Re: [git-users] Problem using detached worktrees with commands implemented in scripts

From: Philip Oakley <philipoakley@iee.org>
Date: Oct 18, 2013, 20:40 UTC
Message-ID: <03C57561C4664D048C2F28134019C391@PhilipOakley>
In-Reply-To: <20131017224834.GW9464@google.com>

From: "Jonathan Nieder" <jrnieder@gmail.com>

> Philip Oakley wrote:

It was Dale that had the problem, I was just suggesting where he might want to look... ;-)

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>
>> A bit more looking gave that the cd_to_toplevel () in git-sh-setup.sh
>> directly uses `git rev-parse --show-toplevel`, which simply returns
>> work_tree (static char *work_tree; in environment.c, with comment /*
>> This is set by setup_git_dir_gently() and/or git_default_config()
>> */), apparently without a check for the GIT_WORK_TREE.
>
> Getting closer. :)
>
> The usual way to use GIT_WORK_TREE is along with GIT_DIR.

When re-checking the manual's git(1) env variable section the comment that implies this didn't read well "The value will not be used in combination...". The section probably needs that to be stated explicitly ("an exported GIT_WORK_TREE is ignored if GIT_DIR is not set").

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>   That takes
> you into the setup_explicit_git_dir() codepath, which does respect
> GIT_WORK_TREE as it should.  (setup_discovered_git_dir does, too.)
>
> The strange behavior you ran into is that unlike, say, git-pull.sh and
> git-am.sh, filter-branch does not set SUBDIRECTORY_OK, store the
> prefix from 'git rev-parse --show-prefix', and then cd_to_toplevel at
> the top of the script.  In other words, nobody bothered to make it
> work from anywhere other than the toplevel of the worktree to begin
> with, and nobody wanted it enough to fix it later.
>

I maybe wrong, but I thought that in Dale's case he was already at the same level as the GIT_WORK_TREE he had set, so may not have expected to need a cd_to_toplevel

Dale did propose a patch in http://thread.gmane.org/gmane.comp.version-control.git/236260 as the error was from later in the setup script.

> Hope that helps,
> Jonathan
>

Philip