Subject: bug#33129: closed (Re: bug#33129: Acknowledgement (26.1; `vc-hg-find-file-hook' can never detect files with conflicts))

From: [email-masked] (GNU bug Tracking System)
Date: Sat, 03 Nov 2018 08:39:02 +0000

Your bug report

#33129: 26.1; `vc-hg-find-file-hook' can never detect files with conflicts

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 [email-masked].

-- 
33129: http://debbugs.gnu.org/cgi/bugreport.cgi?bug=33129
GNU Bug Tracking System
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Subject: Re: bug#33129: Acknowledgement (26.1; `vc-hg-find-file-hook' can never detect files with conflicts)
From: Eli Zaretskii <[email-masked]>
To: Daniel Pittman <[email-masked]>
Cc: [email-masked]
Date: Sat, 03 Nov 2018 10:37:52 +0200
List-Id: <debbugs-submit.debbugs.gnu.org>

> From: Daniel Pittman <[email-masked]>
> Date: Tue, 23 Oct 2018 12:10:35 -0400
> 
> Please find attached a patch fixing both the issues identified in this bug:

Thanks, pushed to the master branch.

Subject: 26.1; `vc-hg-find-file-hook' can never detect files with conflicts
From: Daniel Pittman <[email-masked]>
To: [email-masked]
Date: Tue, 23 Oct 2018 12:03:36 -0400
List-Id: <debbugs-submit.debbugs.gnu.org>

The `vc-hg-find-file-hook' tries to automatically invoke `smerge-mode'
when a file with conflicts is visited.  Unfortunately, due to incorrect
assumptions, it rarely -- possibly never -- actually manages to detect
the files.

There are two incorrect assumptions in the code that prevent this:

First, that `vc-state' will already be cached by the backend, which is
not true in at least the cases of visiting the file, reverting the file,
or using `vc-refresh-state'.

It is certainly possible that in some case or other the hook works, this
assumption means that it is almost never going to behave as intended.

Second, it assumes that a ".orig" backup file is created by Mercurial
next to the current file, which is only true by default: these files can
be redirected to an alternate path, or disabled entirely, by the user.

This is especially common when working on a network file-system, since
additional file operations can slow down the Mercurial merge process, or
when users have some other mechanism to handle the failure case.