Subject: bug#16585: closed (Re: [Emacs-diffs] trunk r116378: Fix c-invalidate-state-cache on narrowed buffers.)

From: [email-masked] (GNU bug Tracking System)
Date: Sun, 16 Feb 2014 02:56:03 +0000

Your bug report

#16585: c-invalidate-state-cache fails if called when narrowed

which was filed against the emacs,cc-mode package, has been closed.

The explanation is attached below, along with your original report.
If you require more details, please reply to [email-masked].

-- 
16585: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=16585
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Subject: Re: [Emacs-diffs] trunk r116378: Fix c-invalidate-state-cache on narrowed buffers.
From: Daniel Colascione <[email-masked]>
To: Alan Mackenzie <[email-masked]>, [email-masked], [email-masked]
Date: Sat, 15 Feb 2014 18:55:00 -0800
List-Id: <debbugs-submit.debbugs.gnu.org>

Thanks. Seems fixed now.

On 02/09/2014 04:38 AM, Alan Mackenzie wrote:
> ------------------------------------------------------------
> revno: 116378
> revision-id: [email-masked]
> parent: [email-masked]
> committer: Alan Mackenzie <[email-masked]>
> branch nick: trunk
> timestamp: Sun 2014-02-09 12:34:25 +0000
> message:
>    Fix c-invalidate-state-cache on narrowed buffers.
>    progmodes/cc-defs.el (c-with-all-but-one-cpps-commented-out): Widen when
>    setting and clearing the CPP delimiter properties.
> modified:
>    lisp/ChangeLog                 changelog-20091113204419-o5vbwnq5f7feedwu-1432
>    lisp/progmodes/cc-defs.el      ccdefs.el-20091113204419-o5vbwnq5f7feedwu-1226
>
>
>
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Subject: c-invalidate-state-cache fails if called when narrowed
From: Daniel Colascione <[email-masked]>
To: bug-emacs <[email-masked]>
Cc: Alan Mackenzie <[email-masked]>
Date: Tue, 28 Jan 2014 18:09:04 -0800
List-Id: <debbugs-submit.debbugs.gnu.org>

c-invalidate-state-cache can fail if called in a narrowed region: we end 
up calling c-clear-char-property for bob even if that's before 
point-min, causing remote-text-properties to raise (args-out-of-range 1 2).

We get into this situation when expanding yasnippet snippets; we're 
calling c-invalidate-state-cache from c-before-change.

To repro manually, first write this to some buffer.

#include <stdio.h>

void foo() {

}

Then (this is important) run M-x c-mode. After starting the mode, move 
point to inside foo's body and eval (save-restriction (narrow-to-region 
(point-at-bol) (point-at-eol)) (c-invalidate-state-cache (point))). You 
should break into the debugger.

The patch below seems correct and fixes the problem for me, but it'd be 
nice if Alan could take a look at it before I push it to trunk. The 
version of c-invalidate-state-cache in cc-mode trunk is very different.

=== modified file 'lisp/progmodes/cc-engine.el'
--- lisp/progmodes/cc-engine.el	2014-01-19 12:32:47 +0000
+++ lisp/progmodes/cc-engine.el	2014-01-29 02:07:44 +0000
@@ -3318,15 +3318,17 @@
    ;; of all parens in preprocessor constructs, except for any such 
construct
    ;; containing point.  We can then call `c-invalidate-state-cache-1' 
without
    ;; worrying further about macros and template delimiters.
-  (c-with-<->-as-parens-suppressed
-   (if (and c-state-old-cpp-beg
-	    (< c-state-old-cpp-beg here))
-       (c-with-all-but-one-cpps-commented-out
-	c-state-old-cpp-beg
-	(min c-state-old-cpp-end here)
-	(c-invalidate-state-cache-1 here))
-     (c-with-cpps-commented-out
-      (c-invalidate-state-cache-1 here)))))
+  (save-restriction
+    (widen)
+    (c-with-<->-as-parens-suppressed
+     (if (and c-state-old-cpp-beg
+              (< c-state-old-cpp-beg here))
+         (c-with-all-but-one-cpps-commented-out
+          c-state-old-cpp-beg
+          (min c-state-old-cpp-end here)
+          (c-invalidate-state-cache-1 here))
+       (c-with-cpps-commented-out
+        (c-invalidate-state-cache-1 here))))))

  (defmacro c-state-maybe-marker (place marker)
    ;; If PLACE is non-nil, return a marker marking it, otherwise nil.