GNU bug report logs - #23397
25.0.92; assertion failure auto-reverting a file being overwritten

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Package: emacs;

Reported by: Ken Raeburn <raeburn <at> permabit.com>

Date: Thu, 28 Apr 2016 22:07:01 UTC

Severity: normal

Tags: confirmed

Found in versions 26.1, 25.0.92

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From: Eli Zaretskii <eliz <at> gnu.org>
To: Noam Postavsky <npostavs <at> gmail.com>
Cc: raeburn <at> permabit.com, 23397 <at> debbugs.gnu.org
Subject: bug#23397: 25.0.92; assertion failure auto-reverting a file being overwritten
Date: Sun, 17 Jun 2018 08:36:35 +0300
> From: Noam Postavsky <npostavs <at> gmail.com>
> Cc: Eli Zaretskii <eliz <at> gnu.org>,  23397 <at> debbugs.gnu.org
> Date: Sat, 16 Jun 2018 17:45:36 -0400
> 
> I don't quite understand what the overlap expression is trying to
> compute though.

It prevents us from re-using the same portion of buffer text for
matching both at start and at end of the file.  This could happen,
e.g., with buffers whose contents is the same character, and a file
whose contents is mostly the same, but larger, and with a few
different characters in the middle.  Then the "same_at_end" loop could
inadvertently match a part of the buffer that was already matched by
the "same_at_start" loop.

The overlap expression computes the portion of the buffer that was
matched by both "same_at_start" and "same_at_end" loops.




This bug report was last modified 4 years and 340 days ago.

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