[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

Thanks for the submission. Minor comments below to give you a taste of
what it's like to contribute to this project...

On Sat, Mar 1, 2014 at 5:42 PM, kgeorgiou [off-list ref] wrote:

Subject: git-compat-util.h:rewrite skip_prefix() as loop

Space after colon. You might be able to provide more information in
the short summary of the subject. Perhaps something like this:

    Subject: skip_prefix(): avoid scanning 'prefix' twice

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.

Good description. In this project, use imperative tone:

    Rewrite skip_prefix() as loop...

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

That's okay. The purpose of the miniprojects is for you to get a taste
of what it's like to contribute to this project and to understand what
will be expected of you as a GSoC student; and to give the GSoC
mentors a chance to judge your abilities and observe how you interact
with reviewers.

Looking forward to any kind of feedback.

- Kyriakos Georgiou

There are two types of information you want to convey to readers. (1)
Patch description, explanation, justification before the "---" line
which is recorded in the permanent project history. (2) Commentary
below the "---" line for readers of the patch but not of interest once
the patch is accepted officially. The "as a miniproject for GSoC" and
all lines following it are just commentary which should go below the
"---" line.

Signed-off-by: kgeorgiou <redacted>

This project prefers real names, so:

    Signed-off-by: Kyriakos Georgiou <...>

Style nit: space after 'while'.

+               str++;
+               prefix++;
+       }
+       return *prefix ? NULL : str;
 }

 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)
--
1.8.3.2