From 9569c2eaafc997f4d0385ab3c763c2a4c3b54ca2 Mon Sep 17 00:00:00 2001
From: Hojun-Cho <ghwns6743@gmail.com>
Date: Fri, 14 Aug 2026 01:03:13 +0900
Subject: [PATCH] tests: cover daemon endpoint collision ownership

---
 .gitignore                    |    1 +
 tests/Makefile                |    7 +-
 tests/daemon_collision_test.c | 1184 +++++++++++++++++++++++++++++++++
 3 files changed, 1191 insertions(+), 1 deletion(-)
 create mode 100644 tests/daemon_collision_test.c

diff --git a/.gitignore b/.gitignore
index dd10699..f1763f2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -4,6 +4,7 @@
 /tests/unit_test
 /tests/ibus_live_test
 /tests/ipc_live_test
+/tests/daemon_collision_test
 /xim/*.o
 /xim/strans-xim
 /xim/xim_test
diff --git a/tests/Makefile b/tests/Makefile
index 67ae5c7..a799001 100644
--- a/tests/Makefile
+++ b/tests/Makefile
@@ -9,7 +9,7 @@ IBUS_LIBS = $(shell pkg-config --libs dbus-1 xkbcommon)
 LIBS = -lthread -lbio $(FT_LIBS) $(IBUS_LIBS)
 
 PROG = unit_test
-LIVE = ibus_live_test ipc_live_test
+LIVE = ibus_live_test ipc_live_test daemon_collision_test
 TESTSRC = unit_test.c test_util.c str_test.c hash_test.c trie_test.c \
 	ko_test.c vi_test.c engine_test.c dict_test.c ipc_test.c \
 	popup_test.c font_test.c ibus_test.c server_test.c
@@ -25,6 +25,7 @@ check test: $(PROG) $(LIVE)
 	./$(PROG) $(TESTARGS)
 	./ibus_live_test ../strans ../map
 	./ipc_live_test ../strans ../map
+	./daemon_collision_test ../strans ../map
 
 $(PROG): $(OBJS)
 	$(LD) -o $@ $(OBJS) $(LIBS)
@@ -35,6 +36,10 @@ ibus_live_test: ibus_live_test.c
 ipc_live_test: ipc_live_test.c ../ipc.c ../ipc.h
 	$(HOSTCC) -std=c99 -Wall -Wextra -O2 -g -I.. -o $@ ipc_live_test.c ../ipc.c
 
+daemon_collision_test: daemon_collision_test.c ../ipc.c ../ipc.h
+	$(HOSTCC) -std=c99 -Wall -Wextra -O2 -g -I.. $(IBUS_CFLAGS) -o $@ \
+		daemon_collision_test.c ../ipc.c $(IBUS_LIBS)
+
 $(TESTOBJ): test.h ../dat.h ../fn.h ../ipc.h ../cutest/cutest.h
 engine_test.o: ../strans.c
 ibus_test.o: CFLAGS += $(IBUS_CFLAGS)
diff --git a/tests/daemon_collision_test.c b/tests/daemon_collision_test.c
new file mode 100644
index 0000000..246048f
--- /dev/null
+++ b/tests/daemon_collision_test.c
@@ -0,0 +1,1184 @@
+#define _GNU_SOURCE
+#include <dbus/dbus.h>
+#include <dirent.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <limits.h>
+#include <poll.h>
+#include <signal.h>
+#include <stdarg.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/inotify.h>
+#include <sys/socket.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <sys/un.h>
+#include <sys/wait.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "../ipc.h"
+
+enum
+{
+	Calltimeout = 4000,
+	Starttimeout = 8000,
+	Stoptimeout = 3000,
+};
+
+typedef struct Test Test;
+
+struct Test
+{
+	pid_t first;
+	pid_t second;
+	int firsterrfd;
+	int seconderrfd;
+	int notifyfd;
+	int buswd;
+	int ipcfirst;
+	int ipcnew;
+	DBusConnection *busfirst;
+	DBusConnection *busnew;
+	char root[256];
+	char runtime[320];
+	char config[320];
+	char ibus[384];
+	char bus[448];
+	char home[320];
+	char socket[384];
+	char addrfile[512];
+	char address[512];
+	char missing[384];
+	char addrcontents[2048];
+	size_t naddrcontents;
+	struct stat socketst;
+	struct stat addrst;
+	char firsterr[8192];
+	size_t nfirsterr;
+	char seconderr[8192];
+	size_t nseconderr;
+};
+
+static int
+fail(char *fmt, ...)
