bug#21205: Error during redisplay: (jit-lock-function 3491)

[张海君 <netjune@icloud.com>]

Yes, it is fixed. Thanks for your great work!

> 在 2015年8月8日，04:52，Alan Mackenzie <acm@muc.de> 写道：
> 
> Hello, Eli and Netjune.
> 
> On Fri, Aug 07, 2015 at 03:54:10PM +0300, Eli Zaretskii wrote:
>>> From: 张海君 <netjune@icloud.com>
>>> Date: Fri, 07 Aug 2015 18:43:54 +0800
> 
>>> Run emacs with "emacs -Q", and then eval the following code:
>>> ------------------------------------------------------------
>>> (setq font-lock-maximum-decoration 2
>>>      jit-lock-defer-time 0.05)
>>> (setq-default show-trailing-whitespace t)
>>> ------------------------------------------------------------
> 
>>> Then open the attached c file, and scroll down the buffer with key C-v C-v ... until the end of buffer.
>>> Switch to the message buffer *Message*. There are some error message as the following:
>>> ------------------------------------------------------------------------------
>>> Error during redisplay: (jit-lock-function 3102) signaled (error "Invalid search bound (wrong side of point)")
> 
>> The errors are triggered by c-syntactic-re-search-forward.  Here's the
>> backtrace from the first such error, with the current master:
> 
> [ .... ]
> 
>>  Lisp Backtrace:
>>  "re-search-forward" (0x825430)
>>  "c-syntactic-re-search-forward" (0x8259f0)
>>  "c-font-lock-declarators" (0x825fd0)
>>  0x1c9cda0 PVEC_COMPILED
>>  "font-lock-fontify-keywords-region" (0x826b30)
>>  "font-lock-default-fontify-region" (0x8270d0)
>>  "c-font-lock-fontify-region" (0x827680)
>>  "font-lock-fontify-region" (0x827c28)
> 
> [ .... ]
> 
> Thanks for that, Eli!  It made it fairly easy to track down the bug,
> which was simply failing to check if point had advanced too far at one
> critical place in c-font-lock-declarators.
> 
> Netjune: would you please try out the following patch (it should apply
> cleanly to the cc-fonts.el in ..../emacs-24.5/lisp/progmodes/), and
> confirm that the bug has been fixed, or tell me what is still causing
> problems.
> 
> 
> 
> diff -r 88b4140d56af cc-fonts.el
> --- a/cc-fonts.el    Tue May 12 10:03:55 2015 +0000
> +++ b/cc-fonts.el    Fri Aug 07 20:41:38 2015 +0000
> @@ -1141,6 +1141,7 @@
>                 (looking-at "{"))
>            (c-safe (c-forward-sexp) t) ; over { .... }
>              t)
> +            (< (point) limit)
>            ;; FIXME: Should look for c-decl-end markers here;
>            ;; we might go far into the following declarations
>            ;; in e.g. ObjC mode (see e.g. methods-4.m).
> 
> 
> Thanks for the bug report!
> 
> -- 
> Alan Mackenzie (Nuremberg, Germany).