Refactor check_refname_format()

Among other things, extract a function check_refname_component().

Signed-off-by: Michael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

diff --git a/refs.c b/refs.c
index aaa87304a4c3162805f692ae7ba5bdef57ef8db1..52597244b871887028aafbefece4d22bbe1001ec 100644 (file)
--- a/refs.c
+++ b/refs.c
@@ -872,55 +872,70 @@ static inline int bad_ref_char(int ch)
        return 0;
 }
 
+/*
+ * Try to read one refname component from the front of ref.  Return
+ * the length of the component found, or -1 if the component is not
+ * legal.
+ */
+static int check_refname_component(const char *ref)
+{
+       const char *cp;
+       char last = '\0';
+
+       for (cp = ref; ; cp++) {
+               char ch = *cp;
+               if (ch == '\0' || ch == '/')
+                       break;
+               if (bad_ref_char(ch))
+                       return -1; /* Illegal character in refname. */
+               if (last == '.' && ch == '.')
+                       return -1; /* Refname contains "..". */
+               if (last == '@' && ch == '{')
+                       return -1; /* Refname contains "@{". */
+               last = ch;
+       }
+       if (cp == ref)
+               return -1; /* Component has zero length. */
+       if (ref[0] == '.')
+               return -1; /* Component starts with '.'. */
+       return cp - ref;
+}
+
 int check_refname_format(const char *ref, int flags)
 {
-       int ch, level, last;
-       const char *cp = ref;
+       int component_len, component_count = 0;
 
-       level = 0;
        while (1) {
-               while ((ch = *cp++) == '/')
-                       ; /* tolerate duplicated slashes */
-               if (!ch)
-                       /* should not end with slashes */
-                       return -1;
-
-               /* we are at the beginning of the path component */
-               if (ch == '.')
-                       return -1;
-               if (bad_ref_char(ch)) {
-                       if ((flags & REFNAME_REFSPEC_PATTERN) && ch == '*' &&
-                               (!*cp || *cp == '/'))
+               while (*ref == '/')
+                       ref++; /* tolerate leading and repeated slashes */
+
+               /* We are at the start of a path component. */
+               component_len = check_refname_component(ref);
+               if (component_len < 0) {
+                       if ((flags & REFNAME_REFSPEC_PATTERN) &&
+                                       ref[0] == '*' &&
+                                       (ref[1] == '\0' || ref[1] == '/')) {
                                /* Accept one wildcard as a full refname component. */
                                flags &= ~REFNAME_REFSPEC_PATTERN;
-                       else
-                               return -1;
-               }
-
-               last = ch;
-               /* scan the rest of the path component */
-               while ((ch = *cp++) != 0) {
-                       if (bad_ref_char(ch))
-                               return -1;
-                       if (ch == '/')
-                               break;
-                       if (last == '.' && ch == '.')
-                               return -1;
-                       if (last == '@' && ch == '{')
-                               return -1;
-                       last = ch;
-               }
-               level++;
-               if (!ch) {
-                       if (ref <= cp - 2 && cp[-2] == '.')
-                               return -1;
-                       if (level < 2 && !(flags & REFNAME_ALLOW_ONELEVEL))
-                               return -1;
-                       if (has_extension(ref, ".lock"))
+                               component_len = 1;
+                       } else {
                                return -1;
-                       return 0;
+                       }
                }
+               component_count++;
+               if (ref[component_len] == '\0')
+                       break;
+               /* Skip to next component. */
+               ref += component_len + 1;
        }
+
+       if (ref[component_len - 1] == '.')
+               return -1; /* Refname ends with '.'. */
+       if (component_len >= 5 && !memcmp(&ref[component_len - 5], ".lock", 5))
+               return -1; /* Refname ends with ".lock". */
+       if (!(flags & REFNAME_ALLOW_ONELEVEL) && component_count < 2)
+               return -1; /* Refname has only one component. */
+       return 0;
 }
 
 const char *prettify_refname(const char *name)