+{
+	va_list ap;
+
+	fprintf(stderr, "daemon_collision_test: ");
+	va_start(ap, fmt);
+	vfprintf(stderr, fmt, ap);
+	va_end(ap);
+	fputc('\n', stderr);
+	return 0;
+}
+
+static int64_t
+nowms(void)
+{
+	struct timespec ts;
+
+	if(clock_gettime(CLOCK_MONOTONIC, &ts) < 0)
+		return 0;
+	return (int64_t)ts.tv_sec * 1000 + ts.tv_nsec / 1000000;
+}
+
+static int
+leftms(int64_t deadline)
+{
+	int64_t n;
+
+	n = deadline - nowms();
+	if(n <= 0)
+		return 0;
+	if(n > 0x7fffffff)
+		return 0x7fffffff;
+	return n;
+}
+
+static int
+makedir(char *path)
+{
+	if(mkdir(path, 0700) == 0)
+		return 1;
+	return fail("mkdir %s: %s", path, strerror(errno));
+}
+
+static void
+readpipe(int fd, char *buf, size_t cap, size_t *used)
+{
+	ssize_t n;
+
+	if(fd < 0 || cap == 0)
+		return;
+	while(*used + 1 < cap){
+		n = read(fd, buf + *used, cap - *used - 1);
+		if(n > 0){
+			*used += n;
+			continue;
+		}
+		if(n < 0 && errno == EINTR)
+			continue;
+		break;
+	}
+	buf[*used] = '\0';
+}
+
+static void
+showerrors(Test *t)
+{
+	readpipe(t->firsterrfd, t->firsterr, sizeof t->firsterr,
+		&t->nfirsterr);
+	readpipe(t->seconderrfd, t->seconderr, sizeof t->seconderr,
+		&t->nseconderr);
+	if(t->nfirsterr != 0)
+		fprintf(stderr, "daemon_collision_test: first daemon stderr:\n%s",
+			t->firsterr);
+	if(t->nseconderr != 0)
+		fprintf(stderr, "daemon_collision_test: second daemon stderr:\n%s",
+			t->seconderr);
+}
+
+static int
+setup(Test *t)
+{
+	memset(t, 0, sizeof *t);
+	t->first = -1;
+	t->second = -1;
+	t->firsterrfd = -1;
+	t->seconderrfd = -1;
+	t->notifyfd = -1;
+	t->buswd = -1;
+	t->ipcfirst = -1;
+	t->ipcnew = -1;
+	snprintf(t->root, sizeof t->root, "/tmp/strans-collision.XXXXXX");
+	if(mkdtemp(t->root) == NULL){
+		t->root[0] = '\0';
+		return fail("mkdtemp: %s", strerror(errno));
+	}
+	if(snprintf(t->runtime, sizeof t->runtime, "%s/runtime", t->root)
+	   >= (int)sizeof t->runtime ||
+	   snprintf(t->config, sizeof t->config, "%s/config", t->root)
+	   >= (int)sizeof t->config ||
+	   snprintf(t->ibus, sizeof t->ibus, "%s/ibus", t->config)
+	   >= (int)sizeof t->ibus ||
+	   snprintf(t->bus, sizeof t->bus, "%s/bus", t->ibus)
+	   >= (int)sizeof t->bus ||
+	   snprintf(t->home, sizeof t->home, "%s/home", t->root)
+	   >= (int)sizeof t->home ||
+	   snprintf(t->socket, sizeof t->socket, "%s/strans.sock", t->runtime)
+	   >= (int)sizeof t->socket ||
+	   snprintf(t->missing, sizeof t->missing, "%s/missing-font.ttf", t->root)
+	   >= (int)sizeof t->missing)
+		return fail("temporary path is too long");
+	if(!makedir(t->runtime) || !makedir(t->config) || !makedir(t->ibus) ||
+	   !makedir(t->bus) || !makedir(t->home))
+		return 0;
+	t->notifyfd = inotify_init1(IN_CLOEXEC|IN_NONBLOCK);
+	if(t->notifyfd < 0)
+		return fail("inotify_init1: %s", strerror(errno));
+	t->buswd = inotify_add_watch(t->notifyfd, t->bus,
+		IN_CREATE|IN_MOVED_TO|IN_ATTRIB|IN_DELETE);
+	if(t->buswd < 0)
+		return fail("watch IBus directory: %s", strerror(errno));
+	return 1;
+}
+
+static int
+startchild(Test *t, char *program, char *mapdir, pid_t *child, int *errfd)
+{
+	int errpipe[2], fd;
+	long maxfd;
+	pid_t pid;
+
+	if(pipe2(errpipe, O_CLOEXEC|O_NONBLOCK) < 0)
+		return fail("pipe2: %s", strerror(errno));
+	pid = fork();
+	if(pid < 0){
+		close(errpipe[0]);
+		close(errpipe[1]);
+		return fail("fork: %s", strerror(errno));
+	}
+	if(pid == 0){
+		close(errpipe[0]);
+		if(dup2(errpipe[1], STDOUT_FILENO) < 0 ||
+		   dup2(errpipe[1], STDERR_FILENO) < 0)
+			_exit(126);
+		close(errpipe[1]);
+		if(close_range(3, UINT_MAX, 0) < 0){
+			maxfd = sysconf(_SC_OPEN_MAX);
+			if(maxfd < 0)
+				maxfd = 1024;
+			for(fd = 3; fd < maxfd; fd++)
+				close(fd);
+		}
+		if(setenv("XDG_RUNTIME_DIR", t->runtime, 1) < 0 ||
+		   setenv("XDG_CONFIG_HOME", t->config, 1) < 0 ||
+		   setenv("HOME", t->home, 1) < 0 || unsetenv("DISPLAY") < 0 ||
+		   unsetenv("DBUS_SESSION_BUS_ADDRESS") < 0 ||
+		   unsetenv("IBUS_ADDRESS") < 0){
+			dprintf(STDERR_FILENO, "set daemon environment: %s\n",
+				strerror(errno));
+			_exit(126);
+		}
