get_sha1: handle special case $commit^{/}

Empty regex pattern should always match. But the exact behavior of
regexec() may vary. Because it always matches anyway, we can just
return 'matched' without calling regex machinery.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/sha1_name.c b/sha1_name.c
index 1ba4bc3b686f30d77ab0aad881681b4d6b53531f..c5c59ced7f0cbd9ced026d44df6439da65082fb8 100644 (file)
--- a/sha1_name.c
+++ b/sha1_name.c
@@ -599,6 +599,13 @@ static int peel_onion(const char *name, int len, unsigned char *sha1)
                int ret;
                struct commit_list *list = NULL;
 
+               /*
+                * $commit^{/}. Some regex implementation may reject.
+                * We don't need regex anyway. '' pattern always matches.
+                */
+               if (sp[1] == '}')
+                       return 0;
+
                prefix = xstrndup(sp + 1, name + len - 1 - (sp + 1));
                commit_list_insert((struct commit *)o, &list);
                ret = get_sha1_oneline(prefix, sha1, list);