mailinfo: do not concatenate charset= attribute values from mime headers

"Content-type: text/plain; charset=UTF-8" header should not appear
twice in the input, but it is always better to gracefully deal with
such a case.  The current code concatenates the value to the values
we have seen previously, producing nonsense such as "utf8UTF-8".

Instead of concatenating, forget the previous value and use the last
value we see.

Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 2 insertions, 3 deletions

diff --git a/builtin/mailinfo.c b/builtin/mailinfo.c
index eaf9e157a3..dd8b67cfaa 100644
--- a/builtin/mailinfo.c
+++ b/builtin/mailinfo.c
@@ -160,10 +160,9 @@ static int slurp_attr(const char *line, const char *name, struct strbuf *attr)
 	const char *ends, *ap = strcasestr(line, name);
 	size_t sz;
 
-	if (!ap) {
-		strbuf_setlen(attr, 0);
+	strbuf_setlen(attr, 0);
+	if (!ap)
 		return 0;
-	}
 	ap += strlen(name);
 	if (*ap == '"') {
 		ap++;