+		execl(program, program, mapdir, t->missing, (char*)0);
+		dprintf(STDERR_FILENO, "exec %s: %s\n", program, strerror(errno));
+		_exit(127);
+	}
+	close(errpipe[1]);
+	*child = pid;
+	*errfd = errpipe[0];
+	return 1;
+}
+
+static int
+drainnotify(Test *t, int trackbus, int *changed)
+{
+	char buf[4096];
+	struct inotify_event *ev;
+	ssize_t n;
+	size_t off;
+
+	for(;;){
+		n = read(t->notifyfd, buf, sizeof buf);
+		if(n < 0 && errno == EINTR)
+			continue;
+		if(n < 0 && errno == EAGAIN)
+			return 1;
+		if(n < 0)
+			return fail("read endpoint watches: %s", strerror(errno));
+		if(n == 0)
+			return 1;
+		for(off = 0; off + sizeof *ev <= (size_t)n;
+		   off += sizeof *ev + ev->len){
+			ev = (struct inotify_event*)(buf + off);
+			if(off + sizeof *ev + ev->len > (size_t)n)
+				return fail("truncated inotify event");
+			if(ev->mask & IN_Q_OVERFLOW)
+				return fail("endpoint watch queue overflowed");
+			if(trackbus && changed != NULL && ev->wd == t->buswd &&
+			   ev->len != 0 &&
+			   (ev->mask & (IN_CREATE|IN_MOVED_TO|IN_DELETE|IN_ATTRIB))){
+				*changed = 1;
+			}
+		}
+	}
+}
+
+static int
+findaddress(Test *t)
+{
+	DIR *dir;
+	struct dirent *de;
+	int count, ok;
+
+	dir = opendir(t->bus);
+	if(dir == NULL){
+		fail("open IBus directory %s: %s", t->bus, strerror(errno));
+		return -1;
+	}
+	count = 0;
+	ok = 1;
+	errno = 0;
+	while((de = readdir(dir)) != NULL){
+		if(strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0 ||
+		   strstr(de->d_name, ".tmp.") != NULL)
+			continue;
+		count++;
+		if(snprintf(t->addrfile, sizeof t->addrfile, "%s/%s", t->bus,
+		   de->d_name) >= (int)sizeof t->addrfile){
+			fail("IBus address path is too long");
+			ok = 0;
+			break;
+		}
+	}
+	if(errno != 0){
+		fail("read IBus directory %s: %s", t->bus, strerror(errno));
+		ok = 0;
+	}
+	if(closedir(dir) < 0){
+		fail("close IBus directory %s: %s", t->bus, strerror(errno));
+		ok = 0;
+	}
+	if(!ok)
+		return -1;
+	if(count > 1){
+		fail("found %d IBus address files", count);
+		return -1;
+	}
+	return count;
+}
+
+static int
+readfile(char *path, char *buf, size_t cap, size_t *nread)
+{
+	struct stat st;
+	ssize_t n;
+	size_t off;
+	char extra;
+	int fd, ok;
+
+	fd = open(path, O_RDONLY|O_CLOEXEC);
+	if(fd < 0)
+		return fail("open %s: %s", path, strerror(errno));
+	ok = 0;
+	if(fstat(fd, &st) < 0){
+		fail("stat open address file %s: %s", path, strerror(errno));
+		goto out;
+	}
+	if(st.st_size < 0 || (uintmax_t)st.st_size >= cap){
+		fail("address file %s is too large", path);
+		goto out;
+	}
+	off = 0;
+	while(off < (size_t)st.st_size){
+		n = read(fd, buf + off, (size_t)st.st_size - off);
+		if(n < 0 && errno == EINTR)
+			continue;
+		if(n <= 0){
+			fail("read %s: %s", path,
+				n == 0 ? "unexpected EOF" : strerror(errno));
+			goto out;
+		}
+		off += n;
+	}
+	do
+		n = read(fd, &extra, 1);
+	while(n < 0 && errno == EINTR);
+	if(n != 0){
+		fail("address file %s changed while being read", path);
+		goto out;
+	}
+	buf[off] = '\0';
+	*nread = off;
+	ok = 1;
+out:
+	if(close(fd) < 0){
+		fail("close %s: %s", path, strerror(errno));
+		ok = 0;
+	}
+	return ok;
+}
+
+static int
+parseaddress(char *contents, size_t ncontents, char *address, size_t naddress,
+	pid_t expected)
+{
+	char found[512];
+	long pid;
+	int consumed;
+
+	consumed = -1;
+	if(strlen(contents) != ncontents ||
+	   sscanf(contents, "IBUS_ADDRESS=%511[^\n]\nIBUS_DAEMON_PID=%ld\n%n",
+	   found, &pid, &consumed) != 2 || consumed != (int)ncontents)
+		return fail("invalid IBus address file contents");
+	if(pid != expected)
+		return fail("IBus address PID %ld, expected %ld", pid,
+			(long)expected);
+	if(snprintf(address, naddress, "%s", found) >= (int)naddress)
+		return fail("private IBus address is too long");
+	return 1;
+}
+
+static int
+childalive(pid_t *pid, char *which)
+{
+	int n, status;
+
+	do
+		n = waitpid(*pid, &status, WNOHANG);
+	while(n < 0 && errno == EINTR);
+	if(n == 0)
+		return 1;
+	if(n == *pid){
+		fail("%s daemon exited unexpectedly with wait status %#x", which,
+			status);
