about summary refs log tree commit diff
path: root/third_party/git/usage.c
diff options
context:
space:
mode:
authorVincent Ambo <tazjin@google.com>2020-05-22T16·46+0100
committerVincent Ambo <tazjin@google.com>2020-05-22T16·46+0100
commit5229c9b232de5bfa959ad6ebbb4c8192ac513352 (patch)
tree8539e7e23682cac110900f946f034ae44162cacd /third_party/git/usage.c
parentf2b211131f2347342dde63975b09cf603149f1a3 (diff)
parent8518a7a51faaf50f830646d4c3585f51236b9349 (diff)
merge(3p/git): Merge git upstream at v2.26.2 r/808
Diffstat (limited to 'third_party/git/usage.c')
-rw-r--r--third_party/git/usage.c20
1 files changed, 16 insertions, 4 deletions
diff --git a/third_party/git/usage.c b/third_party/git/usage.c
index 2fdb20086bd6..58fb5fff5f24 100644
--- a/third_party/git/usage.c
+++ b/third_party/git/usage.c
@@ -9,14 +9,26 @@
 void vreportf(const char *prefix, const char *err, va_list params)
 {
 	char msg[4096];
-	char *p;
+	char *p, *pend = msg + sizeof(msg);
+	size_t prefix_len = strlen(prefix);
 
-	vsnprintf(msg, sizeof(msg), err, params);
-	for (p = msg; *p; p++) {
+	if (sizeof(msg) <= prefix_len) {
+		fprintf(stderr, "BUG!!! too long a prefix '%s'\n", prefix);
+		abort();
+	}
+	memcpy(msg, prefix, prefix_len);
+	p = msg + prefix_len;
+	if (vsnprintf(p, pend - p, err, params) < 0)
+		*p = '\0'; /* vsnprintf() failed, clip at prefix */
+
+	for (; p != pend - 1 && *p; p++) {
 		if (iscntrl(*p) && *p != '\t' && *p != '\n')
 			*p = '?';
 	}
-	fprintf(stderr, "%s%s\n", prefix, msg);
+
+	*(p++) = '\n'; /* we no longer need a NUL */
+	fflush(stderr);
+	write_in_full(2, msg, p - msg);
 }
 
 static NORETURN void usage_builtin(const char *err, va_list params)