An IBus client throws away a dead key its engine did not take — the GTK
module's own comment says so, and Qt does the same — so é and ü were
lost in every IBus application, while XIM composed them with a table of
its own. That table moves to compose.c, which both frontends now use;
xim.c is the shorter for it.
A finished sequence is text, not a key: the engine is asked to hand back
what it had pending, and the composed text follows it, so the composed
character can no longer land before the syllable typed before it.
The dictionary thread ran in imthread's own proc, so a lookup could
only start once the engine blocked, and it was a trie probe anyway; the
emoji and Hanja searches already called dictlookup directly. The
request/result channels, sequence numbers, staleness checks and the
second draw per Japanese key are gone; dictqjp fills the candidates
in place. Emit.dict and Lang.dictq only ever triggered lookups for
Vietnamese, which has no dictionary. dictlookup(Lang*, key, out, max)
returns the count. The Hanja lookup no longer pre-checks for a single
syllable; a reading either has an entry or it does not.
The hash map served a single exact-match lookup that the trie already
answers, at the price of a second container, a second file loader with
its own drift, and a Str-to-UTF-8 conversion on every chain probe. The
files are small (kanji.dict is 7.5k lines), so the trie holds both.
trieopen validates keys and each space-separated value word against Str
and reports path:line; trielookup takes the Str every caller holds and
treats a nil trie as an unloaded map; trienew/trieput exist for tests.
The overflow guards on growth, Trie.root (always 0) and the per-language
init loop written twice are gone.
ipc.c: an AF_UNIX nonblocking connect completes at once or fails with
EAGAIN, so the EINPROGRESS/poll/SO_ERROR path and the fcntl juggling
were dead; the deadline plumbing checked a clock that cannot fail and
re-tested the deadline before every transfer although only waitfd
blocks; readfield's truncation and discard loop served the unit test,
since every caller owns char[Ipcfieldmax+1]; NULL-argument checks on
in-tree encoders are gone (peer validation stays). The primary key frame
is Ipckey, not 'legacy'; ipckeysym names the keysym mapping.
srv.c: the per-connection capability and caret already lived in the
persistent Keyreq; the mirror locals and 'negotiated' flag guarded a
protocol rule no client relied on. proccreate never fails in libthread.
gtk: focus-out no longer round-trips a reset before closing the socket
that releases the engine; the caret dedup compares the packed frame;
srvconnect's preedit no-ops and the insimple flag are gone.