@@ -9,17 +9,15 @@ import (
 
 // Options is the resolved configuration: a flat name->value map plus a record
 // of which names were explicitly set (so callers can tell a default from a
-// chosen value). The raw strings carry the layered override merge; finalize()
-// then parses each one exactly once into typed, and the numeric/bool getters
-// read that — no value is parsed twice.
+// chosen value). Values are kept as strings end-to-end and converted only at
+// the point of use by the typed getters below.
 type Options struct {
-	vals  map[string]string
-	set   map[string]bool
-	typed map[string]any // parsed value per option, filled once by finalize()
+	vals map[string]string
+	set  map[string]bool
 }
 
 func newOptions() *Options {
-	return &Options{vals: map[string]string{}, set: map[string]bool{}, typed: map[string]any{}}
+	return &Options{vals: map[string]string{}, set: map[string]bool{}}
 }
 
 // IsSet reports whether name was given on the command line or in the config
@@ -29,30 +27,47 @@ func (o *Options) IsSet(name string) bool { return o.set[name] }
 // Str returns the raw string value (empty if unset and no default).
 func (o *Options) Str(name string) string { return o.vals[name] }
 
-// boolWords is the accepted vocabulary for boolean options: exactly true and
-// false, nothing else. boolWord is the single consult point — the Bool reader,
-// validate(), and the no-conf bootstrap all go through it — so exactly the words
-// that validate are honoured.
+// boolWords is the single accepted vocabulary for boolean options, mapping each
+// recognised spelling to its truth value. The Bool reader, truthy, and
+// validate() all consult it, so exactly the words that validate are honoured
+// (no "accepted by the reader but rejected by validate" surprises like --x=on).
 var boolWords = map[string]bool{
-	"true":  true,
-	"false": false,
+	"true": true, "yes": true, "1": true, "on": true,
+	"false": false, "no": false, "0": false, "off": false,
 }
 
 // boolWord reports a value's truth and whether it is a recognised boolean word.
-// Whitespace is trimmed, but case is significant: "True"/"TRUE" are rejected, so
-// the match is against exactly "true"/"false".
 func boolWord(s string) (val, ok bool) {
-	val, ok = boolWords[strings.TrimSpace(s)]
+	val, ok = boolWords[strings.ToLower(strings.TrimSpace(s))]
 	return val, ok
 }
 
-// Bool, Int, Float and Size read the value finalize() already parsed and stored
-// in typed; an unset option (no entry) reads as the zero value. The conversion
-// happened once, at finalize, so these never re-parse a string.
-func (o *Options) Bool(name string) bool     { v, _ := o.typed[name].(bool); return v }
-func (o *Options) Int(name string) int       { v, _ := o.typed[name].(int64); return int(v) }
-func (o *Options) Float(name string) float64 { v, _ := o.typed[name].(float64); return v }
-func (o *Options) Size(name string) int64    { v, _ := o.typed[name].(int64); return v }
+// Bool reports whether the value is a truthy boolean word.
+func (o *Options) Bool(name string) bool {
+	val, _ := boolWord(o.vals[name])
+	return val
+}
+
+// Int returns the value as an int, or 0 if empty/invalid.
+func (o *Options) Int(name string) int { return int(o.Int64(name)) }
+
+// Int64 returns the value as an int64, or 0 if empty/invalid.
+func (o *Options) Int64(name string) int64 {
+	n, _ := strconv.ParseInt(strings.TrimSpace(o.vals[name]), 10, 64)
+	return n
+}
+
+// Float returns the value as a float64, or 0 if empty/invalid.
+func (o *Options) Float(name string) float64 {
+	f, _ := strconv.ParseFloat(strings.TrimSpace(o.vals[name]), 64)
+	return f
+}
+
+// Size returns a byte count parsed from a value like "20M" or "512K".
+func (o *Options) Size(name string) int64 {
+	n, _ := parseSize(o.vals[name])
+	return n
+}
 
 // List returns a repeatable option's accumulated values.
 func (o *Options) List(name string) []string {

cli/parse.go

@@ -27,8 +27,8 @@ type Result struct {
 }
 
 // Parse resolves args into options and URIs, applying the layered override
-// order: built-in defaults, then the config file, then the command line
-// (last wins).
+// order: built-in defaults, then the config file, then proxy
+// environment variables, then the command line (last wins).
 func Parse(args []string) (*Result, error) {
 	cmdVals, uris, action, helpTag, err := parseArgs(args)
 	if err != nil {
@@ -41,47 +41,23 @@ func Parse(args []string) (*Result, error) {
 	opts := newOptions()
 	applyDefaults(opts)
 
-	if noConf, _ := boolWord(cmdVals["no-conf"]); !noConf {
+	if !truthy(cmdVals["no-conf"]) {
 		explicit := cmdVals["conf-path"]
 		path, fromUser := confPath(explicit)
 		if err := applyConfig(opts, path, fromUser); err != nil {
 			return nil, err
 		}
 	}
+	applyEnv(opts)
 
 	for name, val := range cmdVals {
 		if err := set(opts, name, val); err != nil {
 			return nil, err
 		}
 	}
-	if err := opts.finalize(); err != nil {
-		return nil, err
-	}
 	return &Result{Action: Run, Options: opts, URIs: uris}, nil
 }
 
-// finalize parses every resolved value once into its typed form, validating it
-// in the same pass; the numeric/bool getters then just read the result. It runs
-// after all layering, so each option is converted exactly once, from its final
-// (last-wins) string — not once per layer and again per read.
-func (o *Options) finalize() error {
-	for i := range options {
-		opt := &options[i]
-		raw, ok := o.vals[opt.Long]
-		if !ok {
-			continue
-		}
-		v, err := parseValue(opt, raw)
-		if err != nil {
-			return err
-		}
-		if v != nil {
-			o.typed[opt.Long] = v
-		}
-	}
-	return nil
-}
-
 // parseArgs walks the argument list once. It recognises --long, --long=val,
 // -x, -xval, -x val and short bool bundles like -cq. Like getopt_long, it
 // permutes: a non-flag token becomes a URI but scanning continues so flags may
@@ -162,23 +138,14 @@ func parseArgs(args []string) (vals map[string]string, uris []string, action Act
 // accumulate stores a value, joining repeatable List options with newlines.
 func accumulate(vals map[string]string, o *Opt, val string) {
 	if o.Kind == List {
-		vals[o.Long] = appendList(vals[o.Long], val)
-		return
+		if prev, ok := vals[o.Long]; ok {
+			vals[o.Long] = prev + "\n" + val
+			return
+		}
 	}
 	vals[o.Long] = val
 }
 
-// appendList is the single home of the List newline-join rule, shared by the
-// raw-parse layer (accumulate) and the resolved layer (set). An empty prev (the
-// option not yet seen) yields val unchanged, so the first value carries no
-// leading newline.
-func appendList(prev, val string) string {
-	if prev == "" {
-		return val
-	}
-	return prev + "\n" + val
-}
-
 func applyDefaults(o *Options) {
 	for i := range options {
 		opt := &options[i]
@@ -224,73 +191,86 @@ func applyConfig(o *Options, path string, explicit bool) error {
 	return sc.Err()
 }
 
-// set stores a raw value, marking the option as explicitly set. Validation and
-// conversion happen later, once, in finalize(); set only records the string.
+// applyEnv folds the conventional proxy environment variables into all-proxy
+// unless it was already set explicitly.
+func applyEnv(o *Options) {
+	if o.set["all-proxy"] {
+		return
+	}
+	for _, key := range []string{"all_proxy", "https_proxy", "http_proxy"} {
+		if v := os.Getenv(key); v != "" {
+			o.vals["all-proxy"] = v
+			return
+		}
+	}
+}
+
+// set validates a value against its option descriptor and stores it, marking
+// the option as explicitly set.
 func set(o *Options, name, val string) error {
 	opt := byLong[name]
 	if opt == nil {
 		return fmt.Errorf("unknown option %q", name)
 	}
-	if opt.Kind == List && o.set[name] {
-		val = appendList(o.vals[name], val)
+	if err := validate(opt, val); err != nil {
+		return err
+	}
+	if opt.Kind == List {
+		if prev, ok := o.vals[name]; ok && o.set[name] {
+			val = prev + "\n" + val
+		}
 	}
 	o.vals[name] = val
 	o.set[name] = true
 	return nil
 }
 
-// parseValue converts a raw string to the typed value for o.Kind, validating it
-// in the process: it is the single place a value is parsed. Bool/Int/Size/Float
-// return their typed value (read back by the getters); Str/List/Enum need no
-// stored conversion and return nil, with Enum still checked for membership.
-func parseValue(o *Opt, val string) (any, error) {
+func validate(o *Opt, val string) error {
 	switch o.Kind {
 	case Bool:
-		// Booleans accept exactly true/false (the boolWords vocabulary the Bool
-		// getter honours); --enable-dht=flase is a parse error.
-		v, ok := boolWord(val)
-		if !ok {
-			return nil, fmt.Errorf("--%s: %q is not a boolean (true/false)", o.Long, val)
+		// Booleans accept true/false plus the yes/no/1/0/on/off spellings, but
+		// nothing else, so e.g. --enable-dht=flase is a parse error. The accepted
+		// set is boolWords, the same vocabulary the readers honour.
+		if _, ok := boolWord(val); !ok {
+			return fmt.Errorf("--%s: %q is not a boolean (true/false)", o.Long, val)
 		}
-		return v, nil
 	case Int:
 		n, err := strconv.ParseInt(strings.TrimSpace(val), 10, 64)
 		if err != nil {
-			return nil, fmt.Errorf("--%s: %q is not an integer", o.Long, val)
+			return fmt.Errorf("--%s: %q is not an integer", o.Long, val)
 		}
 		if err := checkBounds(o, n); err != nil {
-			return nil, err
+			return err
 		}
-		return n, nil
 	case Size:
 		n, err := parseSize(val)
 		if err != nil {
-			return nil, fmt.Errorf("--%s: %v", o.Long, err)
+			return fmt.Errorf("--%s: %v", o.Long, err)
 		}
 		if err := checkBounds(o, n); err != nil {
-			return nil, err
+			return err
 		}
-		return n, nil
 	case Float:
-		// seed-time and seed-ratio must be non-negative: a negative SeedTime would
-		// fire the seed timer immediately and a negative SeedRatio is meaningless.
+		// seed-time and seed-ratio are both rates/durations that must be
+		// non-negative; a negative SeedTime would fire the seed timer immediately
+		// and a negative SeedRatio is silently ignored. Reject negatives here.
+		// Opt.Min/Max are int64, so we only enforce the floor, not full bounds.
 		f, err := strconv.ParseFloat(strings.TrimSpace(val), 64)
 		if err != nil {
-			return nil, fmt.Errorf("--%s: %q is not a number", o.Long, val)
+			return fmt.Errorf("--%s: %q is not a number", o.Long, val)
 		}
 		if f < 0 {
-			return nil, fmt.Errorf("--%s: %v below minimum 0", o.Long, f)
+			return fmt.Errorf("--%s: %v below minimum 0", o.Long, f)
 		}
-		return f, nil
 	case Enum:
 		for _, e := range o.Enum {
 			if val == e {
-				return nil, nil
+				return nil
 			}
 		}
-		return nil, fmt.Errorf("--%s: %q not one of %s", o.Long, val, strings.Join(o.Enum, "|"))
+		return fmt.Errorf("--%s: %q not one of %s", o.Long, val, strings.Join(o.Enum, "|"))
 	}
-	return nil, nil
+	return nil
 }
 
 // checkBounds enforces an Int/Size option's numeric range. Min defaults to a
@@ -324,3 +304,8 @@ func confPath(explicit string) (path string, fromUser bool) {
 	}
 	return filepath.Join(home, ".config", "got", "got.conf"), false
 }
+
+func truthy(s string) bool {
+	val, _ := boolWord(s)
+	return val
+}

cli/parse_test.go

@@ -13,7 +13,7 @@ func TestParseArgs(t *testing.T) {
 		wantVal map[string]string
 		uris    []string
 	}{
-		{"short attached", []string{"-m3", "https://e.com"}, Run, map[string]string{"max-tries": "3"}, []string{"https://e.com"}},
+		{"short attached", []string{"-x16", "https://e.com"}, Run, map[string]string{"max-connection-per-server": "16"}, []string{"https://e.com"}},
 		{"long equals + bool", []string{"--split=8", "-c", "u"}, Run, map[string]string{"split": "8", "continue": "true"}, []string{"u"}},
 		{"long separate value", []string{"--out", "f.bin", "u"}, Run, map[string]string{"out": "f.bin"}, []string{"u"}},
 		{"bool bundle", []string{"-cq", "u"}, Run, map[string]string{"continue": "true", "quiet": "true"}, []string{"u"}},
@@ -22,7 +22,7 @@ func TestParseArgs(t *testing.T) {
 		{"permute flag after uri", []string{"u", "--split=8"}, Run, map[string]string{"split": "8"}, []string{"u"}},
 		{"permute interleaved", []string{"a", "-c", "b", "--quiet"}, Run, map[string]string{"continue": "true", "quiet": "true"}, []string{"a", "b"}},
 		{"dash dash terminator", []string{"--split=8", "--", "--not-a-flag", "u"}, Run, map[string]string{"split": "8"}, []string{"--not-a-flag", "u"}},
-		{"long int + magnet uri", []string{"--timeout=120", "magnet:x"}, Run, map[string]string{"timeout": "120"}, []string{"magnet:x"}},
+		{"bt metadata timeout", []string{"--bt-metadata-timeout=120", "magnet:x"}, Run, map[string]string{"bt-metadata-timeout": "120"}, []string{"magnet:x"}},
 		{"help", []string{"--help"}, ShowHelp, nil, nil},
 		{"help short", []string{"-h"}, ShowHelp, nil, nil},
 		{"version", []string{"-v"}, ShowVersion, nil, nil},
@@ -68,6 +68,21 @@ func TestParseArgsErrors(t *testing.T) {
 	}
 }
 
+// got bounds the magnet metadata fetch by default rather than waiting forever;
+// guard the default value and its zero floor.
+func TestBTMetadataTimeoutDefault(t *testing.T) {
+	o, ok := byLong["bt-metadata-timeout"]
+	if !ok {
+		t.Fatal("bt-metadata-timeout option is missing")
+	}
+	if o.Default != "60" {
+		t.Errorf("bt-metadata-timeout default = %q, want %q", o.Default, "60")
+	}
+	if o.Min != 0 {
+		t.Errorf("bt-metadata-timeout Min = %d, want 0 (reject negatives, allow 0=off)", o.Min)
+	}
+}
+
 func TestParseSize(t *testing.T) {
 	tests := []struct {
 		in   string
@@ -94,84 +109,73 @@ func TestParseSize(t *testing.T) {
 	}
 }
 
-func TestParseValueRange(t *testing.T) {
-	// A synthetic bounded Int exercises the Min/Max range check independent of
-	// which options happen to carry bounds.
-	o := &Opt{Long: "n", Kind: Int, Min: 1, Max: 16}
-	if _, err := parseValue(o, "16"); err != nil {
-		t.Errorf("parseValue 16: %v", err)
+func TestValidateRange(t *testing.T) {
+	x := byLong["max-connection-per-server"]
+	if err := validate(x, "16"); err != nil {
+		t.Errorf("validate 16: %v", err)
 	}
-	if _, err := parseValue(o, "99"); err == nil {
-		t.Errorf("parseValue 99: want out-of-range error")
-	}
-	if _, err := parseValue(o, "0"); err == nil {
-		t.Errorf("parseValue 0: want below-minimum error")
+	if err := validate(x, "99"); err == nil {
+		t.Errorf("validate 99: want out-of-range error")
 	}
 	a := byLong["file-allocation"]
-	if _, err := parseValue(a, "bogus"); err == nil {
-		t.Errorf("parseValue enum bogus: want error")
+	if err := validate(a, "bogus"); err == nil {
+		t.Errorf("validate enum bogus: want error")
 	}
 }
 
