stat_opt: check extra strlen call

diff --git a/git-compat-util.h b/git-compat-util.h
index b6f03b36dc762b891e77a5ca44e7ca5f270c5af9..d29e1dff08de9caa2b37eff71bffe7d37225796e 100644 (file)
--- a/git-compat-util.h
+++ b/git-compat-util.h
@@ -349,13 +349,32 @@ extern void set_die_is_recursing_routine(int (*routine)(void));
 extern int starts_with(const char *str, const char *prefix);
 extern int ends_with(const char *str, const char *suffix);
 
-static inline const char *skip_prefix(const char *str, const char *prefix)
+/*
+ * If the string "str" begins with the string found in "prefix", return 1.
+ * The "out" parameter is set to "str + strlen(prefix)" (i.e., to the point in
+ * the string right after the prefix).
+ *
+ * Otherwise, return 0 and leave "out" untouched.
+ *
+ * Examples:
+ *
+ *   [extract branch name, fail if not a branch]
+ *   if (!skip_prefix(ref, "refs/heads/", &branch)
+ *     return -1;
+ *
+ *   [skip prefix if present, otherwise use whole string]
+ *   skip_prefix(name, "refs/heads/", &name);
+ */
+static inline int skip_prefix(const char *str, const char *prefix,
+                             const char **out)
 {
        do {
-               if (!*prefix)
-                       return str;
+               if (!*prefix) {
+                       *out = str;
+                       return 1;
+               }
        } while (*str++ == *prefix++);
-       return NULL;
+       return 0;
 }
 
 #if defined(NO_MMAP) || defined(USE_WIN32_MMAP)