+		*pid = -1;
+		return 0;
+	}
+	if(n < 0){
+		fail("check %s daemon %ld: %s", which, (long)*pid,
+			strerror(errno));
+		if(errno == ECHILD)
+			*pid = -1;
+		return 0;
+	}
+	return fail("waitpid returned the wrong %s child", which);
+}
+
+static int
+waitready(Test *t)
+{
+	struct pollfd pfd[2];
+	struct stat st;
+	char contents[2048], address[512];
+	size_t ncontents;
+	int n, count, socketready, timeout;
+	int64_t deadline;
+
+	deadline = nowms() + Starttimeout;
+	for(;;){
+		socketready = lstat(t->socket, &st) == 0 && S_ISSOCK(st.st_mode) &&
+			(st.st_mode & 0777) == 0600;
+		count = findaddress(t);
+		if(count < 0)
+			return 0;
+		if(socketready && count == 1 &&
+		   readfile(t->addrfile, contents, sizeof contents, &ncontents) &&
+		   parseaddress(contents, ncontents, address, sizeof address,
+		   t->first))
+			return 1;
+		if(!childalive(&t->first, "first"))
+			return 0;
+		timeout = leftms(deadline);
+		if(timeout == 0)
+			return fail("timed out waiting for both daemon endpoints");
+		pfd[0].fd = t->notifyfd;
+		pfd[0].events = POLLIN;
+		pfd[0].revents = 0;
+		pfd[1].fd = t->firsterrfd;
+		pfd[1].events = POLLIN|POLLHUP;
+		pfd[1].revents = 0;
+		n = poll(pfd, 2, timeout);
+		if(n < 0 && errno == EINTR)
+			continue;
+		if(n < 0)
+			return fail("poll daemon readiness: %s", strerror(errno));
+		if(pfd[1].revents != 0)
+			readpipe(t->firsterrfd, t->firsterr, sizeof t->firsterr,
+				&t->nfirsterr);
+		if((pfd[0].revents & POLLIN) && !drainnotify(t, 0, NULL))
+			return 0;
+	}
+}
+
+static int
+snapshot(Test *t)
+{
+	if(lstat(t->socket, &t->socketst) < 0)
+		return fail("stat first IPC socket: %s", strerror(errno));
+	if(!S_ISSOCK(t->socketst.st_mode) || (t->socketst.st_mode & 0777) != 0600)
+		return fail("first IPC endpoint is not a protected socket");
+	if(lstat(t->addrfile, &t->addrst) < 0)
+		return fail("stat first IBus address file: %s", strerror(errno));
+	if(!S_ISREG(t->addrst.st_mode) || (t->addrst.st_mode & 0777) != 0600)
+		return fail("first IBus address is not a protected regular file");
+	if(!readfile(t->addrfile, t->addrcontents, sizeof t->addrcontents,
+	   &t->naddrcontents))
+		return 0;
+	return parseaddress(t->addrcontents, t->naddrcontents, t->address,
+		sizeof t->address, t->first);
+}
+
+static int
+connectsocket(char *path, int64_t deadline)
+{
+	struct sockaddr_un addr;
+	struct pollfd pfd;
+	socklen_t nerr;
+	int err, fd, flags, n;
+
+	memset(&addr, 0, sizeof addr);
+	addr.sun_family = AF_UNIX;
+	if(snprintf(addr.sun_path, sizeof addr.sun_path, "%s", path)
+	   >= (int)sizeof addr.sun_path){
+		errno = ENAMETOOLONG;
+		return -1;
+	}
+	fd = socket(AF_UNIX, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
+	if(fd < 0)
+		return -1;
+	if(connect(fd, (struct sockaddr*)&addr, sizeof addr) < 0 &&
+	   errno != EINPROGRESS){
+		err = errno;
+		close(fd);
+		errno = err;
+		return -1;
+	}
+	for(;;){
+		n = leftms(deadline);
+		if(n == 0){
+			close(fd);
+			errno = ETIMEDOUT;
+			return -1;
+		}
+		pfd.fd = fd;
+		pfd.events = POLLOUT;
+		pfd.revents = 0;
+		n = poll(&pfd, 1, n);
+		if(n < 0 && errno == EINTR)
+			continue;
+		if(n <= 0){
+			err = n == 0 ? ETIMEDOUT : errno;
+			close(fd);
+			errno = err;
+			return -1;
+		}
+		break;
+	}
+	err = 0;
+	nerr = sizeof err;
+	if(getsockopt(fd, SOL_SOCKET, SO_ERROR, &err, &nerr) < 0 || err != 0){
+		if(err == 0)
+			err = errno;
+		close(fd);
+		errno = err;
+		return -1;
+	}
+	flags = fcntl(fd, F_GETFL);
+	if(flags < 0 || fcntl(fd, F_SETFL, flags & ~O_NONBLOCK) < 0){
+		err = errno;
+		close(fd);
+		errno = err;
+		return -1;
+	}
+	return fd;
+}
+
+static int
+readuntil(int fd, void *buf, size_t n, int64_t deadline)
+{
+	struct pollfd pfd;
+	unsigned char *p;
+	ssize_t r;
+	int timeout;
+
+	p = buf;
+	while(n > 0){
+		timeout = leftms(deadline);
+		if(timeout == 0){
+			errno = ETIMEDOUT;
+			return -1;
+		}
+		pfd.fd = fd;
+		pfd.events = POLLIN;
+		pfd.revents = 0;
+		r = poll(&pfd, 1, timeout);
+		if(r < 0 && errno == EINTR)
+			continue;
+		if(r <= 0){
+			if(r == 0)