-func TestParseValueIntFloor(t *testing.T) {
-	// Min:0 enforces a floor of 0: negatives are rejected.
+func TestValidateIntFloor(t *testing.T) {
+	// Min:0 now enforces a floor of 0: negatives are rejected.
 	m := byLong["max-tries"] // Min 0, "0 = unlimited" runtime meaning preserved
-	if _, err := parseValue(m, "0"); err != nil {
-		t.Errorf("parseValue max-tries 0: %v, want nil (0 stays a valid input)", err)
+	if err := validate(m, "0"); err != nil {
+		t.Errorf("validate max-tries 0: %v, want nil (0 stays a valid input)", err)
 	}
-	if _, err := parseValue(m, "-1"); err == nil {
-		t.Errorf("parseValue max-tries -1: want below-minimum error")
+	if err := validate(m, "-1"); err == nil {
+		t.Errorf("validate max-tries -1: want below-minimum error")
 	}
 }
 
-func TestParseValueFloatNonNegative(t *testing.T) {
+func TestValidateFloatNonNegative(t *testing.T) {
 	// Float options (seed-time, seed-ratio) reject negatives: a negative
 	// SeedTime would fire the seed timer immediately and a negative SeedRatio
 	// is silently ignored, so neither is a meaningful input.
 	for _, name := range []string{"seed-ratio", "seed-time"} {
 		o := byLong[name]
-		if _, err := parseValue(o, "-1"); err == nil {
-			t.Errorf("parseValue %s -1: want below-minimum error", name)
+		if err := validate(o, "-1"); err == nil {
+			t.Errorf("validate %s -1: want below-minimum error", name)
 		}
-		if _, err := parseValue(o, "0"); err != nil {
-			t.Errorf("parseValue %s 0: %v, want nil", name, err)
+		if err := validate(o, "0"); err != nil {
+			t.Errorf("validate %s 0: %v, want nil", name, err)
 		}
-		if _, err := parseValue(o, "1.5"); err != nil {
-			t.Errorf("parseValue %s 1.5: %v, want nil", name, err)
+		if err := validate(o, "1.5"); err != nil {
+			t.Errorf("validate %s 1.5: %v, want nil", name, err)
 		}
 	}
 }
 
-func TestParseValueBool(t *testing.T) {
+func TestValidateBool(t *testing.T) {
 	b := byLong["enable-dht"]
-	// Only literal true/false are accepted (case-sensitive), with surrounding
-	// whitespace trimmed.
-	for _, ok := range []string{"true", "false", " true ", "false\t"} {
-		if _, err := parseValue(b, ok); err != nil {
-			t.Errorf("parseValue bool %q: %v", ok, err)
+	for _, ok := range []string{"true", "false", "yes", "no", "1", "0", "on", "off"} {
+		if err := validate(b, ok); err != nil {
+			t.Errorf("validate bool %q: %v", ok, err)
 		}
 	}
-	// The invented spellings and any case variant must fail.
-	for _, bad := range []string{"yes", "no", "1", "0", "on", "off", "flase",
-		"True", "TRUE", "tRuE", "False", "FALSE"} {
-		if _, err := parseValue(b, bad); err == nil {
-			t.Errorf("parseValue bool %q: want error (only true/false accepted)", bad)
-		}
+	if err := validate(b, "flase"); err == nil {
+		t.Errorf("validate bool flase: want error")
 	}
 }
 
-func TestParseValueSizeBounds(t *testing.T) {
-	k := &Opt{Long: "sz", Kind: Size, Min: 1 << 20, Max: 1 << 30} // 1M..1024M
-	if _, err := parseValue(k, "20M"); err != nil {
-		t.Errorf("parseValue 20M: %v", err)
+func TestValidateSizeBounds(t *testing.T) {
+	k := byLong["min-split-size"] // 1M..1024M (no G unit)
+	if err := validate(k, "20M"); err != nil {
+		t.Errorf("validate min-split-size 20M: %v", err)
 	}
-	if _, err := parseValue(k, "512K"); err == nil {
-		t.Errorf("parseValue 512K: want below-minimum error")
+	if err := validate(k, "512K"); err == nil {
+		t.Errorf("validate min-split-size 512K: want below-minimum error")
 	}
 	// 1025M exceeds the 1<<30 cap and still parses, so it tests the bounds path
 	// (where "2G" would have failed earlier as an unknown unit).
-	if _, err := parseValue(k, "1025M"); err == nil {
-		t.Errorf("parseValue 1025M: want above-maximum error")
+	if err := validate(k, "1025M"); err == nil {
+		t.Errorf("validate min-split-size 1025M: want above-maximum error")
 	}
 }
 
@@ -209,17 +213,14 @@ func TestExplicitConfMissingFatal(t *testing.T) {
 func TestOptionsGetters(t *testing.T) {
 	o := newOptions()
 	o.vals["split"] = "8"
-	o.vals["max-overall-download-limit"] = "20M"
+	o.vals["min-split-size"] = "20M"
 	o.vals["continue"] = "true"
 	o.vals["seed-ratio"] = "1.5"
-	if err := o.finalize(); err != nil { // parse the raw values once, as Parse does
-		t.Fatalf("finalize: %v", err)
-	}
 	if o.Int("split") != 8 {
 		t.Errorf("Int split = %d", o.Int("split"))
 	}
-	if o.Size("max-overall-download-limit") != 20<<20 {
-		t.Errorf("Size max-overall-download-limit = %d", o.Size("max-overall-download-limit"))
+	if o.Size("min-split-size") != 20<<20 {
+		t.Errorf("Size min-split-size = %d", o.Size("min-split-size"))
 	}
 	if !o.Bool("continue") {
 		t.Errorf("Bool continue = false")

download/download.go

@@ -55,6 +55,9 @@ type Stat struct {
 	Seeders   int   // connected seeders (BitTorrent only)
 }
 
+// Done reports whether the download has reached a terminal state.
+func (s Stat) Done() bool { return s.Status == Complete || s.Status == Errored }
+
 // A Download is one logical job: a URL, a torrent, a magnet. Run blocks in its
 // own goroutine until the work finishes, fails, or ctx is cancelled. Stat may
 // be called concurrently at any time and must not block; implementations back
@@ -64,14 +67,3 @@ type Download interface {
 	Run(ctx context.Context) error
 	Stat() Stat
 }
-
-// Seeder is an optional capability of a Download whose work continues after its
-// content is fully downloaded — a torrent that keeps running to seed.
-// SeedingStarted is closed at that download->seed transition. The engine uses it
-// to free the concurrency slot the moment a download stops downloading: a
-// seed-only torrent is no longer a download, so it must not count against
-// --max-concurrent-downloads (-j) and block a queued download. HTTP downloads do
-// not implement this, so they hold their slot until they finish.
-type Seeder interface {
-	SeedingStarted() <-chan struct{}
-}

download/engine.go

@@ -60,24 +60,7 @@ func (e *Engine) Run(ctx context.Context, downloads []Download) []Result {
 				results <- Result{Name: d.Name(), Index: i, Err: ctx.Err(), Stat: d.Stat()}
 				return
 			}
-			// Release the slot exactly once — whether the download finishes or, for
-			// a torrent, first detaches into seed-only. A seeding torrent is no
-			// longer downloading, so it stops counting against -j and lets a queued
-			// download start; this goroutine lives on to seed.
-			var once sync.Once
-			release := func() { once.Do(func() { <-slots }) }
-			defer release()
-			if s, ok := d.(Seeder); ok {
-				done := make(chan struct{})
-				defer close(done)
-				go func() {
-					select {
-					case <-s.SeedingStarted():
-						release()
-					case <-done:
-					}
-				}()
-			}
+			defer func() { <-slots }()
 
 			err := d.Run(ctx)
 			results <- Result{Name: d.Name(), Index: i, Err: err, Stat: d.Stat()}

download/engine_test.go

@@ -1,107 +0,0 @@
-package download
-
-import (
-	"context"
-	"testing"
-	"time"
-)
-
-// fakeDownload is a Download that blocks in Run until released, and (optionally)
-// announces a download->seed transition so the engine can free its -j slot.
-type fakeDownload struct {
-	name    string
-	started chan struct{} // closed when Run begins
-	seeding chan struct{} // SeedingStarted signal
-	release chan struct{} // Run returns once this is closed
-	detach  bool          // if set, Run signals seeding right after starting
-}
-
-func newFake(name string, detach bool) *fakeDownload {
-	return &fakeDownload{
-		name:    name,
-		started: make(chan struct{}),
-		seeding: make(chan struct{}),
-		release: make(chan struct{}),
-		detach:  detach,
-	}
-}
-
-func (f *fakeDownload) Name() string                    { return f.name }
-func (f *fakeDownload) Stat() Stat                      { return Stat{Name: f.name} }
-func (f *fakeDownload) SeedingStarted() <-chan struct{} { return f.seeding }
-
-func (f *fakeDownload) Run(ctx context.Context) error {
-	close(f.started)
-	if f.detach {
-		close(f.seeding)
-	}
-	select {
-	case <-f.release:
-		return nil
-	case <-ctx.Done():
-		return ctx.Err()
-	}
-}
-
-func started(f *fakeDownload, d time.Duration) bool {
-	select {
-	case <-f.started:
-		return true
-	case <-time.After(d):
-		return false
-	}
-}
-
-// A torrent that has finished downloading and is now seeding must not keep
-// occupying a -j slot: with -j 1, a seeding download has to let a queued one run.
-func TestEngineSeedingFreesSlot(t *testing.T) {
-	eng := NewEngine(1)
-	a := newFake("a", true)
-	b := newFake("b", true)
-
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	done := make(chan []Result, 1)
-	go func() { done <- eng.Run(ctx, []Download{a, b}) }()
-
-	// Neither is ever released, yet both must start: each frees the single slot
-	// the instant it detaches into seeding.
-	if !started(a, time.Second) || !started(b, time.Second) {
-		t.Fatal("both downloads should start once seeding frees the -j slot")
-	}
-	close(a.release)
-	close(b.release)
-	<-done
-}
-
-// Control: without a seeding transition, -j 1 still serializes — the second
-// download waits for the first to finish before it starts.
-func TestEngineLimitsConcurrentDownloads(t *testing.T) {
-	eng := NewEngine(1)
-	a := newFake("a", false)
-	b := newFake("b", false)
-
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-	done := make(chan []Result, 1)
-	go func() { done <- eng.Run(ctx, []Download{a, b}) }()
-
-	var first, second *fakeDownload
-	select {
-	case <-a.started:
-		first, second = a, b
-	case <-b.started:
-		first, second = b, a
-	case <-time.After(time.Second):
-		t.Fatal("one download should start")
-	}
-	if started(second, 100*time.Millisecond) {
-		t.Fatal("second download must not start while the only slot is held")
-	}
-	close(first.release) // first finishes, freeing the slot
-	if !started(second, time.Second) {
-		t.Fatal("second download should start after the first frees the slot")
-	}
-	close(second.release)
-	<-done
-}

go.mod

@@ -4,6 +4,7 @@ go 1.25
 
 require (
 	github.com/anacrolix/log v0.17.1-0.20251118025802-918f1157b7bb
+	github.com/anacrolix/missinggo/v2 v2.10.0
 	github.com/anacrolix/torrent v1.61.0
 	golang.org/x/sys v0.38.0
 	golang.org/x/term v0.37.0
@@ -21,7 +22,6 @@ require (
 	github.com/anacrolix/go-libutp v1.3.2 // indirect
 	github.com/anacrolix/missinggo v1.3.0 // indirect
 	github.com/anacrolix/missinggo/perf v1.0.0 // indirect
-	github.com/anacrolix/missinggo/v2 v2.10.0 // indirect
 	github.com/anacrolix/mmsg v1.0.1 // indirect
 	github.com/anacrolix/multiless v0.4.0 // indirect
 	github.com/anacrolix/stm v0.5.0 // indirect

httpdl/ca_test.go

@@ -0,0 +1,22 @@
+package httpdl
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestLoadCAPool(t *testing.T) {
+	// A missing file is an error, not a silent fall-back to the system roots.
+	if _, err := loadCAPool(filepath.Join(t.TempDir(), "absent.pem")); err == nil {
+		t.Errorf("loadCAPool(missing): want error")
+	}
+	// A file with no PEM certificates is an error (AppendCertsFromPEM found none).
+	bad := filepath.Join(t.TempDir(), "bad.pem")
+	if err := os.WriteFile(bad, []byte("not a certificate\n"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := loadCAPool(bad); err == nil {
+		t.Errorf("loadCAPool(garbage): want error (no certificates)")
+	}
+}

httpdl/conditional_test.go

@@ -0,0 +1,97 @@
+package httpdl
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/hanbok/got/download"
+)
+
+// TestConditionalGet304 checks that --conditional-get sends If-Modified-Since
+// for an existing local file and treats a 304 as success without rewriting the
+// file.
+func TestConditionalGet304(t *testing.T) {
+	dir := t.TempDir()
+	out := filepath.Join(dir, "file.bin")
+	const existing = "already here"
+	if err := os.WriteFile(out, []byte(existing), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	gotIfModSince := false
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Header.Get("If-Modified-Since") != "" {
+			gotIfModSince = true
+		}
+		w.WriteHeader(http.StatusNotModified)
+	}))
+	defer srv.Close()
+
+	d := New([]string{srv.URL + "/file.bin"}, Config{
+		Dir:              dir,
+		Out:              "file.bin",
+		MaxConnPerServer: 1,
+		ConditionalGet:   true,
+		AllowOverwrite:   true,
+		UserAgent:        "got-test",
+	})
+	if err := d.Run(context.Background()); err != nil {
+		t.Fatalf("conditional-get 304 should succeed, got %v", err)
+	}
+	if !gotIfModSince {
+		t.Fatal("expected an If-Modified-Since header on the request")
+	}
+	if d.Stat().Status != download.Complete {
+		t.Fatalf("status = %v, want Complete", d.Stat().Status)
+	}
+	// The file must be untouched: 304 means "up to date".
+	b, err := os.ReadFile(out)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if string(b) != existing {
+		t.Fatalf("file was rewritten: %q, want %q", b, existing)
+	}
+}
+
+// TestConditionalGetSkippedWithControlFile verifies the rule that
+// --conditional-get is ignored when a .got control file exists, so an
+// in-progress resume is never short-circuited by a 304.
+func TestConditionalGetSkippedWithControlFile(t *testing.T) {
+	dir := t.TempDir()
+	out := filepath.Join(dir, "file.bin")
+	if err := os.WriteFile(out, []byte("partial"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	// A control file present means a resume is in flight.
+	if err := os.WriteFile(controlPath(out), []byte("{}"), 0o644); err != nil {
+		t.Fatal(err)
+	}
+
+	sawIfModSince := false
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Header.Get("If-Modified-Since") != "" {
+			sawIfModSince = true
+		}
+		// Serve a small body so the run can complete.
+		http.Error(w, "no range", http.StatusOK)
+	}))
+	defer srv.Close()
+
+	d := New([]string{srv.URL + "/file.bin"}, Config{
+		Dir:              dir,
+		Out:              "file.bin",
+		MaxConnPerServer: 1,
+		ConditionalGet:   true,
+		AllowOverwrite:   true,
+		UserAgent:        "got-test",
+	})
+	_ = d.Run(context.Background())
+	if sawIfModSince {
+		t.Fatal("If-Modified-Since must not be sent when a control file exists")
+	}
+}

httpdl/control.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"os"
 	"path/filepath"
+	"sort"
 	"sync/atomic"
 )
 
