Fix for emacs24

Author: bmastenbrook

rust-mode.el

@@ -1058,13 +1058,18 @@ the desired identifiers), but does not match type annotations \"foo::<\"."
   (let ((result
          ;; Replace /* with same number of spaces
          (replace-regexp-in-string
-          "\\(?:/\\*+\\)[!*]?"
+          "\\(?:/\\*+?\\)[!*]?"
           (lambda (s)
-            ;; We want the * to line up with the first * of the comment start
-            (concat (make-string (- (length s)
-                                    (if (or (string-suffix-p "!" s)
-                                            (string-suffix-p "**" s)) 2 1))
-                                 ?\x20) "*"))
+            ;; We want the * to line up with the first * of the
+            ;; comment start
+            (let ((offset (if (eq t
+                                  (compare-strings "/*" nil nil
+                                                   s
+                                                   (- (length s) 2)
+                                                   (length s)))
+                              1 2)))
+              (concat (make-string (- (length s) offset)
+                                   ?\x20) "*")))
           line-start)))
     ;; Make sure we've got at least one space at the end
     (if (not (= (aref result (- (length result) 1)) ?\x20))