Re: [PATCH] allow setting GIT_WORK_TREE to "no work tree"

Hi,

On Fri, 8 Feb 2008, Johannes Sixt wrote:

Johannes Schindelin schrieb:

quoted

On Wed, 6 Feb 2008, Johannes Sixt wrote:

quoted

Jeff King schrieb:

quoted

In setup_git_directory_gently, we have a special rule that says "if 
GIT_DIR is set but GIT_WORK_TREE is not, then use the current 
working directory as the work tree." This is the intended behavior 
for the user perspective.

However, setup_git_directory_gently sets GIT_DIR itself, meaning 
that further setups (either because we are executing a command via 
alias, or in a subprocess) will see the non-existent GIT_WORK_TREE 
and assume we fall into the "current working directory is the 
working tree" codepath.

Instead, we now use a special value of GIT_WORK_TREE to indicate 
that we have already checked for a worktree and that there isn't 
one, setting it when we set GIT_DIR and checking for it in the 
special case path.

The special value is a blank GIT_WORK_TREE; it could be any value, 
but this should not conflict with any user values (and as a bonus, 
you can now tell git "I don't have a work tree" with "GIT_WORK_TREE= 
git", though I suspect the use case for that is limited).

Hrm. Unfortunately, on Windows there is no such thing as an empty 
environment string. setenv(x, "") *removes* the environment variable.

That might be a shortcoming of our implementation of setenv():

No, it is not. It's Windows's putenv(), and it's even documented.

Yes, that's what I said: our setenv() implementation uses putenv(), which 
introduces that bug (setenv() is not supposed to unset variables, 
unsetenv() is).

That said, we probably should modify environ directly in gitsetenv().

Exactly.

Ciao,
Dscho