[2.55.0] fixup! gvfs: add global command pre and post hook procs (#956)

Users were noticing some cases of infinite loops with the error message:

```
fatal: recursion detected in die handler
```

It's only happening for repos with a post-command hook, but it's not
deterministic. I'm not sure what is triggering the problem, but the
post-command hook is definitely able to recurse with its existing logic
around the `run_post_hook` variable.

Move this earlier to avoid a potential double-call. It's a fixup to the
introduction of the method, which may cause conflicts with later
adjustments to this method still in the branch thicket (but maybe those
should be squashed, too).

See #955 for the version on 2.54.0.

Author: dscho

git.c

@@ -528,9 +528,12 @@ static int run_post_command_hook(struct repository *r)
 
 	/*
 	 * Only run post_command if pre_command succeeded in this process
+	 * and we haven't attempted post_command yet.
 	 */
 	if (!run_post_hook)
 		return 0;
+	run_post_hook = 0;
+
 	lock = getenv("COMMAND_HOOK_LOCK");
 	if (!lock || strcmp(lock, "true"))
 		return 0;
@@ -539,8 +542,6 @@ static int run_post_command_hook(struct repository *r)
 	strvec_pushf(&opt.args, "--exit_code=%u", exit_code);
 	ret = run_hooks_opt(r, "post-command", &opt);
 
-	run_post_hook = 0;
-
 	errno = saved_errno;
 	strvec_clear(&sargv);
 	strvec_clear(&opt.args);

trace2/tr2_tbuf.c

@@ -3,45 +3,64 @@
 
 void tr2_tbuf_local_time(struct tr2_tbuf *tb)
 {
-	struct timeval tv;
-	struct tm tm;
+	struct timeval tv = { 0 };
+	struct tm tm = { 0 };
 	time_t secs;
+	int len;
 
 	gettimeofday(&tv, NULL);
 	secs = tv.tv_sec;
 	localtime_r(&secs, &tm);
 
-	xsnprintf(tb->buf, sizeof(tb->buf), "%02d:%02d:%02d.%06ld", tm.tm_hour,
-		  tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
+	len = snprintf(tb->buf, sizeof(tb->buf), "%02d:%02d:%02d.%06ld",
+		       tm.tm_hour, tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
+
+	if (len < 0 || (size_t)len >= sizeof(tb->buf)) {
+		const char *blank = "00:00:00.000000";
+		strlcpy(tb->buf, blank, sizeof(tb->buf));
+	}
 }
 
 void tr2_tbuf_utc_datetime_extended(struct tr2_tbuf *tb)
 {
-	struct timeval tv;
-	struct tm tm;
+	struct timeval tv = { 0 };
+	struct tm tm = { 0 };
 	time_t secs;
+	int len;
 
 	gettimeofday(&tv, NULL);
 	secs = tv.tv_sec;
 	gmtime_r(&secs, &tm);
 
-	xsnprintf(tb->buf, sizeof(tb->buf),
-		  "%4d-%02d-%02dT%02d:%02d:%02d.%06ldZ", tm.tm_year + 1900,
-		  tm.tm_mon + 1, tm.tm_mday, tm.tm_hour, tm.tm_min, tm.tm_sec,
-		  (long)tv.tv_usec);
+	len = snprintf(tb->buf, sizeof(tb->buf),
+		       "%4d-%02d-%02dT%02d:%02d:%02d.%06ldZ",
+		       tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+		       tm.tm_hour, tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
+
+	if (len < 0 || (size_t)len >= sizeof(tb->buf)) {
+		const char *blank = "1900-00-00T00:00:00.000000Z";
+		strlcpy(tb->buf, blank, sizeof(tb->buf));
+	}
 }
 
 void tr2_tbuf_utc_datetime(struct tr2_tbuf *tb)
 {
-	struct timeval tv;
-	struct tm tm;
+	struct timeval tv = { 0 };
+	struct tm tm = { 0 };
 	time_t secs;
+	int len;
 
 	gettimeofday(&tv, NULL);
 	secs = tv.tv_sec;
 	gmtime_r(&secs, &tm);
 
-	xsnprintf(tb->buf, sizeof(tb->buf), "%4d%02d%02dT%02d%02d%02d.%06ldZ",
-		  tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday, tm.tm_hour,
-		  tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
+	len = snprintf(tb->buf, sizeof(tb->buf),
+		       "%4d%02d%02dT%02d%02d%02d.%06ldZ",
+		       tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
+		       tm.tm_hour, tm.tm_min, tm.tm_sec, (long)tv.tv_usec);
+
+	if (len < 0 || (size_t)len >= sizeof(tb->buf)) {
+		const char *blank = "19000000T000000.000000Z";
+		strlcpy(tb->buf, blank, sizeof(tb->buf));
+	}
 }