+				errno = ETIMEDOUT;
+			return -1;
+		}
+		r = recv(fd, p, n, 0);
+		if(r < 0 && errno == EINTR)
+			continue;
+		if(r <= 0){
+			if(r == 0)
+				errno = ECONNRESET;
+			return -1;
+		}
+		p += r;
+		n -= r;
+	}
+	return 0;
+}
+
+static int
+ipcprobe(int fd, char *where)
+{
+	unsigned char req[Ipcreqsz], reply[Ipcresphdrsz+Ipclensz];
+
+	ipcpackreq(req, 1, 0, Kmodfirst);
+	if(ipcsend(fd, req, sizeof req) < 0)
+		return fail("send %s IPC request: %s", where, strerror(errno));
+	if(readuntil(fd, reply, sizeof reply, nowms() + Calltimeout) < 0)
+		return fail("read %s IPC response: %s", where, strerror(errno));
+	if(reply[0] != 0 || reply[1] != 0 || reply[2] != 0 ||
+	   reply[3] != 0 || reply[4] != 0)
+		return fail("%s IPC response was not an empty modifier reply", where);
+	return 1;
+}
+
+static void
+closebus(DBusConnection **conn)
+{
+	if(*conn == NULL)
+		return;
+	dbus_connection_close(*conn);
+	dbus_connection_unref(*conn);
+	*conn = NULL;
+}
+
+static DBusMessage*
+sendcall(DBusConnection *conn, DBusMessage *m, char *where)
+{
+	DBusMessage *reply;
+	DBusPendingCall *pending;
+	int timeout;
+	int64_t deadline;
+
+	if(m == NULL){
+		fail("allocate %s call", where);
+		return NULL;
+	}
+	pending = NULL;
+	if(!dbus_connection_send_with_reply(conn, m, &pending, Calltimeout) ||
+	   pending == NULL){
+		dbus_message_unref(m);
+		fail("queue %s call", where);
+		return NULL;
+	}
+	dbus_message_unref(m);
+	deadline = nowms() + Calltimeout;
+	while(!dbus_pending_call_get_completed(pending)){
+		timeout = leftms(deadline);
+		if(timeout == 0){
+			fail("timed out waiting for %s", where);
+			goto fail;
+		}
+		if(!dbus_connection_read_write_dispatch(conn, timeout)){
+			fail("connection closed waiting for %s", where);
+			goto fail;
+		}
+	}
+	reply = dbus_pending_call_steal_reply(pending);
+	dbus_pending_call_unref(pending);
+	if(reply == NULL)
+		fail("%s completed without a reply", where);
+	return reply;
+fail:
+	dbus_pending_call_cancel(pending);
+	dbus_pending_call_unref(pending);
+	return NULL;
+}
+
+static DBusConnection*
+openbus(char *address)
+{
+	DBusConnection *conn;
+	DBusError err;
+
+	dbus_error_init(&err);
+	conn = dbus_connection_open_private(address, &err);
+	if(conn == NULL){
+		fail("open private IBus connection: %s",
+			err.message != NULL ? err.message : "D-Bus error");
+		dbus_error_free(&err);
+		return NULL;
+	}
+	dbus_error_free(&err);
+	dbus_connection_set_exit_on_disconnect(conn, FALSE);
+	return conn;
+}
+
+static int
+hello(DBusConnection *conn, char *name, size_t nname, char *where)
+{
+	DBusMessage *m, *reply;
+	DBusError err;
+	const char *s;
+
+	m = dbus_message_new_method_call("org.freedesktop.DBus",
+		"/org/freedesktop/DBus", "org.freedesktop.DBus", "Hello");
+	reply = sendcall(conn, m, where);
+	if(reply == NULL)
+		return 0;
+	dbus_error_init(&err);
+	if(!dbus_message_has_signature(reply, "s") ||
+	   !dbus_message_get_args(reply, &err, DBUS_TYPE_STRING, &s,
+	   DBUS_TYPE_INVALID)){
+		dbus_message_unref(reply);
+		dbus_error_free(&err);
+		return fail("%s returned an invalid Hello reply", where);
+	}
+	if(snprintf(name, nname, "%s", s) >= (int)nname){
+		dbus_error_free(&err);
+		dbus_message_unref(reply);
+		return fail("%s Hello name is too long", where);
+	}
+	dbus_error_free(&err);
+	dbus_message_unref(reply);
+	return name[0] == ':' || fail("%s returned invalid Hello name %s",
+		where, name);
+}
+
+static int
+createcontext(DBusConnection *conn, char *path, size_t npath, char *where)
+{
+	DBusMessage *m, *reply;
+	DBusError err;
+	const char *client, *p;
+
+	client = "daemon-collision-test";
+	m = dbus_message_new_method_call("org.freedesktop.IBus",
+		"/org/freedesktop/IBus", "org.freedesktop.IBus",
+		"CreateInputContext");
+	if(m == NULL || !dbus_message_append_args(m, DBUS_TYPE_STRING, &client,
+	   DBUS_TYPE_INVALID)){
+		if(m != NULL)
+			dbus_message_unref(m);
+		return fail("build %s CreateInputContext call", where);
+	}
+	reply = sendcall(conn, m, where);
+	if(reply == NULL)
+		return 0;
+	dbus_error_init(&err);
