[PATCH][GSoC] git-compat-util.h:rewrite skip_prefix() as loop

Rewritten git-compat-util.h:skip_prefix() as a loop, so that it doesn't have to
scan through the prefix string twice as a miniproject for GSoC 2014.

(I've just noticed that this miniproject has already been tackled by another 
contributor, if that's a problem I can pick something else.)

Looking forward to any kind of feedback.

- Kyriakos Georgiou

Signed-off-by: kgeorgiou <redacted>
---
 git-compat-util.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/git-compat-util.h b/git-compat-util.h
index 614a5e9..713f37a 100644
--- a/git-compat-util.h
+++ b/git-compat-util.h

@@ -357,8 +357,11 @@ extern int suffixcmp(const char *str, const char *suffix);
 
 static inline const char *skip_prefix(const char *str, const char *prefix)
 {
-	size_t len = strlen(prefix);
-	return strncmp(str, prefix, len) ? NULL : str + len;
+	while(*prefix && *str == *prefix) {
+		str++;
+		prefix++;
+	}
+	return *prefix ? NULL : str;
 }
 
 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)

-- 
1.8.3.2