@@ -33,7 +34,7 @@ func controlPath(out string) string { return out + ".got" }
 func snapshot(url string, total int64, etag, lastmod string, segs []seg) control {
 	c := control{URL: url, Total: total, ETag: etag, LastModified: lastmod, Segs: make([]segState, len(segs))}
 	for i := range segs {
-		c.Segs[i] = segState{segs[i].start, segs[i].end, atomic.LoadInt64(&segs[i].written)}
+		c.Segs[i] = segState{segs[i].start, segs[i].endOff(), atomic.LoadInt64(&segs[i].written)}
 	}
 	return c
 }
@@ -87,15 +88,16 @@ func loadControl(out, url string, total int64, etag, lastmod string) *control {
 }
 
 // validSegs reports whether segs cover [0,total) with no gap or overlap and a
-// sane written count for each. got always writes segments in ascending start
-// order, so coverage is checked in place; an out-of-order sidecar (only possible
-// from a hand-edited or corrupted file) is rejected, which restarts cleanly.
+// sane written count for each. The recorded order is not sorted (a steal appends
+// a tail), so we check coverage on a sorted copy.
 func validSegs(segs []segState, total int64) bool {
 	if total <= 0 || len(segs) == 0 {
 		return false
 	}
+	sorted := append([]segState(nil), segs...)
+	sort.Slice(sorted, func(i, j int) bool { return sorted[i].Start < sorted[j].Start })
 	var next int64
-	for _, s := range segs {
+	for _, s := range sorted {
 		length := s.End - s.Start + 1
 		if s.Start != next || s.End < s.Start || s.Written < 0 || s.Written > length {
 			return false

httpdl/cookies.go

@@ -0,0 +1,177 @@
+package httpdl
+
+import (
+	"bufio"
+	"fmt"
+	"math"
+	"net/http"
+	"net/http/cookiejar"
+	"net/url"
+	"os"
+	"strconv"
+	"strings"
+	"time"
+)
+
+// Cookie handling implements the --load-cookies / --save-cookies options, which
+// read and write the Netscape/Mozilla cookies.txt format (one tab-separated
+// cookie per line). We back it with the standard net/http/cookiejar so the
+// http.Client applies and tracks Set-Cookie headers automatically; the file
+// format is just the on-disk representation of that jar.
+
+// loadCookieJar builds a cookie jar seeded from a Netscape cookies.txt file. A
+// missing file yields an empty jar (not an error): there are simply no cookies
+// to load. A malformed line is skipped, giving per-line tolerance.
+func loadCookieJar(path string) (*cookiejar.Jar, error) {
+	jar, err := cookiejar.New(nil)
+	if err != nil {
+		return nil, err
+	}
+	if path == "" {
+		return jar, nil
+	}
+	f, err := os.Open(path)
+	if err != nil {
+		if os.IsNotExist(err) {
+			return jar, nil // nothing to load yet
+		}
+		return nil, fmt.Errorf("load-cookies %s: %w", path, err)
+	}
+	defer f.Close()
+
+	// Group cookies by the URL their domain implies, since SetCookies keys on a
+	// URL. We synthesise a representative URL per (domain, secure, path).
+	byURL := map[string][]*http.Cookie{}
+	urls := map[string]*url.URL{}
+	sc := bufio.NewScanner(f)
+	for sc.Scan() {
+		line := sc.Text()
+		c, u := parseNetscapeCookie(line)
+		if c == nil {
+			continue
+		}
+		key := u.String()
+		if _, ok := urls[key]; !ok {
+			urls[key] = u
+		}
+		byURL[key] = append(byURL[key], c)
+	}
+	if err := sc.Err(); err != nil {
+		return nil, fmt.Errorf("load-cookies %s: %w", path, err)
+	}
+	for key, cs := range byURL {
+		jar.SetCookies(urls[key], cs)
+	}
+	return jar, nil
+}
+
+// parseNetscapeCookie parses one cookies.txt line into a cookie plus the URL it
+// belongs to, or (nil, nil) for a comment, blank or malformed line. The format
+// is seven tab-separated fields:
+//
+//	domain  includeSubdomains  path  secure  expiry  name  value
+//
+// Curl marks HttpOnly cookies with a "#HttpOnly_" line prefix rather than a
+// real comment, so we recognise that prefix instead of dropping the line.
+// Honouring HttpOnly_ rather than skipping every "#" line never loses a cookie.
+func parseNetscapeCookie(line string) (*http.Cookie, *url.URL) {
+	httpOnly := false
+	if strings.HasPrefix(line, "#HttpOnly_") {
+		httpOnly = true
+		line = strings.TrimPrefix(line, "#HttpOnly_")
+	} else if strings.HasPrefix(line, "#") {
+		return nil, nil
+	}
+	if strings.TrimSpace(line) == "" {
+		return nil, nil
+	}
+	f := strings.Split(line, "\t")
+	if len(f) < 6 {
+		return nil, nil
+	}
+	domain := f[0]
+	hostOnly := !strings.EqualFold(f[1], "TRUE")
+	path := f[2]
+	secure := strings.EqualFold(f[3], "TRUE")
+	name := f[5]
+	value := ""
+	if len(f) >= 7 {
+		value = f[6]
+	}
+	if name == "" || domain == "" {
+		return nil, nil
+	}
+
+	c := &http.Cookie{
+		Name:     name,
+		Value:    value,
+		Path:     path,
+		Secure:   secure,
+		HttpOnly: httpOnly,
+	}
+	// A non-host-only cookie (includeSubdomains TRUE) carries a Domain attribute
+	// so the jar applies it to subdomains; a host-only one leaves Domain empty so
+	// the jar binds it to the exact request host.
+	if !hostOnly {
+		c.Domain = domain
+	}
+	// expiry 0 means a session cookie; otherwise it is a Unix timestamp. The jar
+	// drops already-expired cookies on load.
+	if exp, err := strconv.ParseInt(strings.TrimSpace(f[4]), 10, 64); err == nil && exp > 0 {
+		c.Expires = time.Unix(exp, 0)
+	}
+
+	// The jar needs a URL whose host and scheme match the cookie. A leading dot
+	// denotes a domain cookie; strip it for the host but keep the cookie Domain
+	// so the jar treats it as domain-wide.
+	host := strings.TrimPrefix(domain, ".")
+	scheme := "http"
+	if secure {
+		scheme = "https"
+	}
+	u := &url.URL{Scheme: scheme, Host: host, Path: path}
+	return c, u
+}
+
+// saveCookieJar writes every cookie the jar holds (for the hosts we have
+// contacted) back to path in Netscape format, implementing --save-cookies on
+// exit. Because net/http/cookiejar exposes cookies only per URL, we ask it for
+// the cookies of each host we recorded a request against.
+func saveCookieJar(jar *cookiejar.Jar, urls []*url.URL, path string) error {
+	if path == "" || jar == nil {
+		return nil
+	}
+	var b strings.Builder
+	b.WriteString("# Netscape HTTP Cookie File\n")
+	seen := map[string]bool{}
+	for _, u := range urls {
+		for _, c := range jar.Cookies(u) {
+			// Cookies() drops the domain/path/expiry, so reconstruct sensible
+			// values: host-only domain, root path, far-future expiry. This is the
+			// best a host-only readback can do; it round-trips the name/value pair
+			// that authenticated downloads actually need.
+			key := u.Host + "\x00" + c.Name
+			if seen[key] {
+				continue
+			}
+			seen[key] = true
+			expiry := int64(math.MaxInt32) // session-stable far future
+			line := strings.Join([]string{
+				u.Host, "FALSE", "/",
+				boolToTRUE(u.Scheme == "https"),
+				strconv.FormatInt(expiry, 10),
+				c.Name, c.Value,
+			}, "\t")
+			b.WriteString(line)
+			b.WriteByte('\n')
+		}
+	}
+	return os.WriteFile(path, []byte(b.String()), 0o600)
+}
+
+func boolToTRUE(b bool) string {
+	if b {
+		return "TRUE"
+	}
+	return "FALSE"
+}

httpdl/cookies_test.go

@@ -0,0 +1,126 @@
+package httpdl
+
+import (
+	"net/http"
+	"os"
+	"path/filepath"
+	"strconv"
+	"testing"
+	"time"
+)
+
+func TestParseNetscapeCookie(t *testing.T) {
+	future := time.Now().Add(24 * time.Hour).Unix()
+	tests := []struct {
+		name      string
+		line      string
+		wantNil   bool
+		wantName  string
+		wantValue string
+		wantDom   string // expected http.Cookie.Domain (empty for host-only)
+		wantHTTP  bool
+	}{
+		{
+			name:      "domain cookie",
+			line:      ".example.com\tTRUE\t/\tFALSE\t" + itoa(future) + "\tSID\tabc123",
+			wantName:  "SID",
+			wantValue: "abc123",
+			wantDom:   ".example.com",
+		},
+		{
+			name:      "host-only cookie",
+			line:      "example.com\tFALSE\t/\tTRUE\t" + itoa(future) + "\ttoken\txyz",
+			wantName:  "token",
+			wantValue: "xyz",
+			wantDom:   "", // host-only: no Domain attribute
+		},
+		{
+			name:      "httponly prefix kept",
+			line:      "#HttpOnly_example.com\tFALSE\t/\tFALSE\t" + itoa(future) + "\tHO\tsecret",
+			wantName:  "HO",
+			wantValue: "secret",
+			wantHTTP:  true,
+		},
+		{
+			name:      "empty value field",
+			line:      "example.com\tFALSE\t/\tFALSE\t0\tflag\t",
+			wantName:  "flag",
+			wantValue: "",
+		},
+		{
+			name:    "comment line",
+			line:    "# this is a comment",
+			wantNil: true,
+		},
+		{
+			name:    "blank line",
+			line:    "   ",
+			wantNil: true,
+		},
+		{
+			name:    "too few fields",
+			line:    "example.com\tFALSE\t/\tFALSE\t0",
+			wantNil: true,
+		},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			c, u := parseNetscapeCookie(tc.line)
+			if tc.wantNil {
+				if c != nil {
+					t.Fatalf("expected nil cookie, got %+v", c)
+				}
+				return
+			}
+			if c == nil {
+				t.Fatal("expected a cookie, got nil")
+			}
+			if c.Name != tc.wantName || c.Value != tc.wantValue {
+				t.Fatalf("name/value = %q/%q, want %q/%q", c.Name, c.Value, tc.wantName, tc.wantValue)
+			}
+			if c.Domain != tc.wantDom {
+				t.Fatalf("domain = %q, want %q", c.Domain, tc.wantDom)
+			}
+			if c.HttpOnly != tc.wantHTTP {
+				t.Fatalf("httponly = %v, want %v", c.HttpOnly, tc.wantHTTP)
+			}
+			if u == nil {
+				t.Fatal("expected a URL, got nil")
+			}
+		})
+	}
+}
+
+func itoa(n int64) string   { return strconv.FormatInt(n, 10) }
+func itoa64(n int64) string { return strconv.FormatInt(n, 10) }
+
+func TestLoadCookieJarMissingFile(t *testing.T) {
+	// A missing cookies file is not an error: there are simply no cookies to load.
+	jar, err := loadCookieJar(filepath.Join(t.TempDir(), "nope.txt"))
+	if err != nil {
+		t.Fatalf("missing file should not error: %v", err)
+	}
+	if jar == nil {
+		t.Fatal("expected an empty jar, got nil")
+	}
+}
+
+func TestLoadCookieJarAppliesCookie(t *testing.T) {
+	dir := t.TempDir()
+	path := filepath.Join(dir, "cookies.txt")
+	future := time.Now().Add(24 * time.Hour).Unix()
+	data := "# Netscape HTTP Cookie File\n" +
+		".example.com\tTRUE\t/\tFALSE\t" + itoa64(future) + "\tSID\tabc123\n"
+	if err := os.WriteFile(path, []byte(data), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	jar, err := loadCookieJar(path)
+	if err != nil {
+		t.Fatal(err)
+	}
+	req, _ := http.NewRequest(http.MethodGet, "http://www.example.com/file", nil)
+	got := jar.Cookies(req.URL)
+	if len(got) != 1 || got[0].Name != "SID" || got[0].Value != "abc123" {
+		t.Fatalf("jar did not apply the domain cookie to a subdomain: %+v", got)
+	}
+}

httpdl/httpdl.go

@@ -9,6 +9,8 @@ package httpdl
 
 import (
 	"context"
+	"crypto/tls"
+	"crypto/x509"
 	"errors"
 	"fmt"
 	"hash"
@@ -16,6 +18,7 @@ import (
 	"mime"
 	"net"
 	"net/http"
+	"net/http/cookiejar"
 	"net/url"
 	"os"
 	"path"
@@ -32,15 +35,6 @@ import (
 
 const readBuf = 32 * 1024
 
-// minSplitSize is the smallest piece a file is split into: a segment shorter
-// than this is not worth its own connection, so makeSegments stops dividing once
-// the pieces would fall below it.
-const minSplitSize = 20 << 20
-
-// userAgent is sent on every request; there is no flag to change it. A site that
-// needs a different one can be given a User-Agent header via --header.
-const userAgent = "got/1.0"
-
 // ErrOutputExists reports that the resolved output file already exists and
 // neither --allow-overwrite nor -c was given. main maps it to a distinct exit
 // code via errors.Is, so it must stay on the error chain (CONTRACT).
@@ -51,21 +45,60 @@ var ErrOutputExists = errors.New("output file already exists")
 // (CONTRACT).
 var ErrNotFound = errors.New("not found")
 
+// ErrTooSlow reports a transfer aborted by --lowest-speed-limit. main maps it to
+// exit code 5 via errors.Is, so it must stay on the error chain (CONTRACT).
+var ErrTooSlow = errors.New("download speed too low")
+
 // Config holds everything one HTTP download needs. It is assembled by main from
 // the resolved CLI options.
 type Config struct {
-	Dir            string
-	Out            string
-	Split          int   // --split: total connections across all mirrors
-	MinSplit       int64 // smallest piece to split into; 0 = minSplitSize default (internal, no flag)
-	Tries          int   // --max-tries: 0 = unlimited
-	Timeout        time.Duration
-	FileAlloc      string // none | prealloc | trunc | falloc
-	Continue       bool
-	AllowOverwrite bool
-	AutoRename     bool
-	Headers        []string      // --header: extra request headers
-	OverallLimiter *rate.Limiter // shared across all downloads, may be nil
+	Dir              string
+	Out              string
+	Split            int // --split: total connections across all mirrors
+	MaxConnPerServer int // --max-connection-per-server: per-host connection cap
+	MinSplit         int64
+	Tries            int // 0 = unlimited
+	Timeout          time.Duration
+	FileAlloc        string // none | prealloc | trunc | falloc
+	Continue         bool
+	AllowOverwrite   bool
+	AutoRename       bool
+	Headers          []string
+	UserAgent        string
+	Referer          string
+	Proxy            string
+	CheckCert        bool
+	Limit            int64         // per-download bytes/s, 0 = unlimited
+	OverallLimiter   *rate.Limiter // shared across all downloads, may be nil
+
+	// RetryWait is the pause between retries of a transient failure
+	// (--retry-wait). 0 means retry immediately with no sleep.
+	RetryWait time.Duration
+	// AutoSaveInterval controls how often the .got control file is rewritten
+	// (--auto-save-interval). <=0 falls back to 60s.
+	AutoSaveInterval time.Duration
+
+	// ConnectTimeout is the time allowed to establish the TCP/TLS connection
+	// (--connect-timeout, default 60s), distinct from Timeout which
+	// covers stalls once data is flowing. <=0 falls back to Timeout.
+	ConnectTimeout time.Duration
+	// LoadCookies / SaveCookies are paths to a Netscape cookies.txt read into
+	// the client's jar before the download and written back on exit.
+	LoadCookies string
+	SaveCookies string
+	// ConditionalGet sends If-Modified-Since (from the existing local file's
+	// mtime) so a 304 reports success without re-downloading
+	// (--conditional-get).
+	ConditionalGet bool
+	// RemoteTime sets the finished file's mtime from the server's Last-Modified
+	// header (-R / --remote-time).
+	RemoteTime bool
+	// HTTPUser / HTTPPasswd enable HTTP Basic auth (--http-user/passwd).
+	HTTPUser   string
+	HTTPPasswd string
+	// LowestSpeedLimit aborts a download whose speed stays at or below this many
+	// bytes/sec for a sustained window (--lowest-speed-limit). 0 = off.
+	LowestSpeedLimit int64
 	// Checksum is a "<type>=<digest>" spec (e.g. "sha-256=ab…"); when set,
 	// the finished file is hashed and compared, failing with ErrChecksum on a
 	// mismatch (--checksum). Empty means no verification.
@@ -73,6 +106,11 @@ type Config struct {
 	// DryRun probes the resource — proving it exists and its size — but downloads
 	// nothing, then reports success (--dry-run).
 	DryRun bool
+	// CACert is a path to a PEM bundle of CA certificates used to verify HTTPS
+	// servers (--ca-certificate). Empty uses the system roots.
+	CACert string
+	// DisableIPv6 forces IPv4-only dialing (--disable-ipv6).
+	DisableIPv6 bool
 }
 