+	if(!dbus_message_has_signature(reply, "o") ||
+	   !dbus_message_get_args(reply, &err, DBUS_TYPE_OBJECT_PATH, &p,
+	   DBUS_TYPE_INVALID)){
+		dbus_message_unref(reply);
+		dbus_error_free(&err);
+		return fail("%s returned an invalid context reply", where);
+	}
+	if(snprintf(path, npath, "%s", p) >= (int)npath){
+		dbus_error_free(&err);
+		dbus_message_unref(reply);
+		return fail("%s context path is too long", where);
+	}
+	dbus_error_free(&err);
+	dbus_message_unref(reply);
+	return path[0] == '/' || fail("%s returned invalid context path %s",
+		where, path);
+}
+
+static int
+killowned(pid_t *pid, int *status)
+{
+	int n, ok;
+
+	ok = 1;
+	if(kill(*pid, SIGKILL) < 0 && errno != ESRCH){
+		fail("kill -9 %ld: %s", (long)*pid, strerror(errno));
+		ok = 0;
+	}
+	do
+		n = waitpid(*pid, status, 0);
+	while(n < 0 && errno == EINTR);
+	if(n != *pid){
+		fail("reap %ld after SIGKILL: %s", (long)*pid,
+			n < 0 ? strerror(errno) : "wrong child");
+		ok = 0;
+	}else
+		*pid = -1;
+	return ok;
+}
+
+static int
+waitsecond(Test *t, int *changed)
+{
+	struct pollfd pfd[2];
+	int n, status, timeout;
+	int64_t deadline;
+
+	deadline = nowms() + Starttimeout;
+	for(;;){
+		do
+			n = waitpid(t->second, &status, WNOHANG);
+		while(n < 0 && errno == EINTR);
+		if(n == t->second){
+			t->second = -1;
+			readpipe(t->seconderrfd, t->seconderr, sizeof t->seconderr,
+				&t->nseconderr);
+			if(!drainnotify(t, 1, changed))
+				return 0;
+			if(!WIFEXITED(status) || WEXITSTATUS(status) == 0)
+				return fail("second daemon did not exit unsuccessfully: %#x",
+					status);
+			if(strstr(t->seconderr, "IPC endpoint is already in use") == NULL)
+				return fail("second daemon did not report the IPC collision");
+			return 1;
+		}
+		if(n < 0){
+			fail("waitpid second daemon %ld: %s", (long)t->second,
+				strerror(errno));
+			if(errno == ECHILD)
+				t->second = -1;
+			return 0;
+		}
+		if(!childalive(&t->first, "first"))
+			return 0;
+		timeout = leftms(deadline);
+		if(timeout == 0){
+			fail("second daemon did not exit after the endpoint collision");
+			if(!killowned(&t->second, &status))
+				return 0;
+			return 0;
+		}
+		pfd[0].fd = t->notifyfd;
+		pfd[0].events = POLLIN;
+		pfd[0].revents = 0;
+		pfd[1].fd = t->seconderrfd;
+		pfd[1].events = POLLIN|POLLHUP;
+		pfd[1].revents = 0;
+		n = poll(pfd, 2, timeout);
+		if(n < 0 && errno == EINTR)
+			continue;
+		if(n < 0)
+			return fail("poll second daemon: %s", strerror(errno));
+		if(pfd[1].revents != 0)
+			readpipe(t->seconderrfd, t->seconderr, sizeof t->seconderr,
+				&t->nseconderr);
+		if((pfd[0].revents & POLLIN) &&
+		   !drainnotify(t, 1, changed))
+			return 0;
+	}
+}
+
+static int
+checksocket(Test *t)
+{
+	struct stat st;
+
+	if(lstat(t->socket, &st) < 0)
+		return fail("first IPC socket disappeared: %s", strerror(errno));
+	if(!S_ISSOCK(st.st_mode) || st.st_mode != t->socketst.st_mode ||
+	   st.st_dev != t->socketst.st_dev || st.st_ino != t->socketst.st_ino)
+		return fail("first IPC socket identity or protection changed");
+	return 1;
+}
+
+static int
+checkaddress(Test *t)
+{
+	struct stat st;
+	char contents[2048], address[512];
+	size_t ncontents;
+
+	if(lstat(t->addrfile, &st) < 0)
+		return fail("first IBus address file disappeared: %s",
+			strerror(errno));
+	if(st.st_mode != t->addrst.st_mode || st.st_dev != t->addrst.st_dev ||
+	   st.st_ino != t->addrst.st_ino)
+		return fail("first IBus address file identity or protection changed");
+	if(!readfile(t->addrfile, contents, sizeof contents, &ncontents))
+		return 0;
+	if(ncontents != t->naddrcontents ||
+	   memcmp(contents, t->addrcontents, ncontents) != 0)
+		return fail("first IBus address file contents changed");
+	if(!parseaddress(contents, ncontents, address, sizeof address, t->first))
+		return 0;
+	return strcmp(address, t->address) == 0 ||
+		fail("first private IBus address changed");
+}
+
+static int
+onlyaddress(Test *t)
+{
+	DIR *dir;
+	struct dirent *de;
+	char expected[512];
+	char *base;
+	int count, ok;
+
+	base = strrchr(t->addrfile, '/');
