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authorVincent Ambo <mail@tazj.in>2020-11-21T18·20+0100
committerVincent Ambo <mail@tazj.in>2020-11-21T18·45+0100
commitf4609b896fac842433bd495c166d5987852a6a73 (patch)
tree95511c465c54c4f5d27e5d39ce187e2a1dd82bd3 /third_party/git/usage.c
parent082c006c04343a78d87b6c6ab3608c25d6213c3f (diff)
merge(3p/git): Merge git subtree at v2.29.2 r/1890
This also bumps the stable nixpkgs to 20.09 as of 2020-11-21, because
there is some breakage in the git build related to the netrc
credentials helper which someone has taken care of in nixpkgs.

The stable channel is not used for anything other than git, so this
should be fine.

Change-Id: I3575a19dab09e1e9556cf8231d717de9890484fb
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)