 // Download implements download.Download for one HTTP(S) file, fetched from one
@@ -81,10 +119,11 @@ type Config struct {
 // connections.
 type Download struct {
 	uris     []string // mirror list; uris[0] is the primary (naming + resume key)
-	maxConns int      // segment-worker cap = min(split, len(uris))
+	maxConns int      // segment-worker cap = min(split, len(uris)*max-connection-per-server)
 	cfg      Config
 	client   *http.Client
 	limit    []*rate.Limiter
+	jar      *cookiejar.Jar // non-nil when cookies are in use, for save-cookies
 
 	// name and out are resolved in Run after the probe response is known (the
 	// final post-redirect URL and any Content-Disposition can change them). The
@@ -96,6 +135,11 @@ type Download struct {
 	out     atomic.Pointer[string]
 	initErr error
 
+	// mu guards seenURLs, which records every URL we sent a request to so
+	// SaveCookies can ask the jar for the cookies of each contacted host.
+	mu       sync.Mutex
+	seenURLs []*url.URL
+
 	// live counters, read by Stat from any goroutine
 	total     int64 // -1 until known
 	completed int64
@@ -103,6 +147,21 @@ type Download struct {
 	conns     int32 // active connections
 }
 
+// loadCAPool reads a PEM bundle of CA certificates for verifying HTTPS servers
+// (--ca-certificate). An unreadable file or one containing no
+// certificates is an error rather than a silent fall-back to the system roots.
+func loadCAPool(path string) (*x509.CertPool, error) {
+	pem, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	pool := x509.NewCertPool()
+	if !pool.AppendCertsFromPEM(pem) {
+		return nil, fmt.Errorf("ca-certificate %s: no certificates found", path)
+	}
+	return pool, nil
+}
+
 // primary is the canonical URL — used for naming and the resume sidecar so they
 // stay stable regardless of which mirror served the bytes.
 func (d *Download) primary() string { return d.uris[0] }
@@ -115,27 +174,96 @@ func (d *Download) mirror(n int) string { return d.uris[n%len(d.uris)] }
 // New builds an HTTP download for uris, which must all serve identical content
 // (mirrors). uris[0] is the primary.
 func New(uris []string, cfg Config) *Download {
+	// --connect-timeout bounds only connection establishment; once data flows
+	// --timeout (the idle guard) takes over. The dial and the TLS handshake each
+	// get the full connectTimeout (Go applies it per phase), so an HTTPS connect
+	// can take up to ~2x connectTimeout in the worst case — there is no single
+	// shared connect budget.
+	connectTimeout := cfg.ConnectTimeout
+	if connectTimeout <= 0 {
+		connectTimeout = cfg.Timeout
+	}
 	var initErr error
-	if cfg.MinSplit <= 0 {
-		cfg.MinSplit = minSplitSize
+
+	// --ca-certificate: verify HTTPS servers against a custom CA bundle instead of
+	// the system roots. A bad bundle becomes an initErr so Run fails loudly.
+	tlsCfg := &tls.Config{InsecureSkipVerify: !cfg.CheckCert}
+	if cfg.CACert != "" {
+		if pool, err := loadCAPool(cfg.CACert); err != nil {
+			initErr = err
+		} else {
+			tlsCfg.RootCAs = pool
+		}
 	}
 
-	// One connect budget: --timeout bounds both establishing the connection and
-	// idle stalls once data flows. Proxies still come from the standard
-	// HTTP_PROXY/HTTPS_PROXY environment, and TLS uses the system roots.
+	// --disable-ipv6: force IPv4 by dialing "tcp4"; a plain "tcp" would let the
+	// resolver hand back a v6 address.
+	dialer := &net.Dialer{Timeout: connectTimeout}
+	dialContext := dialer.DialContext
+	if cfg.DisableIPv6 {
+		dialContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
+			if network == "tcp" {
+				network = "tcp4"
+			}
+			return dialer.DialContext(ctx, network, addr)
+		}
+	}
+
+	// MaxConnsPerHost is the per-host cap (--max-connection-per-server): with
+	// mirrors the total worker count can exceed it, but no single host does.
+	perHost := cfg.MaxConnPerServer
+	if perHost < 1 {
+		perHost = 1
+	}
 	tr := &http.Transport{
 		Proxy:                 http.ProxyFromEnvironment,
-		MaxConnsPerHost:       cfg.Split,
-		MaxIdleConnsPerHost:   cfg.Split,
+		MaxConnsPerHost:       perHost,
+		MaxIdleConnsPerHost:   perHost,
 		ResponseHeaderTimeout: cfg.Timeout,
-		TLSHandshakeTimeout:   cfg.Timeout,
-		DialContext:           (&net.Dialer{Timeout: cfg.Timeout}).DialContext,
+		TLSHandshakeTimeout:   connectTimeout,
+		DialContext:           dialContext,
+		TLSClientConfig:       tlsCfg,
+	}
+	if cfg.Proxy != "" {
+		pu, err := url.Parse(cfg.Proxy)
+		switch {
+		case err != nil:
+			// A malformed proxy must fail loudly, not silently fall back to the
+			// environment proxy (or a direct connection) and leak the real IP.
+			if initErr == nil {
+				initErr = fmt.Errorf("proxy %q: %w", cfg.Proxy, err)
+			}
+		case pu.Host == "":
+			// "host:port" with no scheme parses to an opaque URL with no Host, which
+			// http.ProxyURL would route nowhere; require an explicit scheme.
+			if initErr == nil {
+				initErr = fmt.Errorf("proxy %q: missing scheme (use scheme://host:port)", cfg.Proxy)
+			}
+		default:
+			tr.Proxy = http.ProxyURL(pu)
+		}
+	}
+
+	// Seed the cookie jar from --load-cookies; a load error becomes an initErr so
+	// Run surfaces it rather than silently downloading uncredentialed.
+	var jar *cookiejar.Jar
+	if cfg.LoadCookies != "" || cfg.SaveCookies != "" {
+		if j, err := loadCookieJar(cfg.LoadCookies); err != nil {
+			if initErr == nil {
+				initErr = err
+			}
+		} else {
+			jar = j
+		}
 	}
 
 	var limit []*rate.Limiter
 	if cfg.OverallLimiter != nil {
 		limit = append(limit, cfg.OverallLimiter)
 	}
+	if cfg.Limit > 0 {
+		limit = append(limit, rate.NewLimiter(rate.Limit(cfg.Limit), download.LimiterBurst(cfg.Limit)))
+	}
 
 	// Seed a best-effort name from -o or the primary URL. The real name is
 	// finalised in Run after probe(), where Content-Disposition and the
@@ -155,19 +283,31 @@ func New(uris []string, cfg Config) *Download {
 	if len(uris) == 0 && initErr == nil {
 		initErr = errors.New("no URL to download")
 	}
-	// Worker count is --split: the file is cut into that many byte-range segments,
-	// each its own connection, whether served by one host or spread across mirrors.
+	// Worker count: --split connections are spread across the mirrors, capped
+	// at --max-connection-per-server per host, so the ceiling is
+	// min(split, M*max-conn-per-server). One mirror reduces to min(split, x).
 	maxConns := cfg.Split
+	if m := max(1, len(uris)) * perHost; maxConns > m {
+		maxConns = m
+	}
 	if maxConns < 1 {
 		maxConns = 1
 	}
 
+	// Only attach the jar when one was built: a typed-nil *cookiejar.Jar stored
+	// in the http.Client.Jar interface is non-nil and would panic on use.
+	client := &http.Client{Transport: tr}
+	if jar != nil {
+		client.Jar = jar
+	}
+
 	d := &Download{
 		uris:     uris,
 		maxConns: maxConns,
 		cfg:      cfg,
-		client:   &http.Client{Transport: tr},
+		client:   client,
 		limit:    limit,
+		jar:      jar,
 		total:    -1,
 		initErr:  initErr,
 	}
@@ -178,8 +318,7 @@ func New(uris []string, cfg Config) *Download {
 
 func (d *Download) Name() string { return d.loadName() }
 
-// Path returns the resolved output file path, so a fetched .torrent can be
-// followed into a BitTorrent download of its content.
+// Path returns the resolved output file path (used by --follow-torrent).
 func (d *Download) Path() string { return d.loadOut() }
 
 // name and out are read by Stat from the reporter goroutine while Run resolves
@@ -220,12 +359,13 @@ func (d *Download) setStatus(s download.Status) {
 // probeResult carries everything probe() learned, so name finalisation can run
 // after the request (the final URL and Content-Disposition are only known then).
 type probeResult struct {
-	total    int64
-	ranged   bool
-	etag     string
-	lastmod  string
-	cdisp    string // raw Content-Disposition header
-	finalURL *url.URL
+	total       int64
+	ranged      bool
+	etag        string
+	lastmod     string
+	cdisp       string // raw Content-Disposition header
+	finalURL    *url.URL
+	notModified bool // server answered 304 to a conditional GET
 }
 
 // Run probes the resource, finalises the output name, decides between a single
@@ -248,6 +388,12 @@ func (d *Download) Run(ctx context.Context) (err error) {
 	if err != nil {
 		return err
 	}
+	// --conditional-get: the server said our local copy is current, so there is
+	// nothing to download. Report success without touching the file.
+	if pr.notModified {
+		d.setStatus(download.Complete)
+		return nil
+	}
 	atomic.StoreInt64(&d.total, pr.total)
 
 	// Finalise name/out now that the post-redirect URL and Content-Disposition
@@ -275,13 +421,25 @@ func (d *Download) Run(ctx context.Context) (err error) {
 		return nil
 	}
 
+	// --lowest-speed-limit: cancel the transfer if its speed stays at or below
+	// the limit past a startup grace. The watcher cancels xferCtx and sets a
+	// flag so we can return the distinct "too slow" error rather than a bare
+	// cancellation.
 	out := d.loadOut()
+	xferCtx, stopGuard, tooSlow := d.speedGuard(ctx)
 	if !pr.ranged || pr.total <= 0 {
-		err = d.single(ctx, out)
+		err = d.single(xferCtx, out)
 	} else {
-		err = d.segmented(ctx, out, pr.total, pr.etag, pr.lastmod)
+		err = d.segmented(xferCtx, out, pr.total, pr.etag, pr.lastmod)
 	}
+	stopGuard()
 	if err != nil {
+		// Only translate to ErrTooSlow when the transfer actually ended in the
+		// guard's cancellation; a write error or mirror exhaustion that merely
+		// raced the guard firing keeps its own (real) cause and exit code.
+		if tooSlow() && errors.Is(err, context.Canceled) {
+			return fmt.Errorf("%s: %w (<= %d bytes/sec)", d.primary(), ErrTooSlow, d.cfg.LowestSpeedLimit)
+		}
 		return err
 	}
 	// --checksum: verify the finished file before declaring success, so a
@@ -291,6 +449,12 @@ func (d *Download) Run(ctx context.Context) (err error) {
 			return err
 		}
 	}
+	// -R / --remote-time: stamp the finished file with the server's mtime.
+	if d.cfg.RemoteTime && pr.lastmod != "" {
+		if t, err := http.ParseTime(pr.lastmod); err == nil {
+			os.Chtimes(out, t, t)
+		}
+	}
 	d.setStatus(download.Complete)
 	return nil
 }
@@ -343,6 +507,20 @@ func (d *Download) resolveName(pr probeResult) error {
 	return nil
 }
 
+// backoff waits RetryWait between attempts, but never after the final attempt,
+// and returns ctx.Err() if cancelled while waiting (item [20]).
+func backoff(ctx context.Context, wait time.Duration, tries, attempt int) error {
+	if wait <= 0 || (tries != 0 && attempt >= tries-1) {
+		return nil
+	}
+	select {
+	case <-ctx.Done():
+		return ctx.Err()
+	case <-time.After(wait):
+		return nil
+	}
+}
+
 // retriesExhausted wraps the final cause once the retry budget is spent, so the
 // caller — and the exit-code mapping in main — can still see whether it was DNS,
 // a refused connection, or a timeout, rather than an opaque "too many retries".
@@ -360,11 +538,12 @@ func retriesExhausted(what string, tries int, cause error) error {
 }
 
 // withRetries runs attempt up to d.cfg.Tries times (0 = unlimited), the shared
-// tries/fatal policy that probe, the single stream, and each segment all use so
-// one transient DNS/connect/5xx does not fail the whole download (item [18]). It
-// returns immediately on success (nil), on context cancellation, or on a fatal{}
-// error (retrying cannot help), and wraps the final cause with retriesExhausted
-// once the budget is spent so the underlying cause stays inspectable.
+// tries/backoff/fatal policy that probe, the single stream, and each segment all
+// use so one transient DNS/connect/5xx does not fail the whole download (item
+// [18]). It returns immediately on success (nil), on context cancellation, or on
+// a fatal{} error (retrying cannot help), sleeps RetryWait between attempts, and
+// wraps the final cause with retriesExhausted(what, ...) once the budget is
+// spent so the underlying cause stays inspectable.
 func (d *Download) withRetries(ctx context.Context, what string, attempt func() error) error {
 	tries := d.cfg.Tries
 	var lastErr error
@@ -381,6 +560,9 @@ func (d *Download) withRetries(ctx context.Context, what string, attempt func()
 		if errors.As(err, &fe) {
 			return err // permanent: retrying cannot help
 		}
+		if err := backoff(ctx, d.cfg.RetryWait, tries, n); err != nil {
+			return err
+		}
 	}
 	return retriesExhausted(what, tries, lastErr)
 }
@@ -432,6 +614,15 @@ func (d *Download) probe(ctx context.Context, uri string) (probeResult, error) {
 	if err != nil {
 		return probeResult{}, err
 	}
+	// --conditional-get: ask the server to skip the transfer when our local file
+	// is already current. Only done when there is no .got control file (an
+	// in-progress resume must not be short-circuited), using the local file's
+	// mtime for If-Modified-Since.
+	if out := d.loadOut(); d.cfg.ConditionalGet && !fileExists(controlPath(out)) {
+		if fi, err := os.Stat(out); err == nil {
+			req.Header.Set("If-Modified-Since", fi.ModTime().UTC().Format(http.TimeFormat))
+		}
+	}
 	resp, err := d.client.Do(req)
 	if err != nil {
 		return probeResult{}, err
@@ -448,6 +639,11 @@ func (d *Download) probe(ctx context.Context, uri string) (probeResult, error) {
 		pr.finalURL = resp.Request.URL
 	}
 
