From: Brandon Williams <bmwill@google.com>
To: Johannes Schindelin <johannes.schindelin@gmx.de>
Cc: git@vger.kernel.org, Junio C Hamano <gitster@pobox.com>
Subject: Re: [PATCH 0/9] Avoid problem where git_dir is set after alias expansion
Date: Wed, 7 Jun 2017 11:30:08 -0700 [thread overview]
Message-ID: <20170607183008.GG110638@google.com> (raw)
In-Reply-To: <cover.1496851544.git.johannes.schindelin@gmx.de>
On 06/07, Johannes Schindelin wrote:
> When expanding an alias in a subdirectory, we setup the git_dir
> (gently), read the config, and then restore the "env" (e.g. the current
> working directory) so that the command specified by the alias can run
> correctly.
>
> What we failed to reset was the git_dir, meaning that in the most common
> case, it was now pointing to a .git/ directory *in the subdirectory*.
>
> This problem was identified in the GVFS fork, where a pre-command hook
> was introduced to allow pre-fetching missing blobs.
>
> An early quick fix in the GVFS fork simply built on top of the
> save_env_before_alias() hack, introducing another hack that saves the
> git_dir and restores it after an alias is expanded:
>
> https://github.com/Microsoft/git/commit/2d859ba3b
>
> That is very hacky, though, and it is much better (although much more
> involved, too) to fix this "properly", i.e. by replacing the ugly
> save/restore logic by simply using the early config code path.
>
> However, aliases are strange beasts.
>
> When an alias refers to a single Git command (originally the sole
> intention of aliases), the current working directory is restored to what
> it had been before expanding the alias.
>
> But when an alias starts with an exclamation point, i.e. referring to a
> command-line to be interpreted by the shell, the current working
> directory is no longer in the subdirectory but instead in the worktree's
> top-level directory.
>
> This is even true for worktrees added by `git worktree add`.
>
> But when we are inside the .git/ directory, the current working
> directory is *restored* to the subdirectory inside the .git/ directory.
>
> In short, the logic is a bit complicated what is the expected current
> working directory after expanding an alias and before actually running
> it.
>
> That is why this patch series had to expand the signature of the early
> config machinery to return the additional information for aliases'
> benefit.
>
Looks good, I don't have any major issues with the series, just some
comments for clarity mostly. And relevant to this series, you may be
interested in looking at patch 03/31 in my repository object series as
that may have an impact on the early config stuff.
>
> Johannes Schindelin (9):
> discover_git_directory(): avoid setting invalid git_dir
> config: report correct line number upon error
> help: use early config when autocorrecting aliases
> read_early_config(): optionally return the worktree's top-level
> directory
> t1308: relax the test verifying that empty alias values are disallowed
> t7006: demonstrate a problem with aliases in subdirectories
> alias_lookup(): optionally return top-level directory
> Use the early config machinery to expand aliases
> TODO:
>
> alias.c | 33 +++++++++++++++++++++-------
> builtin/help.c | 2 +-
> cache.h | 7 +++---
> config.c | 7 +++---
> git.c | 59 ++++++--------------------------------------------
> help.c | 2 +-
> pager.c | 4 ++--
> setup.c | 13 +++++++++--
> t/helper/test-config.c | 2 +-
> t/t1308-config-set.sh | 4 +++-
> t/t7006-pager.sh | 11 ++++++++++
> 11 files changed, 70 insertions(+), 74 deletions(-)
>
>
> base-commit: 8d1b10321b20bd2a73a5b561cfc3cf2e8051b70b
> Published-As: https://github.com/dscho/git/releases/tag/alias-early-config-v1
> Fetch-It-Via: git fetch https://github.com/dscho/git alias-early-config-v1
> --
> 2.13.0.windows.1.460.g13f583bedb5
>
--
Brandon Williams
next prev parent reply other threads:[~2017-06-07 18:30 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-06-07 16:06 [PATCH 0/9] Avoid problem where git_dir is set after alias expansion Johannes Schindelin
2017-06-07 16:06 ` [PATCH 1/9] discover_git_directory(): avoid setting invalid git_dir Johannes Schindelin
2017-06-07 17:45 ` Brandon Williams
2017-06-08 10:00 ` Johannes Schindelin
2017-06-07 16:06 ` [PATCH 2/9] config: report correct line number upon error Johannes Schindelin
2017-06-09 17:01 ` Junio C Hamano
2017-06-07 16:06 ` [PATCH 3/9] help: use early config when autocorrecting aliases Johannes Schindelin
2017-06-07 17:51 ` Brandon Williams
2017-06-08 10:02 ` Johannes Schindelin
2017-06-09 17:05 ` Junio C Hamano
2017-06-07 16:06 ` [PATCH 4/9] read_early_config(): optionally return the worktree's top-level directory Johannes Schindelin
2017-06-07 18:13 ` Brandon Williams
2017-06-08 10:20 ` Johannes Schindelin
2017-06-08 14:46 ` Brandon Williams
2017-06-08 15:30 ` Johannes Schindelin
2017-06-08 16:32 ` Brandon Williams
2017-06-08 18:52 ` Johannes Schindelin
2017-06-08 18:54 ` Brandon Williams
2017-06-07 16:06 ` [PATCH 5/9] t1308: relax the test verifying that empty alias values are disallowed Johannes Schindelin
2017-06-07 18:15 ` Brandon Williams
2017-06-08 10:22 ` Johannes Schindelin
2017-06-08 14:47 ` Brandon Williams
2017-06-10 1:28 ` Junio C Hamano
2017-06-07 16:06 ` [PATCH 6/9] t7006: demonstrate a problem with aliases in subdirectories Johannes Schindelin
2017-06-07 16:06 ` [PATCH 7/9] alias_lookup(): optionally return top-level directory Johannes Schindelin
2017-06-07 16:07 ` [PATCH 8/9] Use the early config machinery to expand aliases Johannes Schindelin
2017-06-07 18:26 ` Brandon Williams
2017-06-08 10:25 ` Johannes Schindelin
2017-06-08 14:51 ` Brandon Williams
2017-06-10 1:33 ` Junio C Hamano
2017-06-07 16:09 ` [PATCH 0/9] Avoid problem where git_dir is set after alias expansion Johannes Schindelin
2017-06-07 18:30 ` Brandon Williams [this message]
2017-06-08 10:27 ` Johannes Schindelin
2017-06-08 16:33 ` Brandon Williams
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