[PATCH] get_sha1: handle special case $commit^{/}

["Nguyễn Thái Ngọc Duy" <pclouds@gmail.com>]

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>
---
 On top of nd/oneline-sha1-name-from-specific-ref

 sha1_name.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/sha1_name.c b/sha1_name.c
index 1ba4bc3..c5c59ce 100644
--- 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);
-- 
1.7.3.3.476.g10a82