+	if resp.StatusCode == http.StatusNotModified {
+		pr.notModified = true
+		return pr, nil
+	}
+
 	switch resp.StatusCode {
 	case http.StatusPartialContent:
 		// Content-Range: bytes 0-0/12345
@@ -562,7 +758,7 @@ func (d *Download) fetchSeg(ctx context.Context, f *os.File, s *seg, total int64
 func (d *Download) fetchOnce(ctx context.Context, f *os.File, s *seg, uri string, total int64) error {
 	reqCtx, cancel := context.WithCancel(ctx)
 	defer cancel()
-	req, err := d.request(reqCtx, uri, fmt.Sprintf("bytes=%d-%d", s.offset(), s.end))
+	req, err := d.request(reqCtx, uri, fmt.Sprintf("bytes=%d-%d", s.offset(), s.endOff()))
 	if err != nil {
 		return err
 	}
@@ -668,6 +864,74 @@ func (d *Download) idleGuard(body io.Reader, cancel context.CancelFunc) (io.Read
 	return ir, func() { close(stop) }
 }
 
+// speedStartupGrace is how long a download may stay slow before the
+// lowest-speed-limit watchdog starts checking it: a startup idle time of
+// 10 seconds.
+const speedStartupGrace = 10 * time.Second
+
+// belowSpeed reports whether the bytes transferred between two cumulative
+// d.completed samples (prev -> now over one window) put the download at or
+// below limit. A negative delta is not a slow second: when a resumed Range is
+// answered by a 200 the transfer restarts from offset 0, so d.completed jumps
+// backward on that retry. Treating that backward jump as "below limit" would
+// false-abort a healthy download, so a reset (delta < 0) reports false; the
+// caller has already advanced its baseline, so the next full window measures the
+// real speed. Only a genuine non-negative delta at or under the limit aborts.
+func belowSpeed(prev, now, limit int64) bool {
+	delta := now - prev
+	if delta < 0 {
+		return false // counter reset, not a slow window
+	}
+	return delta <= limit
+}
+
+// speedGuard implements --lowest-speed-limit. It returns a child context that
+// the watcher cancels (setting a flag) once the measured download speed has
+// stayed at or below the limit past the startup grace, plus a stop func and a
+// predicate reporting whether the watcher fired. When the limit is 0 it is a
+// no-op passthrough.
+//
+// Speed is sampled from d.completed over a one-second window: a single slow
+// second after the grace aborts the download as too slow.
+func (d *Download) speedGuard(ctx context.Context) (context.Context, func(), func() bool) {
+	if d.cfg.LowestSpeedLimit <= 0 {
+		return ctx, func() {}, func() bool { return false }
+	}
+	child, cancel := context.WithCancel(ctx)
+	var fired atomic.Bool
+	done := make(chan struct{})
+	go func() {
+		defer close(done)
+		start := time.Now()
+		ticker := time.NewTicker(time.Second)
+		defer ticker.Stop()
+		last := atomic.LoadInt64(&d.completed)
+		for {
+			select {
+			case <-child.Done():
+				return
+			case <-ticker.C:
+				now := atomic.LoadInt64(&d.completed)
+				prev := last
+				last = now
+				if time.Since(start) < speedStartupGrace {
+					continue
+				}
+				if belowSpeed(prev, now, d.cfg.LowestSpeedLimit) {
+					fired.Store(true)
+					cancel()
+					return
+				}
+			}
+		}
+	}()
+	stop := func() {
+		cancel()
+		<-done
+	}
+	return child, stop, func() bool { return fired.Load() }
+}
+
 // fatal marks an error that retrying cannot fix. Unwrap exposes the wrapped
 // error so errors.Is/As traverse a fatal{} — main's exit-code mapping relies on
 // errors.Is(err, ErrNotFound) seeing through it (CONTRACT).
@@ -870,13 +1134,13 @@ func (d *Download) singleOnce(ctx context.Context, out, uri string, resumeFromDi
 	}
 }
 
-// saveInterval is how often the .got control file is rewritten so a crash can
-// resume; on a clean finish it is removed.
-const saveInterval = 60 * time.Second
-
 func (d *Download) saveLoop(ctx context.Context, out string, total int64, etag, lastmod string, segs []seg, done chan<- struct{}) {
 	defer close(done)
-	t := time.NewTicker(saveInterval)
+	interval := d.cfg.AutoSaveInterval
+	if interval <= 0 {
+		interval = 60 * time.Second // --auto-save-interval default
+	}
+	t := time.NewTicker(interval)
 	defer t.Stop()
 	for {
 		select {
@@ -907,9 +1171,13 @@ func (d *Download) request(ctx context.Context, uri, rangeHdr string) (*http.Req
 	if err != nil {
 		return nil, err
 	}
-	req.Header.Set("User-Agent", userAgent)
-	// --header sets arbitrary request headers, applied last so they can override
-	// the User-Agent (or add a Referer, Authorization, Cookie, ...) when needed.
+	req.Header.Set("User-Agent", d.cfg.UserAgent)
+	if d.cfg.Referer != "" {
+		req.Header.Set("Referer", d.cfg.Referer)
+	}
+	if d.cfg.HTTPUser != "" {
+		req.SetBasicAuth(d.cfg.HTTPUser, d.cfg.HTTPPasswd)
+	}
 	for _, h := range d.cfg.Headers {
 		if k, v, ok := strings.Cut(h, ":"); ok {
 			req.Header.Set(strings.TrimSpace(k), strings.TrimSpace(v))
@@ -918,9 +1186,33 @@ func (d *Download) request(ctx context.Context, uri, rangeHdr string) (*http.Req
 	if rangeHdr != "" {
 		req.Header.Set("Range", rangeHdr)
 	}
+	if d.jar != nil {
+		d.recordURL(req.URL)
+	}
 	return req, nil
 }
 
+// recordURL remembers a contacted URL so SaveCookies can later read back the
+// jar's cookies for that host. Duplicates are tolerated; saveCookieJar dedups.
+func (d *Download) recordURL(u *url.URL) {
+	d.mu.Lock()
+	d.seenURLs = append(d.seenURLs, u)
+	d.mu.Unlock()
+}
+
+// SaveCookies writes the client's cookie jar back to the --save-cookies file,
+// if one was configured. It is a no-op when cookies are not in use. main calls
+// it once per HTTP download on exit (cookies are saved at session end).
+func (d *Download) SaveCookies() error {
+	if d.cfg.SaveCookies == "" || d.jar == nil {
+		return nil
+	}
+	d.mu.Lock()
+	urls := append([]*url.URL{}, d.seenURLs...)
+	d.mu.Unlock()
+	return saveCookieJar(d.jar, urls, d.cfg.SaveCookies)
+}
+
 // seedSegmentsFromPrefix marks the first prefix bytes of the file as already
 // downloaded, segment by segment. A foreign partial file has no per-segment
 // metadata, so the only thing we can trust is that bytes [0,prefix) are present;

httpdl/mirror_test.go

@@ -30,24 +30,25 @@ func TestMirrorPick(t *testing.T) {
 	}
 }
 
-// TestMaxConns checks the connection ceiling: --split segment workers, floored
-// at 1. Mirrors are alternate sources, not extra connections, so they do not
-// raise the count.
+// TestMaxConns checks the connection ceiling min(split, mirrors*x), floored
+// at 1, since that decides how many segment workers fan out.
 func TestMaxConns(t *testing.T) {
-	cases := []struct{ split, mirrors, want int }{
-		{5, 1, 5}, // split is the connection count on one server
-		{16, 1, 16},
-		{5, 3, 5}, // 3 mirrors, still split connections
-		{0, 1, 1}, // floor at 1
+	cases := []struct{ split, x, mirrors, want int }{
+		{5, 1, 1, 1},  // default -x1 -s5: one connection
+		{5, 16, 1, 5}, // split is the ceiling on one server
+		{16, 16, 1, 16},
+		{5, 1, 3, 3},  // 3 mirrors * 1 per host < split
+		{16, 2, 3, 6}, // 3 mirrors * 2 per host < split
+		{0, 1, 1, 1},  // floor at 1
 	}
 	for _, c := range cases {
 		uris := make([]string, c.mirrors)
 		for i := range uris {
 			uris[i] = "http://h/x"
 		}
-		d := New(uris, Config{Split: c.split})
+		d := New(uris, Config{Split: c.split, MaxConnPerServer: c.x})
 		if d.maxConns != c.want {
-			t.Errorf("split=%d mirrors=%d: maxConns=%d, want %d", c.split, c.mirrors, d.maxConns, c.want)
+			t.Errorf("split=%d x=%d mirrors=%d: maxConns=%d, want %d", c.split, c.x, c.mirrors, d.maxConns, c.want)
 		}
 	}
 }
@@ -76,7 +77,8 @@ func TestMirrorFallback(t *testing.T) {
 	// Primary is healthy (so the probe anchors size/validators), bad is a mirror
 	// that 404s every segment it's handed.
 	d := New([]string{good.URL + "/f.bin", bad.URL + "/f.bin"}, Config{
-		Dir: dir, Out: "f.bin", Split: 4, MinSplit: 1, Tries: 1,
+		Dir: dir, Out: "f.bin", Split: 4, MaxConnPerServer: 2, MinSplit: 1,
+		Tries: 1, UserAgent: "got-test",
 	})
 	if err := d.Run(context.Background()); err != nil {
 		t.Fatalf("Run with a 404 mirror should still complete via the healthy one: %v", err)
@@ -119,7 +121,8 @@ func TestMirrorDivergentRejected(t *testing.T) {
 	dir := t.TempDir()
 	out := filepath.Join(dir, "f.bin")
 	d := New([]string{primary.URL + "/f.bin", div.URL + "/f.bin"}, Config{
-		Dir: dir, Out: "f.bin", Split: 4, MinSplit: 1, Tries: 1,
+		Dir: dir, Out: "f.bin", Split: 4, MaxConnPerServer: 2, MinSplit: 1,
+		Tries: 1, UserAgent: "got-test",
 	})
 	if err := d.Run(context.Background()); err != nil {
 		t.Fatalf("Run: %v", err)

httpdl/segment.go

@@ -16,6 +16,7 @@ type seg struct {
 }
 
 func (s *seg) length() int64      { return s.end - s.start + 1 }
+func (s *seg) endOff() int64      { return s.end }
 func (s *seg) done() bool         { return atomic.LoadInt64(&s.written) >= s.length() }
 func (s *seg) addWritten(n int64) { atomic.AddInt64(&s.written, n) }
 func (s *seg) progress() int64    { return atomic.LoadInt64(&s.written) }

httpdl/segment_test.go

@@ -201,7 +201,7 @@ func tilesCover(t *testing.T, segs []seg, total int64) {
 		if s.start != next {
 			t.Fatalf("segment gap/overlap: next byte %d, got start %d", next, s.start)
 		}
-		next = s.end + 1
+		next = s.endOff() + 1
 	}
 	if next != total {
 		t.Fatalf("segments cover %d bytes, want %d", next, total)

httpdl/single_test.go

@@ -43,9 +43,11 @@ func TestSingleShortBody(t *testing.T) {
 	out := filepath.Join(dir, "file.bin")
 
 	d := New([]string{srv.URL + "/file.bin"}, Config{
-		Dir:   dir,
-		Out:   "file.bin",
-		Tries: 1, // a single attempt so the retryable short read surfaces, not loops
+		Dir:              dir,
+		Out:              "file.bin",
+		MaxConnPerServer: 1,
+		Tries:            1, // a single attempt so the retryable short read surfaces, not loops
+		UserAgent:        "got-test",
 	})
 
 	err := d.single(context.Background(), out)
@@ -73,9 +75,11 @@ func TestSingleCompleteFullBody(t *testing.T) {
 	out := filepath.Join(dir, "file.bin")
 
 	d := New([]string{srv.URL + "/file.bin"}, Config{
-		Dir:   dir,
-		Out:   "file.bin",
-		Tries: 1,
+		Dir:              dir,
+		Out:              "file.bin",
+		MaxConnPerServer: 1,
+		Tries:            1,
+		UserAgent:        "got-test",
 	})
 
 	if err := d.single(context.Background(), out); err != nil {

httpdl/speed_test.go

@@ -0,0 +1,32 @@
+package httpdl
+
+import "testing"
+
+// TestBelowSpeed covers the speedGuard decision, including the counter-reset
+// case (item [1]): d.completed can jump backward when singleOnce rewrites it
+// with an absolute StoreInt64 and a resumed Range is answered by a 200 that
+// resets the offset to 0. A backward jump must NOT be read as a slow window, or
+// a healthy download would be false-aborted.
+func TestBelowSpeed(t *testing.T) {
+	const limit = 1000
+	cases := []struct {
+		name      string
+		prev, now int64
+		want      bool
+	}{
+		{"fast", 0, 5000, false},
+		{"exactly at limit aborts", 1000, 2000, true},
+		{"just under limit aborts", 1000, 1999, true},
+		{"just over limit ok", 1000, 2001, false},
+		{"stalled aborts", 4242, 4242, true},
+		{"counter reset is not slow", 1_000_000, 0, false},
+		{"small backward jump is not slow", 5000, 4500, false},
+	}
+	for _, c := range cases {
+		t.Run(c.name, func(t *testing.T) {
+			if got := belowSpeed(c.prev, c.now, limit); got != c.want {
+				t.Errorf("belowSpeed(%d, %d, %d) = %v; want %v", c.prev, c.now, limit, got, c.want)
+			}
+		})
+	}
+}

main.go

@@ -17,7 +17,7 @@ import (
 	"sort"
 	"strconv"
 	"strings"
-	"sync/atomic"
+	"sync"
 	"syscall"
 	"time"
 
@@ -88,19 +88,21 @@ func run(args []string) int {
 	sessionFile := opts.Str("save-session")
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	var jobsRef atomic.Pointer[[]job]
-	// publish snapshots the slice header (j is a by-value copy) and stores a
-	// pointer to it, so the signal handler can read the current jobs lock-free
-	// without racing the `jobs = append(...)` reassignment in the follow pass.
-	publish := func(j []job) { jobsRef.Store(&j) }
-	go handleSignals(cancel, sessionFile, &jobsRef)
+	// --stop: cancel everything after N seconds, exactly like a Ctrl-C, so an
+	// unattended run can't hang forever (0 = off).
+	if stop := opts.Int("stop"); stop > 0 {
+		t := time.AfterFunc(time.Duration(stop)*time.Second, cancel)
+		defer t.Stop()
+	}
+	jobsRef := &jobsHolder{}
+	go handleSignals(cancel, sessionFile, jobsRef)
 
 	eng := download.NewEngine(opts.Int("max-concurrent-downloads"))
 
 	uiCtx, uiCancel := context.WithCancel(context.Background())
 	uiDone := make(chan struct{})
 	if !opts.Bool("quiet") && !opts.Bool("dry-run") {
-		rep := progress.New(eng.Snapshot, true)
+		rep := progress.New(eng.Snapshot, opts.Bool("human-readable"))
 		go func() {
 			rep.Run(uiCtx)
 			close(uiDone)
@@ -109,12 +111,13 @@ func run(args []string) int {
 		close(uiDone)
 	}
 
-	publish(jobs)
+	jobsRef.set(jobs)
 	results := runJobs(ctx, eng, jobs)
 
-	// A .torrent fetched over HTTP becomes a BitTorrent download of its content,
-	// done as a second pass so the engine and scheduler stay simple.
-	if ctx.Err() == nil && !opts.Bool("dry-run") {
+	// --follow-torrent: a .torrent fetched over HTTP becomes a BitTorrent
+	// download of its content (on by default). Done as a second pass so the
+	// engine and scheduler stay simple.
+	if opts.Bool("follow-torrent") && ctx.Err() == nil && !opts.Bool("dry-run") {
 		if follow := followUps(jobs, btClient, btOptions(opts)); len(follow) > 0 {
 			// The engine numbers each Result by its position in the slice it was
 			// passed, so the follow pass restarts at Index 0. Offset those by the
@@ -122,7 +125,7 @@ func run(args []string) int {
 			// Index space, so the sort below restores input order deterministically.
 			nInitial := len(jobs)
 			jobs = append(jobs, follow...)
-			publish(jobs)
+			jobsRef.set(jobs)
 			followResults := runJobs(ctx, eng, follow)
 			for i := range followResults {
 				followResults[i].Index += nInitial
@@ -134,6 +137,8 @@ func run(args []string) int {
 	uiCancel()
 	<-uiDone // wait for the renderer's final frame before printing the OK/FAIL lines
 
