bug#12029: 24.1; cc-imenu-objc-function generates invalid imenu alist

[Leo]

1. Open the attached file t.m
2. Move point to be on @interface
3. M-x imenu

,----[ Backtrace ]
| Debugger entered--Lisp error: (wrong-type-argument stringp nil)
|   string-match("\\`@interface\\'" nil)
|   (if (string-match re (car x)) (throw (quote found) (car x)))
|   (while --cl-dolist-temp-- (setq x (car --cl-dolist-temp--)) (if 
(string-match re (car x)) (throw (quote found) (car x))) (setq 
--cl-dolist-temp-- (cdr --cl-dolist-temp--)))
|   (let ((--cl-dolist-temp-- completions) x) (while --cl-dolist-temp-- (setq x 
(car --cl-dolist-temp--)) (if (string-match re (car x)) (throw (quote found) 
(car x))) (setq --cl-dolist-temp-- (cdr --cl-dolist-temp--))))
|   (catch (quote --cl-block-nil--) (let ((--cl-dolist-temp-- completions) x) 
(while --cl-dolist-temp-- (setq x (car --cl-dolist-temp--)) (if (string-match 
re (car x)) (throw (quote found) (car x))) (setq --cl-dolist-temp-- (cdr 
--cl-dolist-temp--)))))
|   (cl-block-wrapper (catch (quote --cl-block-nil--) (let ((--cl-dolist-temp-- 
completions) x) (while --cl-dolist-temp-- (setq x (car --cl-dolist-temp--)) (if 
(string-match re (car x)) (throw (quote found) (car x))) (setq 
--cl-dolist-temp-- (cdr --cl-dolist-temp--))))))
|   (block nil (let ((--cl-dolist-temp-- completions) x) (while 
--cl-dolist-temp-- (setq x (car --cl-dolist-temp--)) (if (string-match re (car 
x)) (throw (quote found) (car x))) (setq --cl-dolist-temp-- (cdr 
--cl-dolist-temp--)))))
|   (dolist (x completions) (if (string-match re (car x)) (throw (quote found) 
(car x))))
|   (while --cl-dolist-temp-- (setq re (car --cl-dolist-temp--)) (dolist (x 
completions) (if (string-match re (car x)) (throw (quote found) (car x)))) 
(setq --cl-dolist-temp-- (cdr --cl-dolist-temp--)))
|   (let ((--cl-dolist-temp-- (list (concat "\\`" (regexp-quote guess) "\\'") 
(concat "\\`" (regexp-quote guess)) (concat (regexp-quote guess) "\\'") 
(regexp-quote guess))) re) (while --cl-dolist-temp-- (setq re (car 
--cl-dolist-temp--)) (dolist (x completions) (if (string-match re (car x)) 
(throw (quote found) (car x)))) (setq --cl-dolist-temp-- (cdr 
--cl-dolist-temp--))))
|   (catch (quote --cl-block-nil--) (let ((--cl-dolist-temp-- (list (concat 
"\\`" (regexp-quote guess) "\\'") (concat "\\`" (regexp-quote guess)) (concat 
(regexp-quote guess) "\\'") (regexp-quote guess))) re) (while 
--cl-dolist-temp-- (setq re (car --cl-dolist-temp--)) (dolist (x completions) 
(if (string-match re (car x)) (throw (quote found) (car x)))) (setq 
--cl-dolist-temp-- (cdr --cl-dolist-temp--)))))
|   (cl-block-wrapper (catch (quote --cl-block-nil--) (let ((--cl-dolist-temp-- 
(list (concat "\\`" (regexp-quote guess) "\\'") (concat "\\`" (regexp-quote 
guess)) (concat (regexp-quote guess) "\\'") (regexp-quote guess))) re) (while 
--cl-dolist-temp-- (setq re (car --cl-dolist-temp--)) (dolist (x completions) 
(if (string-match re (car x)) (throw (quote found) (car x)))) (setq 
--cl-dolist-temp-- (cdr --cl-dolist-temp--))))))
|   (block nil (let ((--cl-dolist-temp-- (list (concat "\\`" (regexp-quote 
guess) "\\'") (concat "\\`" (regexp-quote guess)) (concat (regexp-quote guess) 
"\\'") (regexp-quote guess))) re) (while --cl-dolist-temp-- (setq re (car 
--cl-dolist-temp--)) (dolist (x completions) (if (string-match re (car x)) 
(throw (quote found) (car x)))) (setq --cl-dolist-temp-- (cdr 
--cl-dolist-temp--)))))
|   (dolist (re (list (concat "\\`" (regexp-quote guess) "\\'") (concat "\\`" 
(regexp-quote guess)) (concat (regexp-quote guess) "\\'") (regexp-quote 
guess))) (dolist (x completions) (if (string-match re (car x)) (throw (quote 
found) (car x)))))
|   (if (assoc guess completions) guess (dolist (re (list (concat "\\`" 
(regexp-quote guess) "\\'") (concat "\\`" (regexp-quote guess)) (concat 
(regexp-quote guess) "\\'") (regexp-quote guess))) (dolist (x completions) (if 
(string-match re (car x)) (throw (quote found) (car x))))))
|   (let ((case-fold-search t)) (if (assoc guess completions) guess (dolist (re 
(list (concat "\\`" (regexp-quote guess) "\\'") (concat "\\`" (regexp-quote 
guess)) (concat (regexp-quote guess) "\\'") (regexp-quote guess))) (dolist (x 
completions) (if (string-match re (car x)) (throw (quote found) (car x)))))))
|   (catch (quote found) (let ((case-fold-search t)) (if (assoc guess 
completions) guess (dolist (re (list (concat "\\`" (regexp-quote guess) "\\'") 
(concat "\\`" (regexp-quote guess)) (concat (regexp-quote guess) "\\'") 
(regexp-quote guess))) (dolist (x completions) (if (string-match re (car x)) 
(throw (quote found) (car x))))))))
|   imenu-find-default(#("@interface" 0 10 (fontified t face 
font-lock-keyword-face)) (("*Rescan*" . -99) ("BarCodeViewController(Private)" 
("@interface" . 1) ("-initReaderView" . 45)) (nil) ("BarCodeViewController" 
("@implementation" . 76) ("-alertView:didDismissWithButtonIndex:" . 140))))
|   imenu--completion-buffer((("*Rescan*" . -99) 
("BarCodeViewController(Private)" ("@interface" . 1) ("-initReaderView" . 45)) 
nil ("BarCodeViewController" ("@implementation" . 76) 
("-alertView:didDismissWithButtonIndex:" . 140))) nil)
|   imenu-choose-buffer-index()
|   (list (imenu-choose-buffer-index))
|   call-interactively(imenu t nil)
|   execute-extended-command(nil)
|   call-interactively(execute-extended-command nil nil)
`----

