Merge branch 'rr/forbid-bs-in-ref'

* rr/forbid-bs-in-ref:
  Disallow '\' in ref names

refs.c

@@ -682,12 +682,13 @@ int for_each_rawref(each_ref_fn fn, void *cb_data)
  * - it has ASCII control character, "~", "^", ":" or SP, anywhere, or
  * - it ends with a "/".
  * - it ends with ".lock"
+ * - it contains a "\" (backslash)
  */
 
 static inline int bad_ref_char(int ch)
 {
 	if (((unsigned) ch) <= ' ' ||
-	    ch == '~' || ch == '^' || ch == ':')
+	    ch == '~' || ch == '^' || ch == ':' || ch == '\\')
 		return 1;
 	/* 2.13 Pattern Matching Notation */
 	if (ch == '?' || ch == '[') /* Unsupported */