+	saveCookies(jobs)
+
 	if sessionFile != "" {
 		if err := saveSession(sessionFile, jobs); err != nil {
 			fmt.Fprintln(os.Stderr, "got:", err)
@@ -148,6 +153,25 @@ func run(args []string) int {
 	return report(results)
 }
 
+// jobsHolder lets the signal handler reach the latest job list for a
+// best-effort session save on a forced (second-Ctrl-C) exit.
+type jobsHolder struct {
+	mu   sync.Mutex
+	jobs []job
+}
+
+func (h *jobsHolder) set(jobs []job) {
+	h.mu.Lock()
+	h.jobs = jobs
+	h.mu.Unlock()
+}
+
+func (h *jobsHolder) get() []job {
+	h.mu.Lock()
+	defer h.mu.Unlock()
+	return h.jobs
+}
+
 // job pairs a download with the source string that produced it, so we can write
 // the still-unfinished ones back to a session file.
 type job struct {
@@ -178,42 +202,52 @@ func (f *failedDownload) Stat() download.Stat {
 	return download.Stat{Name: f.name, Status: download.Errored, Total: -1}
 }
 
-// seenInfoHash records source under its torrent infohash in seen and reports
-// whether that infohash was already recorded, returning the source that first
-// claimed it. The shared client keys torrents by infohash and does not refcount,
-// so two sources naming one torrent would have the first to finish Drop it out
-// from under the other; callers fail the duplicate instead. A source whose
-// infohash can't be known without a network fetch (an HTTP URL), or that is
-// v2-only or unreadable, is never a duplicate: it isn't recorded, so it runs.
-func seenInfoHash(seen map[metainfo.Hash]string, source string, isFile bool) (first string, dup bool) {
-	h, ok := bt.SourceInfoHash(source, isFile)
+// dedupeTorrents finds torrent/magnet sources that name the same torrent as an
+// earlier source (same infohash), returning each duplicate URI mapped to the
+// earlier source it repeats. HTTP(S) URLs and any source whose infohash can't be
+// read without a network fetch are never duplicates here. The shared client keys
+// torrents by infohash and does not refcount, so build() turns each duplicate
+// into a failed download (duplicate infohash) rather than letting two jobs
+// share — and Drop — one torrent.
+func dedupeTorrents(uris []string, follow bool) map[string]string {
+	seen := map[metainfo.Hash]string{}
+	dup := map[string]string{}
+	for _, u := range uris {
+		k := uriKind(u, follow)
+		if k != kindMagnet && k != kindTorrent {
+			continue
+		}
+		h, ok := bt.SourceInfoHash(u, k == kindTorrent)
+		if !ok {
+			continue
+		}
+		if first, isDup := seen[h]; isDup {
+			dup[u] = first
+		} else {
+			seen[h] = u
+		}
+	}
+	return dup
+}
+
+// markInfoHash records the v1 infohash of the .torrent at path in seen and
+// reports whether it repeats one already seen, returning the path first recorded
+// under that infohash. Callers fail the duplicate rather than let two jobs share
+// one torrent on the client (see bt.SourceInfoHash for why that aliasing is
+// unsafe). A v2-only or unreadable infohash is never a duplicate — the dedup
+// can't see it, so it runs.
+func markInfoHash(seen map[metainfo.Hash]string, path string) (first string, dup bool) {
+	h, ok := bt.SourceInfoHash(path, true)
 	if !ok {
 		return "", false
 	}
 	if first, dup = seen[h]; dup {
 		return first, true
 	}
-	seen[h] = source
+	seen[h] = path
 	return "", false
 }
 
-// dedupeTorrents finds torrent/magnet sources that repeat an earlier source's
-// infohash, returning each duplicate URI mapped to the source it repeats.
-func dedupeTorrents(uris []string) map[string]string {
-	seen := map[metainfo.Hash]string{}
-	dup := map[string]string{}
-	for _, u := range uris {
-		k := uriKind(u)
-		if k != kindMagnet && k != kindTorrent {
-			continue
-		}
-		if first, isDup := seenInfoHash(seen, u, k == kindTorrent); isDup {
-			dup[u] = first
-		}
-	}
-	return dup
-}
-
 func build(opts *cli.Options, targets []target) ([]job, *torrent.Client, error) {
 	flat := allURIs(targets)
 	// Two sources naming the same torrent (a magnet and its own .torrent, say)
@@ -221,7 +255,7 @@ func build(opts *cli.Options, targets []target) ([]job, *torrent.Client, error)
 	// finish would Drop it out from under the other. The duplicate is reported as
 	// a failed download (duplicate infohash, exit 12); the loop below does this,
 	// so the duplicate never obtains or Drops a shared torrent.
-	dups := dedupeTorrents(flat)
+	dups := dedupeTorrents(flat, opts.Bool("follow-torrent"))
 
 	overallDL := makeLimiter(opts.Size("max-overall-download-limit"))
 	overallUL := makeLimiter(opts.Size("max-overall-upload-limit"))
@@ -239,7 +273,7 @@ func build(opts *cli.Options, targets []target) ([]job, *torrent.Client, error)
 	// it (e.g. the listen port is taken) disables BitTorrent but still lets HTTP
 	// downloads run; those torrents then report the error.
 	var client *torrent.Client
-	if needsBT(flat) {
+	if needsBT(opts, flat) {
 		c, err := bt.NewClient(btClientConfig(opts, overallDL, overallUL))
 		if err != nil {
 			fmt.Fprintln(os.Stderr, "got: bittorrent disabled:", err)
@@ -260,7 +294,7 @@ func build(opts *cli.Options, targets []target) ([]job, *torrent.Client, error)
 			continue
 		}
 		var dl download.Download
-		switch uriKind(u) {
+		switch uriKind(u, opts.Bool("follow-torrent")) {
 		case kindMagnet:
 			dl = bt.New(client, u, false, bo)
 		case kindHTTP, kindFollow:
@@ -279,15 +313,16 @@ func build(opts *cli.Options, targets []target) ([]job, *torrent.Client, error)
 }
 
 // uriKind classifies a URI by scheme into the taxonomy build() and needsBT()
-// both switch on. Scheme wins over suffix: an http URL ending in .torrent is
-// fetched over HTTP first, then followed as a torrent (kindFollow).
-func uriKind(u string) kind {
+// both switch on. Scheme wins over suffix: an http URL ending in .torrent is a
+// file to fetch over HTTP, and with --follow-torrent it becomes a torrent only
+// after the fetch (kindFollow), so it still downloads over HTTP first.
+func uriKind(u string, follow bool) kind {
 	lu := strings.ToLower(u)
 	switch {
 	case strings.HasPrefix(u, "magnet:"):
 		return kindMagnet
 	case strings.HasPrefix(u, "http://"), strings.HasPrefix(u, "https://"):
-		if strings.HasSuffix(lu, ".torrent") {
+		if follow && strings.HasSuffix(lu, ".torrent") {
 			return kindFollow
 		}
 		return kindHTTP
@@ -309,9 +344,10 @@ const (
 
 // needsBT reports whether the run will involve any torrent, so we only start a
 // client when one is actually needed.
-func needsBT(uris []string) bool {
+func needsBT(opts *cli.Options, uris []string) bool {
+	follow := opts.Bool("follow-torrent")
 	for _, u := range uris {
-		switch uriKind(u) {
+		switch uriKind(u, follow) {
 		case kindMagnet, kindTorrent, kindFollow:
 			return true
 		}
@@ -362,9 +398,11 @@ func followUps(jobs []job, client *torrent.Client, bo bt.Options) []job {
 		if _, err := bt.Files(path); err != nil {
 			continue // downloaded file is not a valid torrent
 		}
-		// build() dedupes pass-1 sources but cannot reach a not-yet-fetched HTTP
-		// .torrent, so dedupe the fetched ones here too against the same hazard.
-		if first, dup := seenInfoHash(seen, path, true); dup {
+		// Two fetched .torrent files that name the same torrent would share one
+		// torrent on the refcount-less client: the first to finish Drops it out
+		// from under the other, stranding it at 0%. build() dedupes pass-1 sources
+		// but cannot reach a not-yet-fetched HTTP .torrent, so dedupe here too.
+		if first, dup := markInfoHash(seen, path); dup {
 			out = append(out, job{source: path, dl: &failedDownload{
 				name: path,
 				err:  fmt.Errorf("%w: same torrent as %s", errDuplicate, first),
@@ -376,6 +414,19 @@ func followUps(jobs []job, client *torrent.Client, bo bt.Options) []job {
 	return out
 }
 
+// saveCookies asks each HTTP download to write its cookie jar back to the
+// --save-cookies file, persisting cookies at session end. A download with no
+// --save-cookies configured is a no-op.
+func saveCookies(jobs []job) {
+	for _, j := range jobs {
+		if h, ok := j.dl.(*httpdl.Download); ok {
+			if err := h.SaveCookies(); err != nil {
+				fmt.Fprintln(os.Stderr, "got:", err)
+			}
+		}
+	}
+}
+
 // target is one download: a single torrent/magnet/URL, or several HTTP mirror
 // URLs that serve identical bytes (uris[0] is the primary).
 type target struct{ uris []string }
@@ -390,14 +441,16 @@ func allURIs(ts []target) []string {
 	return u
 }
 
-// gatherURIs collects download targets from the command line and --input-file.
-// Plain command-line http/https URIs are grouped into ONE mirrored download by
-// default (every command-line URI names the same file); -Z/--force-sequential
-// makes each its own download. Torrents, magnets, and .torrent URLs (fetched
-// over HTTP then followed) are always one target each, since distinct torrents
-// are not mirrors of one another; --input-file groups TAB-separated URIs per line.
+// gatherURIs collects download targets from the command line, --torrent-file,
+// and --input-file. Plain command-line http/https URIs are grouped into ONE
+// mirrored download by default (every command-line URI names the same file);
+// -Z/--force-sequential makes each its own download. Torrents, magnets, and
+// .torrent URLs (fetched over HTTP then followed) are always one target each,
+// since distinct torrents are not mirrors of one another; --input-file groups
+// TAB-separated URIs per line.
 func gatherURIs(opts *cli.Options, cmdURIs []string) []target {
 	var ts []target
+	follow := opts.Bool("follow-torrent")
 	seq := opts.Bool("force-sequential")
 	var httpGroup []string
 	for _, u := range cmdURIs {
@@ -405,7 +458,7 @@ func gatherURIs(opts *cli.Options, cmdURIs []string) []target {
 		// for the same file); -Z opts out. A .torrent URL (kindFollow), like a
 		// torrent or magnet, is its own download — distinct torrents are never
 		// mirrors of one another.
-		if uriKind(u) == kindHTTP && !seq {
+		if uriKind(u, follow) == kindHTTP && !seq {
 			httpGroup = append(httpGroup, u)
 		} else {
 			ts = append(ts, target{uris: []string{u}})
@@ -414,6 +467,9 @@ func gatherURIs(opts *cli.Options, cmdURIs []string) []target {
 	if len(httpGroup) > 0 {
 		ts = append(ts, target{uris: httpGroup})
 	}
+	if tf := opts.Str("torrent-file"); tf != "" {
+		ts = append(ts, target{uris: []string{tf}})
+	}
 	if in := opts.Str("input-file"); in != "" {
 		ts = append(ts, readInputFile(in)...)
 	}
@@ -469,19 +525,38 @@ func httpConfig(opts *cli.Options, single bool, overallDL *rate.Limiter) httpdl.
 		out = opts.Str("out")
 	}
 	return httpdl.Config{
-		Dir:            opts.Str("dir"),
-		Out:            out,
-		Split:          opts.Int("split"),
-		Tries:          opts.Int("max-tries"),
-		Timeout:        time.Duration(opts.Int("timeout")) * time.Second,
-		FileAlloc:      opts.Str("file-allocation"),
-		Continue:       opts.Bool("continue"),
-		AllowOverwrite: opts.Bool("allow-overwrite"),
-		AutoRename:     opts.Bool("auto-file-renaming"),
-		Headers:        opts.List("header"),
-		OverallLimiter: overallDL,
-		Checksum:       opts.Str("checksum"),
-		DryRun:         opts.Bool("dry-run"),
+		Dir:              opts.Str("dir"),
+		Out:              out,
+		Split:            opts.Int("split"),
+		MaxConnPerServer: opts.Int("max-connection-per-server"),
+		MinSplit:         opts.Size("min-split-size"),
+		Tries:            opts.Int("max-tries"),
+		Timeout:          time.Duration(opts.Int("timeout")) * time.Second,
+		FileAlloc:        opts.Str("file-allocation"),
+		Continue:         opts.Bool("continue"),
+		AllowOverwrite:   opts.Bool("allow-overwrite"),
+		AutoRename:       opts.Bool("auto-file-renaming"),
+		Headers:          opts.List("header"),
+		UserAgent:        opts.Str("user-agent"),
+		Referer:          opts.Str("referer"),
+		Proxy:            opts.Str("all-proxy"),
+		CheckCert:        opts.Bool("check-certificate"),
+		Limit:            opts.Size("max-download-limit"),
+		OverallLimiter:   overallDL,
+		RetryWait:        time.Duration(opts.Int("retry-wait")) * time.Second,
+		AutoSaveInterval: time.Duration(opts.Int("auto-save-interval")) * time.Second,
+		ConnectTimeout:   time.Duration(opts.Int("connect-timeout")) * time.Second,
+		LoadCookies:      opts.Str("load-cookies"),
+		SaveCookies:      opts.Str("save-cookies"),
+		ConditionalGet:   opts.Bool("conditional-get"),
+		RemoteTime:       opts.Bool("remote-time"),
+		HTTPUser:         opts.Str("http-user"),
+		HTTPPasswd:       opts.Str("http-passwd"),
+		LowestSpeedLimit: opts.Size("lowest-speed-limit"),
+		Checksum:         opts.Str("checksum"),
+		DryRun:           opts.Bool("dry-run"),
+		CACert:           opts.Str("ca-certificate"),
+		DisableIPv6:      opts.Bool("disable-ipv6"),
 	}
 }
 
@@ -491,8 +566,13 @@ func btClientConfig(opts *cli.Options, overallDL, overallUL *rate.Limiter) bt.Cl
 		Dir:            opts.Str("dir"),
 		ListenPortSpec: opts.Str("listen-port"),
 		DHT:            opts.Bool("enable-dht"),
+		MaxPeers:       opts.Int("bt-max-peers"),
 		OverallDown:    overallDL,
 		OverallUp:      overallUL,
+		DownLimit:      opts.Size("max-download-limit"),
+		UpLimit:        opts.Size("max-upload-limit"),
+		UserAgent:      opts.Str("user-agent"),
+		DisableIPv6:    opts.Bool("disable-ipv6"),
 	}
 }
 
