git-format-patch: do not crash with format.headers without value.
An incorrect config file can say:
[format]
headers
and crash the parsing.
Signed-off-by: Junio C Hamano <junkio@cox.net>
diff --git a/builtin-log.c b/builtin-log.c
index 7397a5a..1cd9d3f 100644
--- a/builtin-log.c
+++ b/builtin-log.c
@@ -202,7 +202,11 @@
static int git_format_config(const char *var, const char *value)
{
if (!strcmp(var, "format.headers")) {
- int len = strlen(value);
+ int len;
+
+ if (!value)
+ die("format.headers without value");
+ len = strlen(value);
extra_headers_size += len + 1;
extra_headers = xrealloc(extra_headers, extra_headers_size);
extra_headers[extra_headers_size - len - 1] = 0;