+	if(base == NULL)
+		return fail("invalid recorded IBus address path");
+	if(snprintf(expected, sizeof expected, "%s", base + 1)
+	   >= (int)sizeof expected)
+		return fail("recorded IBus address name is too long");
+	dir = opendir(t->bus);
+	if(dir == NULL)
+		return fail("open IBus directory after collision: %s",
+			strerror(errno));
+	count = 0;
+	ok = 1;
+	errno = 0;
+	while((de = readdir(dir)) != NULL){
+		if(strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0)
+			continue;
+		count++;
+		if(strcmp(de->d_name, expected) != 0){
+			fail("unexpected IBus directory entry %s", de->d_name);
+			ok = 0;
+		}
+	}
+	if(errno != 0){
+		fail("read IBus directory after collision: %s", strerror(errno));
+		ok = 0;
+	}
+	if(closedir(dir) < 0){
+		fail("close IBus directory after collision: %s", strerror(errno));
+		ok = 0;
+	}
+	if(count != 1){
+		fail("IBus directory contains %d entries after collision", count);
+		ok = 0;
+	}
+	return ok;
+}
+
+static int
+runcollision(Test *t, char *program, char *mapdir)
+{
+	char firsthello[32], newhello[32];
+	char firstpath[96], persistentpath[96], newpath[96];
+	int changed;
+
+	if(!startchild(t, program, mapdir, &t->first, &t->firsterrfd) ||
+	   !waitready(t) || !snapshot(t))
+		return 0;
+	t->ipcfirst = connectsocket(t->socket, nowms() + Calltimeout);
+	if(t->ipcfirst < 0)
+		return fail("connect persistent IPC client: %s", strerror(errno));
+	if(!ipcprobe(t->ipcfirst, "persistent pre-collision"))
+		return 0;
+	t->busfirst = openbus(t->address);
+	if(t->busfirst == NULL ||
+	   !hello(t->busfirst, firsthello, sizeof firsthello,
+	   "persistent pre-collision Hello") ||
+	   !createcontext(t->busfirst, firstpath, sizeof firstpath,
+	   "persistent pre-collision context"))
+		return 0;
+	if(!drainnotify(t, 0, NULL))
+		return 0;
+	changed = 0;
+	if(!startchild(t, program, mapdir, &t->second, &t->seconderrfd) ||
+	   !waitsecond(t, &changed))
+		return 0;
+	if(changed)
+		return fail("second daemon touched the first IBus address directory");
+	if(!childalive(&t->first, "first") || !checksocket(t) ||
+	   !checkaddress(t) || !onlyaddress(t))
+		return 0;
+	if(!ipcprobe(t->ipcfirst, "persistent post-collision"))
+		return 0;
+	if(!createcontext(t->busfirst, persistentpath, sizeof persistentpath,
+	   "persistent post-collision context"))
+		return 0;
+	t->ipcnew = connectsocket(t->socket, nowms() + Calltimeout);
+	if(t->ipcnew < 0)
+		return fail("connect new IPC client after collision: %s",
+			strerror(errno));
+	if(!ipcprobe(t->ipcnew, "new post-collision"))
+		return 0;
+	t->busnew = openbus(t->address);
+	if(t->busnew == NULL ||
+	   !hello(t->busnew, newhello, sizeof newhello,
+	   "new post-collision Hello") ||
+	   !createcontext(t->busnew, newpath, sizeof newpath,
+	   "new post-collision context"))
+		return 0;
+	return childalive(&t->first, "first");
+}
+
+static int
+stopfirst(Test *t)
+{
+	struct pollfd pfd;
+	int n, ok, reaped, status;
+	int64_t deadline;
+
+	if(t->first <= 0)
+		return 1;
+	ok = 1;
+	if(!childalive(&t->first, "first"))
+		return 0;
+	if(kill(t->first, SIGTERM) < 0){
+		fail("kill first daemon %ld: %s", (long)t->first, strerror(errno));
+		ok = 0;
+	}
+	reaped = 0;
+	deadline = nowms() + Stoptimeout;
+	while(t->first > 0){
+		n = waitpid(t->first, &status, WNOHANG);
+		if(n == t->first){
+			reaped = 1;
+			t->first = -1;
+			break;
+		}
+		if(n < 0 && errno == EINTR)
+			continue;
+		if(n < 0){
+			fail("waitpid first daemon %ld: %s", (long)t->first,
+				strerror(errno));
+			if(errno == ECHILD)
+				t->first = -1;
+			ok = 0;
+			break;
+		}
+		n = leftms(deadline);
+		if(n == 0){
+			fail("first daemon %ld did not stop after SIGTERM",
+				(long)t->first);
+			ok = 0;
+			if(!killowned(&t->first, &status))
+				ok = 0;
+			break;
+		}
+		pfd.fd = t->firsterrfd;
+		pfd.events = POLLIN|POLLHUP;
+		pfd.revents = 0;
+		if(poll(&pfd, 1, n) < 0 && errno != EINTR){
+			fail("poll first daemon termination: %s", strerror(errno));
+			ok = 0;
+			if(!killowned(&t->first, &status))
