Re: bug with .git file and aliases

From: Geoffrey Irving <irving@naml.us>
Date: Aug 10, 2009, 20:22 UTC
Message-ID: <7f9d599f0908101322i46384247m303e28955f88bbb@mail.gmail.com>
In-Reply-To: <20090720152117.GB5347@coredump.intra.peff.net>

On Mon, Jul 20, 2009 at 11:21 AM, Jeff King<peff@peff.net> wrote:

Show 15 quoted lines

> On Mon, Jul 20, 2009 at 09:54:12AM -0400, Geoffrey Irving wrote:
>
>> git 1.6.3.3 has a bug related to .git file support and aliases.
>> Specifically, if you make an alias for status and call it from a
>> subdirectory, git status chdirs into the true .git dir but then
>> chdir's back to the wrong place in order to run the lstats for status.
>>  The result is that git status thinks all files have disappeared.
>
> Yeah, this is a known problem. The problem is that the 'git' wrapper
> sets up the environment only partially when running aliases, and then
> the resulting command ends up confused about where the worktree is. I
> really don't remember the specifics, but you can probably find some
> discussion in the list archives.  Fixing it, IIRC, required some
> refactoring of the setup code (which I had hoped to get to at some
> point, but I am way behind on my git todo list).

The attached patch fixes the bug for me. I'll leave it to others to determine whether this is a good way to fix the problem.

Thanks, Geoffrey

From ec47aa09e5bc8d9a8c07cca9f8ef17a9898819c1 Mon Sep 17 00:00:00 2001
From: Geoffrey Irving <irving@naml.us>
Date: Mon, 10 Aug 2009 15:59:21 -0400
Subject: [PATCH] setup.c: fix work tree setup for .git-files and aliases

When .git-files and aliases are used together, the setup machinery gets confused and ends up with the wrong work_tree. Specifically, git_work_tree_cfg is set to the correct value first, but set_work_tree resets git_work_tree_cfg to the current directory, which (at least in this case) is incorrect.

set_work_tree now detects this case by checking to see if git_work_tree_cfg is already set. If so, it leaves git_work_tree_cfg unchanged and instead uses the current directory to compute and return the correct prefix (where we are relative to the work tree).

Signed-off-by: Geoffrey Irving <irving@naml.us>
---
 setup.c |   15 +++++++++++++--
 1 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/setup.c b/setup.c
index e3781b6..97f7eb1 100644
--- a/setup.c
+++ b/setup.c
@@ -198,13 +198,24 @@ int is_inside_work_tree(void)
 static const char *set_work_tree(const char *dir)
 {
 	char buffer[PATH_MAX + 1];
+	size_t offset;
 
 	if (!getcwd(buffer, sizeof(buffer)))
 		die ("Could not get the current working directory");
-	git_work_tree_cfg = xstrdup(buffer);
 	inside_work_tree = 1;
 
-	return NULL;
+	if (!git_work_tree_cfg) {
+		git_work_tree_cfg = xstrdup(buffer);
+		return NULL;
+	} else {
+		offset = strlen(git_work_tree_cfg);
+		if (memcmp(git_work_tree_cfg, buffer, offset)
+			|| (buffer[offset] && buffer[offset] != '/'))
+			die ("fatal: not inside work tree (should not happen)");
+		if (!buffer[offset] || !buffer[offset+1])
+			return NULL;
+		return xstrdup(strcat(buffer + offset + 1, "/"));
+	}
 }
 
 void setup_work_tree(void)

-- 
1.6.3.3