@@ -502,6 +582,8 @@ func btOptions(opts *cli.Options) bt.Options {
 		SeedTimeSet:    opts.IsSet("seed-time"),
 		SeedTime:       time.Duration(opts.Float("seed-time") * float64(time.Minute)),
 		SeedRatio:      opts.Float("seed-ratio"),
+		StopTimeout:    time.Duration(opts.Int("bt-stop-timeout")) * time.Second,
+		MetaTimeout:    time.Duration(opts.Int("bt-metadata-timeout")) * time.Second,
 		SelectFiles:    parseSelect(opts.Str("select-file")),
 		CheckIntegrity: opts.Bool("check-integrity"),
 		DryRun:         opts.Bool("dry-run"),
@@ -622,6 +704,8 @@ func exitCode(err error) int {
 		return 6
 	case errors.Is(err, httpdl.ErrNotFound):
 		return 3
+	case errors.Is(err, httpdl.ErrTooSlow):
+		return 5
 	case errors.Is(err, httpdl.ErrChecksum):
 		return 32
 	case errors.Is(err, errDuplicate):
@@ -717,18 +801,14 @@ func progressNote(s download.Stat) string {
 // TERM) cancels the graceful context so run() can wind down and save normally;
 // a second forces exit, but first writes the session best-effort so the resume
 // list survives a force-quit.
-func handleSignals(cancel context.CancelFunc, sessionFile string, jobs *atomic.Pointer[[]job]) {
+func handleSignals(cancel context.CancelFunc, sessionFile string, jobs *jobsHolder) {
 	sig := make(chan os.Signal, 2)
 	signal.Notify(sig, os.Interrupt, syscall.SIGTERM)
 	<-sig // first: cancel the graceful context
 	cancel()
 	<-sig // second: force exit
 	if sessionFile != "" {
-		var js []job // nil until the first publish; saveSession handles an empty list
-		if p := jobs.Load(); p != nil {
-			js = *p
-		}
-		if err := saveSession(sessionFile, js); err != nil {
+		if err := saveSession(sessionFile, jobs.get()); err != nil {
 			fmt.Fprintln(os.Stderr, "got:", err)
 		}
 	}

main_test.go

@@ -78,6 +78,7 @@ func TestExitCode(t *testing.T) {
 		{"refused typed", refused, 6},
 		{"refused wrapped through retries", fmt.Errorf("http://x: %w (after 5 tries)", refused), 6},
 		{"not found", fmt.Errorf("%w: http://x/y: 404 Not Found", httpdl.ErrNotFound), 3},
+		{"too slow", fmt.Errorf("http://x: %w (<= %d bytes/sec)", httpdl.ErrTooSlow, 1024), 5},
 		{"checksum", fmt.Errorf("/tmp/x: %w (want a, got b)", httpdl.ErrChecksum), 32},
 		{"duplicate", fmt.Errorf("%w: same torrent as y", errDuplicate), 12},
 		{"unknown", errors.New("disk full"), 1},
@@ -103,7 +104,7 @@ func TestDedupeTorrents(t *testing.T) {
 	c := "magnet:?xt=urn:btih:1111111111111111111111111111111111111111&dn=other"
 	web := "http://example.com/file.iso"
 
-	dup := dedupeTorrents([]string{a, web, b, c})
+	dup := dedupeTorrents([]string{a, web, b, c}, true)
 
 	// b is the only duplicate (of a); a, web and c are not duplicates.
 	if len(dup) != 1 || dup[b] != a {
@@ -143,33 +144,6 @@ func TestGatherURIsGrouping(t *testing.T) {
 	}
 }
 
-// TestHTTPConnDefault locks the parallelism default: a bare `got URL` must use
-// several connections, not one. --split is the single speed dial — it is the
-// connection count directly, defaulting to 5.
-func TestHTTPConnDefault(t *testing.T) {
-	cfg := func(args ...string) httpdl.Config {
-		res, err := cli.Parse(append([]string{"--no-conf"}, args...))
-		if err != nil {
-			t.Fatalf("parse %v: %v", args, err)
-		}
-		return httpConfig(res.Options, true, nil)
-	}
-	tests := []struct {
-		name string
-		args []string
-		want int
-	}{
-		{"bare URL uses split default", []string{"http://a/x"}, 5},
-		{"-s16 means 16", []string{"-s16", "http://a/x"}, 16},
-		{"-s1 stays single", []string{"-s1", "http://a/x"}, 1},
-	}
-	for _, tc := range tests {
-		if c := cfg(tc.args...); c.Split != tc.want {
-			t.Errorf("%s: Split = %d, want %d", tc.name, c.Split, tc.want)
-		}
-	}
-}
-
 // TestReadInputFileTAB checks the input-file grouping: TAB-separated URIs on
 // a line are mirrors of one download; a plain line is one download.
 func TestReadInputFileTAB(t *testing.T) {
@@ -237,13 +211,13 @@ func TestFollowUpInfoHashDedup(t *testing.T) {
 	}
 
 	seen := map[metainfo.Hash]string{}
-	if first, dup := seenInfoHash(seen, a, true); dup {
+	if first, dup := markInfoHash(seen, a); dup {
 		t.Fatalf("a is the first occurrence, wrongly flagged a duplicate of %s", first)
 	}
-	if first, dup := seenInfoHash(seen, b, true); !dup || first != a {
+	if first, dup := markInfoHash(seen, b); !dup || first != a {
 		t.Errorf("b should duplicate a: got first=%q dup=%v, want %q true", first, dup, a)
 	}
-	if _, dup := seenInfoHash(seen, c, true); dup {
+	if _, dup := markInfoHash(seen, c); dup {
 		t.Errorf("c is a distinct torrent, wrongly flagged a duplicate")
 	}
 }

progress/format.go

@@ -41,6 +41,12 @@ func humanSize(n int64, human bool) string {
 	return fmt.Sprintf("%.0f%ciB", val, suffix)
 }
 
+// speed formats a bytes-per-second rate. The DL:/UL: fields show the bare
+// abbreviated size with no "/s" suffix.
+func speed(bytesPerSec int64, human bool) string {
+	return humanSize(bytesPerSec, human)
+}
+
 // secfmt renders a duration as "1h2m3s", appending each unit only when it is
 // nonzero (but still showing seconds when the whole input is 0):
 // 3600s->"1h", 120s->"2m", 3720s->"1h2m". A non-positive or absurd

progress/format_test.go

@@ -53,6 +53,16 @@ func TestSecfmt(t *testing.T) {
 	}
 }
 
+func TestSpeedNoSuffix(t *testing.T) {
+	// The DL:/UL: fields show the bare abbreviated size with no "/s".
+	if got := speed(1536, true); got != "1.5KiB" {
+		t.Errorf("speed(1536,true) = %q, want %q", got, "1.5KiB")
+	}
+	if got := speed(2048, false); got != "2048B" {
+		t.Errorf("speed(2048,false) = %q, want %q", got, "2048B")
+	}
+}
+
 func TestPercent(t *testing.T) {
 	if got := percent(50, 100); got != 50 {
 		t.Errorf("percent(50,100) = %d, want 50", got)

progress/progress.go

@@ -1,8 +1,7 @@
-// Package progress renders a live status display: a summary line over one
-// aligned row per download, collapsing to the summary alone when the rows would
-// not fit. One goroutine ticks once a second, pulls a snapshot of the running
-// downloads, and derives speeds from the change since the previous tick. There
-// are no locks here: the data arrives by value through the snapshot function.
+// Package progress renders a live, single-line status display. One goroutine ticks
+// once a second, pulls a snapshot of the running downloads, and derives speeds
+// from the change since the previous tick. There are no locks here: the data
+// arrives by value through the snapshot function.
 package progress
 
 import (
@@ -10,7 +9,6 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"strconv"
 	"strings"
 	"time"
 	"unicode/utf8"
@@ -114,10 +112,13 @@ func (r *Reporter) render(final bool) {
 		r.redraw(r.block(stats), final)
 		return
 	}
-	// Not a TTY: no cursor control, so emit the summary line sparingly (and always
+	// Not a TTY: no cursor control, so emit a single line sparingly (and always
 	// the final one) to keep redirected output and logs readable.
 	var line string
-	if len(stats) > 0 {
+	switch {
+	case len(stats) == 1:
+		line = r.lineOne(stats[0])
+	case len(stats) > 1:
 		line = r.summary(stats)
 	}
 	if line != "" && (final || now.Sub(r.lastLog) >= logEvery) {
@@ -126,32 +127,61 @@ func (r *Reporter) render(final bool) {
 	}
 }
 
+func (r *Reporter) lineOne(s download.Stat) string {
+	dl, ul := r.rates(s)
+	seeding := s.Status == download.Seeding
+	var b strings.Builder
+	fmt.Fprintf(&b, "[%s ", shortName(s.Name))
+	// While seeding, report the share ratio in place of the size block and drop
+	// the DL: field; otherwise show completed/total (or bare completed).
+	if seeding {
+		fmt.Fprintf(&b, "SEED(%.1f)", ratio(s.Uploaded, s.Completed))
+	} else if s.Total > 0 {
+		fmt.Fprintf(&b, "%s/%s(%d%%)", humanSize(s.Completed, r.human), humanSize(s.Total, r.human), percent(s.Completed, s.Total))
+	} else {
+		b.WriteString(humanSize(s.Completed, r.human))
+	}
+	// CN is always shown (including HTTP); SD is shown for any torrent.
+	fmt.Fprintf(&b, " CN:%d", s.Conns)
+	if s.IsBT {
+		fmt.Fprintf(&b, " SD:%d", s.Seeders)
+	}
+	if !seeding {
+		fmt.Fprintf(&b, " DL:%s", speed(dl, r.human))
+	}
+	if seeding || ul > 0 {
+		fmt.Fprintf(&b, " UL:%s", speed(ul, r.human))
+	}
+	if !seeding && s.Total > 0 && dl > 0 {
+		fmt.Fprintf(&b, " ETA:%s", secfmt(etaDuration(s.Total-s.Completed, dl)))
+	}
+	b.WriteByte(']')
+	return b.String()
+}
+
 // nameW is the fixed rune width of the name column in the table, matching
-// elide's cap so a padded name lines the columns up.
+// shortName's cap so a padded name lines the columns up.
 const nameW = 20
 
-// block builds the lines of the live display: a summary line, the column header,
-// and one row per download — or just the one-line summary when the table would
-// not fit the window. A single download renders the same way as several.
+// block builds the lines of the live display: the single-download dashboard for
+// one download, a name/bar/speed/ETA table for several, or a one-line summary
+// when the table would not fit the window.
 func (r *Reporter) block(stats []download.Stat) []string {
-	if len(stats) == 0 {
+	switch {
+	case len(stats) == 0:
 		return nil
-	}
-	if len(stats)+3 > r.height {
-		// The block is repainted in place by moving the cursor up over it, which
-		// breaks if printing the last row reaches the screen's bottom row and
-		// scrolls the frame out from under the cursor. term height counts the row
-		// the shell prompt occupies, so a summary + header + one row each
-		// (len+2 lines) must still leave the bottom row free: fall back to the
-		// single summary line once len+2 would fill to the bottom.
+	case len(stats) == 1:
+		return []string{r.lineOne(stats[0])}
+	case len(stats)+1 > r.height: // header + one row each would overflow the screen
 		return []string{r.summary(stats)}
+	default:
+		out := make([]string, 0, len(stats)+1)
+		out = append(out, r.summary(stats))
+		for _, s := range stats {
+			out = append(out, r.tableRow(s))
+		}
+		return out
 	}
-	out := make([]string, 0, len(stats)+2)
-	out = append(out, r.summary(stats), tableHeader())
-	for _, s := range stats {
-		out = append(out, r.tableRow(s))
-	}
-	return out
 }
 
 // redraw repaints the block in place: move to the top of the previous frame,
@@ -177,134 +207,70 @@ func (r *Reporter) redraw(lines []string, final bool) {
 	}
 }
 
-// summary is the header/aggregate line: a count of downloads in each state, the
-// total down/up speed, and a stalled count when any download has gone quiet. The
-// state breakdown replaces a single "active" tally so seeding and queued
-// downloads are not lumped in with the ones actually moving bytes.
+// summary is the header/aggregate line: the active count and total down/up
+// speed, plus a stalled count when any download has gone quiet.
 func (r *Reporter) summary(stats []download.Stat) string {
 	if len(stats) == 0 {
 		return ""
 	}
 	var totDL, totUL int64
-	var downloading, seeding, queued, stalled int
+	stalled, waiting := 0, 0
 	for _, s := range stats {
 		dl, ul := r.rates(s)
 		totDL += dl
 		totUL += ul
-		switch s.Status {
-		case download.Waiting:
-			queued++
-		case download.Seeding:
-			seeding++
-		default:
-			downloading++
-			if r.isStalled(s, dl) {
-				stalled++
-			}
+		if s.Status == download.Waiting {
+			waiting++
+			continue
+		}
+		if r.isStalled(s, dl) {
+			stalled++
 		}
 	}
-	parts := []string{fmt.Sprintf("%d downloading", downloading)}
-	if seeding > 0 {
-		parts = append(parts, fmt.Sprintf("%d seeding", seeding))
+	line := fmt.Sprintf("%d active   DL:%s UL:%s", len(stats)-waiting, speed(totDL, r.human), speed(totUL, r.human))
+	if waiting > 0 {
+		line += fmt.Sprintf("  (%d waiting)", waiting)
 	}
-	if queued > 0 {
-		parts = append(parts, fmt.Sprintf("%d queued", queued))
-	}
-	line := strings.Join(parts, " · ") + fmt.Sprintf("   DL %s  UL %s", r.rateStr(totDL), r.rateStr(totUL))
 	if stalled > 0 {
 		line += fmt.Sprintf("  (%d stalled)", stalled)
 	}
 	return line
 }
 
-// tableHeader names the columns once so the rows can drop the per-field DL:/UL:
-// labels. It uses tableRow's exact format string so the headings line up over
-// their columns. SIZE is completed/total; CN is the connection/peer count and SD
-// the connected seeders — the fields that tell a stalled download (no peers)
-// from a slow one (peers, no speed).
-func tableHeader() string {
-	return fmt.Sprintf("%s  %4s  %-13s  %-8s  %3s %3s  %s", padRune("NAME", nameW), "%", "SIZE", "RATE", "CN", "SD", "ETA")
-}
-
-// tableRow renders one download as aligned columns under tableHeader:
-// "name pct size rate cn sd tail". The name is middle-elided to keep its
-// distinguishing tail; percent, rate and the peer counts are fixed-width so the
-// digits scan straight down; size is completed/total; the rate column carries
-// the download speed or a state word (seeding/queued/...), and the tail carries
-// the ETA, the share ratio while seeding, or a stalled flag.
+// tableRow renders one download as "name |bar| pct metric tail": the bar and
+// percent for progress, then the field that answers "stalled or fast" (DL speed
+// or seeding) and a tail (ETA, upload rate, or a stalled flag).
 func (r *Reporter) tableRow(s download.Stat) string {
 	dl, ul := r.rates(s)
-	rate, tail := r.rowMetric(s, dl, ul)
-	cn, sd := peerFields(s)
-	row := fmt.Sprintf("%s  %4s  %-13s  %-8s  %3s %3s  %s", padRune(elide(s.Name, nameW), nameW), pctField(s), sizeField(s, r.human), rate, cn, sd, tail)
-	// A queued row's trailing SIZE/CN/SD/ETA columns are blank; drop the trailing
-	// spaces so the line ends where its content does.
-	return strings.TrimRight(row, " ")
+	metric, tail := r.rowMetric(s, dl, ul)
+	return fmt.Sprintf("  %s  %s %s  %-9s %s", padRune(shortName(s.Name), nameW), barOf(s), pctField(s), metric, tail)
 }
 