+				ok = 0;
+			break;
+		}
+		readpipe(t->firsterrfd, t->firsterr, sizeof t->firsterr,
+			&t->nfirsterr);
+	}
+	if(reaped &&
+	   !((WIFSIGNALED(status) && WTERMSIG(status) == SIGTERM) ||
+	   (WIFEXITED(status) && WEXITSTATUS(status) == 1))){
+		fail("first daemon exited with unexpected wait status %#x", status);
+		ok = 0;
+	}
+	return ok;
+}
+
+static int
+clearbus(Test *t)
+{
+	DIR *dir;
+	struct dirent *de;
+	char path[576];
+	int ok;
+
+	dir = opendir(t->bus);
+	if(dir == NULL)
+		return errno == ENOENT || fail("open cleanup directory %s: %s",
+			t->bus, strerror(errno));
+	ok = 1;
+	errno = 0;
+	while((de = readdir(dir)) != NULL){
+		if(strcmp(de->d_name, ".") == 0 || strcmp(de->d_name, "..") == 0)
+			continue;
+		if(snprintf(path, sizeof path, "%s/%s", t->bus, de->d_name)
+		   >= (int)sizeof path){
+			fail("cleanup path is too long: %s", de->d_name);
+			ok = 0;
+			continue;
+		}
+		if(unlink(path) < 0 && errno != ENOENT){
+			fail("remove IBus cleanup file %s: %s", de->d_name,
+				strerror(errno));
+			ok = 0;
+		}
+		errno = 0;
+	}
+	if(errno != 0){
+		fail("read cleanup directory %s: %s", t->bus, strerror(errno));
+		ok = 0;
+	}
+	if(closedir(dir) < 0){
+		fail("close cleanup directory %s: %s", t->bus, strerror(errno));
+		ok = 0;
+	}
+	return ok;
+}
+
+static int
+rmdirknown(char *path)
+{
+	if(path[0] == '\0' || rmdir(path) == 0 || errno == ENOENT)
+		return 1;
+	return fail("rmdir %s: %s", path, strerror(errno));
+}
+
+static int
+cleanup(Test *t)
+{
+	int n, ok, status;
+
+	ok = 1;
+	closebus(&t->busnew);
+	closebus(&t->busfirst);
+	if(t->ipcnew >= 0){
+		if(close(t->ipcnew) < 0){
+			fail("close new IPC client: %s", strerror(errno));
+			ok = 0;
+		}
+		t->ipcnew = -1;
+	}
+	if(t->ipcfirst >= 0){
+		if(close(t->ipcfirst) < 0){
+			fail("close persistent IPC client: %s", strerror(errno));
+			ok = 0;
+		}
+		t->ipcfirst = -1;
+	}
+	if(t->second > 0){
+		do
+			n = waitpid(t->second, &status, WNOHANG);
+		while(n < 0 && errno == EINTR);
+		if(n == t->second)
+			t->second = -1;
+		else if(n == 0){
+			fail("second daemon still running during cleanup");
+			ok = 0;
+			if(!killowned(&t->second, &status))
+				ok = 0;
+		}else{
+			fail("check second daemon during cleanup: %s", strerror(errno));
+			ok = 0;
+			if(errno == ECHILD)
+				t->second = -1;
+			else if(!killowned(&t->second, &status))
+				ok = 0;
+		}
+	}
+	if(!stopfirst(t))
+		ok = 0;
+	readpipe(t->firsterrfd, t->firsterr, sizeof t->firsterr,
+		&t->nfirsterr);
+	readpipe(t->seconderrfd, t->seconderr, sizeof t->seconderr,
+		&t->nseconderr);
+	if(t->firsterrfd >= 0){
+		if(close(t->firsterrfd) < 0){
+			fail("close first daemon stderr: %s", strerror(errno));
+			ok = 0;
+		}
+		t->firsterrfd = -1;
+	}
+	if(t->seconderrfd >= 0){
+		if(close(t->seconderrfd) < 0){
+			fail("close second daemon stderr: %s", strerror(errno));
+			ok = 0;
+		}
+		t->seconderrfd = -1;
+	}
+	if(t->notifyfd >= 0){
+		if(t->buswd >= 0 &&
+		   inotify_rm_watch(t->notifyfd, t->buswd) < 0 && errno != EINVAL){
+			fail("remove IBus watch: %s", strerror(errno));
+			ok = 0;
+		}
+		if(close(t->notifyfd) < 0){
+			fail("close endpoint watches: %s", strerror(errno));
+			ok = 0;
+		}
+		t->notifyfd = -1;
+	}
+	if(t->socket[0] != '\0' && unlink(t->socket) < 0 && errno != ENOENT){
+		fail("remove IPC socket %s: %s", t->socket, strerror(errno));
+		ok = 0;
+	}
+	if(t->bus[0] != '\0' && !clearbus(t)) ok = 0;
+	if(!rmdirknown(t->bus)) ok = 0;
+	if(!rmdirknown(t->ibus)) ok = 0;
+	if(!rmdirknown(t->config)) ok = 0;
+	if(!rmdirknown(t->runtime)) ok = 0;
+	if(!rmdirknown(t->home)) ok = 0;
+	if(!rmdirknown(t->root)) ok = 0;
+	return ok;
+}
+
+int
+main(int argc, char **argv)
+{
+	Test test;
+	int ok;
+
+	if(argc != 3){
+		fprintf(stderr, "usage: daemon_collision_test strans mapdir\n");
+		return 2;
+	}
+	ok = setup(&test);
+	if(ok)
+		ok = runcollision(&test, argv[1], argv[2]);
+	if(!cleanup(&test))
+		ok = 0;
+	if(!ok){
+		showerrors(&test);
+		return 1;
+	}
+	printf("daemon endpoint collision ownership: ok\n");
+	return 0;
+}