Merge branch 'jc/maint-simpler-common-prefix'

* jc/maint-simpler-common-prefix:
  common_prefix: simplify and fix scanning for prefixes

diff --git a/dir.c b/dir.c
index 5e36f8e616d63f8a9c5950897e0f06235d8e9acf..151ea670d961d39394990f122469557b6f217de3 100644 (file)
--- a/dir.c
+++ b/dir.c
@@ -31,22 +31,22 @@ static int common_prefix(const char **pathspec)
        if (!slash)
                return 0;
 
+       /*
+        * The first 'prefix' characters of 'path' are common leading
+        * path components among the pathspecs we have seen so far,
+        * including the trailing slash.
+        */
        prefix = slash - path + 1;
        while ((next = *++pathspec) != NULL) {
-               int len = strlen(next);
-               if (len >= prefix && !memcmp(path, next, prefix))
+               int len, last_matching_slash = -1;
+               for (len = 0; len < prefix && next[len] == path[len]; len++)
+                       if (next[len] == '/')
+                               last_matching_slash = len;
+               if (len == prefix)
                        continue;
-               len = prefix - 1;
-               for (;;) {
-                       if (!len)
-                               return 0;
-                       if (next[--len] != '/')
-                               continue;
-                       if (memcmp(path, next, len+1))
-                               continue;
-                       prefix = len + 1;
-                       break;
-               }
+               if (last_matching_slash < 0)
+                       return 0;
+               prefix = last_matching_slash + 1;
        }
        return prefix;
 }