This is due to cc-imenu-objc-function generates invalid imenu alist:

,----[ C-h v imenu--index-alist RET ]
| imenu--index-alist is a variable defined in `imenu.el'.
| Its value is nil
| 
|   Automatically becomes buffer-local when set in any fashion.
|   This variable is potentially risky when used as a file local variable.
| 
| Documentation:
| The buffer index alist computed for this buffer in Imenu.
| 
| Simple elements in the alist look like (INDEX-NAME . POSITION).
| POSITION is the buffer position of the item; to go to the item
| is simply to move point to that position.
| 
| Special elements look like (INDEX-NAME POSITION FUNCTION ARGUMENTS...).
| To "go to" a special element means applying FUNCTION
| to INDEX-NAME, POSITION, and the ARGUMENTS.
| 
| A nested sub-alist element looks like (INDEX-NAME SUB-ALIST).
| The function `imenu--subalist-p' tests an element and returns t
| if it is a sub-alist.
| 
| There is one simple element with negative POSITION; selecting that
| element recalculates the buffer's index alist.
| 
| [back]
`----

The following patch fixes this bug:

 lisp/progmodes/cc-menus.el |    8 ++------
 1 files changed, 2 insertions(+), 6 deletions(-)

        Modified lisp/progmodes/cc-menus.el
diff --git a/lisp/progmodes/cc-menus.el b/lisp/progmodes/cc-menus.el
index a53d65f6..76e3002a 100644
--- a/lisp/progmodes/cc-menus.el
+++ b/lisp/progmodes/cc-menus.el
@@ -399,14 +399,10 @@ (defun cc-imenu-objc-function ()
                str2 "@protocol")))
        (setq str (cc-imenu-objc-remove-white-space str))
        (setq methodlist (cons (cons str2
-                             (match-beginning langnum))
+                                    (match-beginning langnum))
                               methodlist))
-       (setq toplist (cons nil (cons (cons str
-                                         methodlist) toplist))
+       (setq toplist (cons (cons str methodlist) toplist)
              methodlist nil))))
-    ;;
-    (if (eq (car toplist) nil)
-       (setq toplist (cdr toplist)))
 
     ;; In this buffer, there is only one or zero 
@{interface|implementation|protocol}.
     (if (< classcount 2)

t.m
Description: t.m