Merge branch 'dk/skip-prefix-scan-only-once'

Update implementation of skip_prefix() to scan only once; given
that most "prefix" arguments to the inline function are constant
strings whose strlen() can be determined at the compile time, this
might actually make things worse with a compiler with sufficient
intelligence.

* dk/skip-prefix-scan-only-once:
  skip_prefix(): scan prefix only once

git-compat-util.h

@@ -343,8 +343,11 @@ extern int ends_with(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;
+	do {
+		if (!*prefix)
+			return str;
+	} while (*str++ == *prefix++);
+	return NULL;
 }
 
 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)