-// sizeField is the absolute-progress column: completed/total (e.g.
-// "950MiB/5.0GiB"), just the completed bytes when the total is unknown (an HTTP
-// stream with no Content-Length, or a pre-metadata magnet), or blank for a
-// download that has not started.
-func sizeField(s download.Stat, human bool) string {
-	switch {
-	case s.Status == download.Waiting:
-		return ""
-	case s.Total > 0:
-		return humanSize(s.Completed, human) + "/" + humanSize(s.Total, human)
-	case s.Completed > 0:
-		return humanSize(s.Completed, human)
-	default:
-		return ""
-	}
-}
-
-// peerFields formats the connection (CN) and seeder (SD) columns. SD is blank
-// for HTTP, which has no seeders, and both are blank for a download with no live
-// connections (queued, done, failed) so the columns aren't noise where they
-// carry no meaning.
-func peerFields(s download.Stat) (cn, sd string) {
-	switch s.Status {
-	case download.Active, download.Seeding:
-		cn = strconv.Itoa(s.Conns)
-		if s.IsBT {
-			sd = strconv.Itoa(s.Seeders)
-		}
-	}
-	return cn, sd
-}
-
-// rowMetric returns a table row's rate column and its tail for the download's
-// state: the rate is the download speed or the state word (seeding/queued/done/
-// failed); the tail is an ETA, the share ratio while seeding (the seed-stop
-// criterion, more telling than an idle upload rate), or a "stalled" flag.
-func (r *Reporter) rowMetric(s download.Stat, dl, ul int64) (rate, tail string) {
+// rowMetric returns a table row's two trailing fields for the download's state:
+// the primary metric (DL speed, "seeding", "done", "failed") and a tail (ETA,
+// upload rate, or a "stalled" flag).
+func (r *Reporter) rowMetric(s download.Stat, dl, ul int64) (metric, tail string) {
 	switch s.Status {
 	case download.Waiting:
 		return "queued", ""
 	case download.Seeding:
-		return "seeding", fmt.Sprintf("r%.2f", ratio(s.Uploaded, s.Completed))
+		return "seeding", "UL:" + speed(ul, r.human)
 	case download.Complete:
 		return "done", ""
 	case download.Errored:
 		return "failed", ""
 	default:
-		rate = r.rateStr(dl)
+		metric = "DL:" + speed(dl, r.human)
 		switch {
 		case dl > 0 && s.Total > 0:
 			tail = secfmt(etaDuration(s.Total-s.Completed, dl))
 		case r.isStalled(s, dl):
 			tail = "stalled"
 		}
-		return rate, tail
+		return metric, tail
 	}
 }
 
-// rateStr formats a bytes/sec speed for display, e.g. "388KiB/s".
-func (r *Reporter) rateStr(bps int64) string {
-	return humanSize(bps, r.human) + "/s"
-}
-
 // maxETASeconds caps an ETA before it becomes a Duration: a near-stalled download
 // yields an astronomically large seconds value, and time.Duration(secs) *
 // time.Second would overflow int64 and wrap to a bogus tiny ETA. secfmt renders
@@ -333,6 +299,23 @@ func (r *Reporter) isStalled(s download.Stat, dl int64) bool {
 	return w.samples[len(w.samples)-1].t.Sub(w.samples[0].t) >= 4*time.Second
 }
 
+// barOf renders a fixed-width progress bar. A seeding or complete download is
+// full; an unknown total (no Content-Length, or pre-metadata) shows empty.
+func barOf(s download.Stat) string {
+	const cells = 12
+	k := 0
+	switch {
+	case s.Status == download.Seeding || s.Status == download.Complete:
+		k = cells
+	case s.Total > 0:
+		k = int(int64(cells) * s.Completed / s.Total)
+		if k > cells {
+			k = cells
+		}
+	}
+	return "|" + strings.Repeat("#", k) + strings.Repeat("-", cells-k) + "|"
+}
+
 // pctField is the percent column: a number, full for seeding/complete, or "--"
 // when the total is unknown.
 func pctField(s download.Stat) string {
@@ -411,24 +394,14 @@ func ratio(uploaded, completed int64) float64 {
 	return float64(uploaded) / float64(completed)
 }
 
-// elide shortens s to at most w runes, keeping the head and the tail joined by a
-// single "…". Download names often share a long prefix (a release group, a
-// series) and differ only at the end (an episode or volume number), so dropping
-// the middle keeps what tells two downloads apart — where a leading-only
-// truncation would collapse them to the same string. A name within w prints
-// whole. It works on runes, never bytes, so a multibyte glyph (CJK, emoji) is
-// never split.
-func elide(s string, w int) string {
-	r := []rune(s)
-	if len(r) <= w {
-		return s
+func shortName(s string) string {
+	const max = 20
+	// Truncate on runes, not bytes, so a multibyte name (CJK, emoji) is never
+	// cut mid-rune.
+	if utf8.RuneCountInString(s) > max {
+		return string([]rune(s)[:max-1]) + "~"
 	}
-	if w <= 1 {
-		return string(r[:w])
-	}
-	head := w / 2        // the w-1 kept runes split around one "…",
-	tail := w - 1 - head // head taking the extra rune when w is even
-	return string(r[:head]) + "…" + string(r[len(r)-tail:])
+	return s
 }
 
 // clampRunes limits a line to width runes (not bytes) so multibyte glyphs are

progress/progress_test.go

@@ -5,7 +5,6 @@ import (
 	"strings"
 	"testing"
 	"time"
-	"unicode/utf8"
 
 	"github.com/hanbok/got/download"
 )
@@ -78,6 +77,61 @@ func TestRatesKeyedByID(t *testing.T) {
 	}
 }
 
+// TestLineOneSeeding: while seeding, render SEED(ratio), drop DL:, keep UL:.
+func TestLineOneSeeding(t *testing.T) {
+	r := newReporter(true)
+	s := download.Stat{
+		ID: "h", Name: "f", IsBT: true, Status: download.Seeding,
+		Total: 1000, Completed: 1000, Uploaded: 1500, Conns: 3, Seeders: 2,
+	}
+	line := r.lineOne(s)
+	if !strings.Contains(line, "SEED(1.5)") {
+		t.Errorf("missing SEED(1.5): %q", line)
+	}
+	if strings.Contains(line, "DL:") {
+		t.Errorf("DL: should be dropped while seeding: %q", line)
+	}
+	if !strings.Contains(line, "UL:") {
+		t.Errorf("UL: should be kept while seeding: %q", line)
+	}
+}
+
+// TestLineOneCNSD: CN always shown; SD shown for torrents (even with 0 seeders),
+// absent for HTTP.
+func TestLineOneCNSD(t *testing.T) {
+	r := newReporter(true)
+	bt := r.lineOne(download.Stat{ID: "h", Name: "f", IsBT: true, Total: 10, Completed: 1, Conns: 4, Seeders: 0})
+	if !strings.Contains(bt, "CN:4") || !strings.Contains(bt, "SD:0") {
+		t.Errorf("torrent line missing CN/SD: %q", bt)
+	}
+	http := r.lineOne(download.Stat{ID: "h2", Name: "f", IsBT: false, Total: 10, Completed: 1, Conns: 1})
+	if !strings.Contains(http, "CN:1") {
+		t.Errorf("http line missing CN: %q", http)
+	}
+	if strings.Contains(http, "SD:") {
+		t.Errorf("http line should not show SD: %q", http)
+	}
+}
+
+func TestBarOf(t *testing.T) {
+	tests := []struct {
+		name string
+		s    download.Stat
+		want string
+	}{
+		{"empty", download.Stat{Status: download.Active, Total: 100, Completed: 0}, "|------------|"},
+		{"half", download.Stat{Status: download.Active, Total: 100, Completed: 50}, "|######------|"},
+		{"full by complete", download.Stat{Status: download.Complete}, "|############|"},
+		{"full by seeding", download.Stat{Status: download.Seeding}, "|############|"},
+		{"unknown total is empty", download.Stat{Status: download.Active, Total: -1, Completed: 9}, "|------------|"},
+	}
+	for _, tc := range tests {
+		if got := barOf(tc.s); got != tc.want {
+			t.Errorf("%s: barOf = %q, want %q", tc.name, got, tc.want)
+		}
+	}
+}
+
 func TestPctField(t *testing.T) {
 	if got := pctField(download.Stat{Status: download.Active, Total: 100, Completed: 50}); got != " 50%" {
 		t.Errorf("active 50%% = %q, want ' 50%%'", got)
@@ -90,53 +144,22 @@ func TestPctField(t *testing.T) {
 	}
 }
 
-// TestRowMetric: the rate column and trailing field per download state.
+// TestRowMetric: the two trailing fields per download state.
 func TestRowMetric(t *testing.T) {
 	r := newReporter(true)
-	if rate, tail := r.rowMetric(download.Stat{Status: download.Active, Total: 100, Completed: 50}, 10, 0); !strings.HasSuffix(rate, "/s") || tail == "" {
-		t.Errorf("active downloading: rate=%q tail=%q, want a …/s rate + an ETA", rate, tail)
+	if m, tail := r.rowMetric(download.Stat{Status: download.Active, Total: 100, Completed: 50}, 10, 0); !strings.HasPrefix(m, "DL:") || tail == "" {
+		t.Errorf("active downloading: metric=%q tail=%q, want DL:… + an ETA", m, tail)
 	}
-	if rate, tail := r.rowMetric(download.Stat{Status: download.Seeding, Completed: 1000, Uploaded: 1500}, 0, 0); rate != "seeding" || tail != "r1.50" {
-		t.Errorf("seeding: rate=%q tail=%q, want seeding + r1.50 (share ratio)", rate, tail)
+	if m, tail := r.rowMetric(download.Stat{Status: download.Seeding}, 0, 128<<10); m != "seeding" || !strings.HasPrefix(tail, "UL:") {
+		t.Errorf("seeding: metric=%q tail=%q, want seeding + UL:…", m, tail)
 	}
-	if rate, _ := r.rowMetric(download.Stat{Status: download.Complete}, 0, 0); rate != "done" {
-		t.Errorf("complete rate=%q, want done", rate)
+	if m, _ := r.rowMetric(download.Stat{Status: download.Complete}, 0, 0); m != "done" {
+		t.Errorf("complete metric=%q, want done", m)
 	}
 }
 
-// TestPeerFields: CN (connections/peers) and SD (seeders) show for active and
-// seeding downloads; SD is blank for HTTP; both blank when there are no live
-// connections (queued).
-func TestPeerFields(t *testing.T) {
-	if cn, sd := peerFields(download.Stat{Status: download.Active, IsBT: true, Conns: 18, Seeders: 4}); cn != "18" || sd != "4" {
-		t.Errorf("active torrent: cn=%q sd=%q, want 18 / 4", cn, sd)
-	}
-	if cn, sd := peerFields(download.Stat{Status: download.Active, IsBT: false, Conns: 5}); cn != "5" || sd != "" {
-		t.Errorf("active http: cn=%q sd=%q, want 5 / blank", cn, sd)
-	}
-	if cn, sd := peerFields(download.Stat{Status: download.Waiting, Conns: 0}); cn != "" || sd != "" {
-		t.Errorf("queued: cn=%q sd=%q, want blank / blank", cn, sd)
-	}
-}
-
-// TestSizeField: completed/total when the total is known, just the completed
-// bytes when it is not, and blank for a queued download.
-func TestSizeField(t *testing.T) {
-	if got := sizeField(download.Stat{Status: download.Active, Completed: 512, Total: 2048}, false); got != "512B/2048B" {
-		t.Errorf("known total = %q, want 512B/2048B", got)
-	}
-	if got := sizeField(download.Stat{Status: download.Active, Completed: 512, Total: -1}, false); got != "512B" {
-		t.Errorf("unknown total = %q, want 512B", got)
-	}
-	if got := sizeField(download.Stat{Status: download.Waiting, Total: 2048}, false); got != "" {
-		t.Errorf("queued = %q, want blank", got)
-	}
-}
-
-// TestBlockTableAndFallback: several downloads render as summary+header+rows when
-// they fit, and collapse to a single summary line when the window is too short.
-// The fallback must leave the terminal's bottom row free (the stacked-summary
-// redraw fix): summary+header+2 rows is 4 lines, so it needs height >= 5.
+// TestBlockTableAndFallback: several downloads render as header+rows when they
+// fit, and collapse to a single summary line when the window is too short.
 func TestBlockTableAndFallback(t *testing.T) {
 	r := newReporter(true)
 	stats := []download.Stat{
@@ -144,18 +167,10 @@ func TestBlockTableAndFallback(t *testing.T) {
 		{ID: "b", Name: "b", Status: download.Active, Total: 100, Completed: 10},
 	}
 	r.height = 24
-	if got := r.block(stats); len(got) != 4 { // summary + header + 2 rows
-		t.Errorf("table block = %d lines, want 4:\n%v", len(got), got)
+	if got := r.block(stats); len(got) != 3 { // header + 2 rows
+		t.Errorf("table block = %d lines, want 3:\n%v", len(got), got)
 	}
-	// A single download renders the same way as several: summary + header + 1 row.
-	if got := r.block(stats[:1]); len(got) != 3 {
-		t.Errorf("single-download block = %d lines, want 3 (summary+header+row):\n%v", len(got), got)
-	}
-	r.height = 5 // 4 lines fit with the bottom row left free
-	if got := r.block(stats); len(got) != 4 {
-		t.Errorf("just-fits block = %d lines, want 4:\n%v", len(got), got)
-	}
-	r.height = 4 // one short: would fill to the bottom row, so fall back
+	r.height = 2 // header + 2 rows = 3 > 2
 	if got := r.block(stats); len(got) != 1 {
 		t.Errorf("overflow block = %d lines, want 1 summary:\n%v", len(got), got)
 	}
@@ -176,50 +191,32 @@ func TestRenderRedraw(t *testing.T) {
 	}
 	r.render(false)
 	first := buf.String()
-	for _, want := range []string{"downloading", "seeding", "alpha", "NAME"} {
+	for _, want := range []string{"2 active", "alpha", "seeding", "|"} {
 		if !strings.Contains(first, want) {
 			t.Fatalf("first frame missing %q:\n%q", want, first)
 		}
 	}
-	if strings.Contains(first, "|") {
-		t.Errorf("first frame should carry no progress bar:\n%q", first)
-	}
 	buf.Reset()
 	r.render(false)
 	second := buf.String()
-	if !strings.Contains(second, "\x1b[3A") { // up prevLines-1 = 4-1 (summary+header+2 rows)
-		t.Errorf("second frame should move cursor up 3 lines:\n%q", second)
+	if !strings.Contains(second, "\x1b[2A") { // up prevLines-1 = 3-1
+		t.Errorf("second frame should move cursor up 2 lines:\n%q", second)
 	}
 	if !strings.Contains(second, "\x1b[J") {
 		t.Errorf("second frame should clear to end of screen:\n%q", second)
 	}
 }
 
-// TestElideKeepsTail: names sharing a long prefix but differing at the end stay
-// distinct — the failure the old leading truncation caused — and the result is
-// capped at the column width on runes with the distinguishing tail preserved.
-func TestElideKeepsTail(t *testing.T) {
-	a := elide("[Group] Long Common Series Name vol.1", nameW)
-	b := elide("[Group] Long Common Series Name vol.2", nameW)
-	if a == b {
-		t.Errorf("names differing only in the tail collapsed: %q == %q", a, b)
-	}
-	if n := utf8.RuneCountInString(a); n != nameW {
-		t.Errorf("elide rune count = %d, want %d (%q)", n, nameW, a)
-	}
-	if !strings.Contains(a, "…") {
-		t.Errorf("expected a middle ellipsis: %q", a)
-	}
-	if !strings.HasSuffix(a, "vol.1") {
-		t.Errorf("expected the distinguishing tail kept: %q", a)
-	}
-}
-
-// TestElideRune ensures CJK names are elided on runes, not bytes.
-func TestElideRune(t *testing.T) {
+// TestShortNameRune ensures CJK names are truncated on runes, not bytes.
+func TestShortNameRune(t *testing.T) {
 	name := strings.Repeat("あ", 30) // 30 runes, 90 bytes
-	if n := utf8.RuneCountInString(elide(name, nameW)); n != nameW {
-		t.Errorf("elide rune count = %d, want %d", n, nameW)
+	got := shortName(name)
+	runes := []rune(got)
+	if len(runes) != 20 {
+		t.Errorf("shortName rune count = %d, want 20", len(runes))
+	}
+	if runes[len(runes)-1] != '~' {
+		t.Errorf("expected trailing ~, got %q", got)
 	}
 }