GNU bug report logs - #71604
diff--get-revision-properties calls set-auto-mode twice

Previous Next

Full log

View this message in rfc822 format

From: help-debbugs <at> gnu.org (GNU bug Tracking System)
To: Dmitry Gutov <dmitry <at> gutov.dev>
Subject: bug#71604: closed (Re: bug#71604: diff--get-revision-properties
 calls set-auto-mode twice)
Date: Mon, 17 Jun 2024 20:02:02 +0000

[Message part 1 (text/plain, inline)]

Your bug report

#71604: diff--get-revision-properties calls set-auto-mode twice

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

The explanation is attached below, along with your original report.
If you require more details, please reply to 71604 <at> debbugs.gnu.org.

-- 
71604: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=71604
GNU Bug Tracking System
Contact help-debbugs <at> gnu.org with problems

[Message part 2 (message/rfc822, inline)]

From: Dmitry Gutov <dmitry <at> gutov.dev>
To: Juri Linkov <juri <at> linkov.net>
Cc: 71604-done <at> debbugs.gnu.org
Subject: Re: bug#71604: diff--get-revision-properties calls set-auto-mode twice
Date: Mon, 17 Jun 2024 23:01:34 +0300

On 17/06/2024 19:33, Juri Linkov wrote:
>> vc-find-revision-no-save calls set-auto-mode, and then we repeat that call
>> in diff-syntax-fontify-props.
>>
>> Which is a problem with CC Mode because it parses the buffer inside the
>> major mode function, and ends up doing that twice, at least the first time
>> the buffer is initialized before being saved to revision cache. Not exactly
>> double the work, but more work nevertheless.
>>
>> This is a split off from https://debbugs.gnu.org/61667#587. I thought
>> I recalled an existing report of vc-diff being slow, but apparently not.
>>
>> @@ -2883,9 +2883,6 @@ diff--get-revision-properties
>>            (buffer (cdr entry)))
>>       (if (buffer-live-p buffer)
>>           (progn
>> -          ;; Don't re-initialize the buffer (which would throw
>> -          ;; away the previous fontification work).
>> -          (setq file nil)
>>             (setq diff--cached-revision-buffers
>>                   (cons entry
>>                         (delq entry diff--cached-revision-buffers))))
>> @@ -2905,7 +2902,8 @@ diff--get-revision-properties
>>       (diff--cache-schedule-clean)
>>       (and buffer
>>            (with-current-buffer buffer
>> -           (diff-syntax-fontify-props file text line-nb)))))
>> +           ;; major mode is set in vc-find-revision-no-save already.
>> +           (diff-syntax-fontify-props nil text line-nb)))))
> 
> Thanks, looks correct.

Pushed to master, thanks.

[Message part 3 (message/rfc822, inline)]

From: Dmitry Gutov <dmitry <at> gutov.dev>
To: bug-gnu-emacs <at> gnu.org
Subject: diff--get-revision-properties calls set-auto-mode twice
Date: Mon, 17 Jun 2024 05:25:31 +0300

X-Debbugs-Cc: Juri Linkov <juri <at> linkov.net>
Tags: patch

vc-find-revision-no-save calls set-auto-mode, and then we repeat that 
call in diff-syntax-fontify-props.

Which is a problem with CC Mode because it parses the buffer inside the 
major mode function, and ends up doing that twice, at least the first 
time the buffer is initialized before being saved to revision cache. Not 
exactly double the work, but more work nevertheless.

This is a split off from https://debbugs.gnu.org/61667#587. I thought I 
recalled an existing report of vc-diff being slow, but apparently not.

diff --git a/lisp/vc/diff-mode.el b/lisp/vc/diff-mode.el
index c0269d882b9..cc5509ca347 100644
--- a/lisp/vc/diff-mode.el
+++ b/lisp/vc/diff-mode.el
@@ -2883,9 +2883,6 @@ diff--get-revision-properties
          (buffer (cdr entry)))
     (if (buffer-live-p buffer)
         (progn
-          ;; Don't re-initialize the buffer (which would throw
-          ;; away the previous fontification work).
-          (setq file nil)
           (setq diff--cached-revision-buffers
                 (cons entry
                       (delq entry diff--cached-revision-buffers))))
@@ -2905,7 +2902,8 @@ diff--get-revision-properties
     (diff--cache-schedule-clean)
     (and buffer
          (with-current-buffer buffer
-           (diff-syntax-fontify-props file text line-nb)))))
+           ;; major mode is set in vc-find-revision-no-save already.
+           (diff-syntax-fontify-props nil text line-nb)))))

 (defun diff-syntax-fontify-hunk (beg end old)
   "Highlight source language syntax in diff hunk between BEG and END.

Previous Next

GNU bug tracking system
Copyright (C) 1999 Darren O. Benham, 1997,2003 nCipher Corporation Ltd, 1994-97 Ian Jackson.