Hi,
On Wed, 6 Feb 2008, Johannes Sixt wrote:
> Jeff King schrieb:
> > 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():
-- snip --
cd /git
cat > a1.c << EOF
#include <stdio.h>
#include "compat/setenv.c"
#include "compat/unsetenv.c"
static void p()
{
const char *abc = getenv("ABC");
printf("env ABC: %s\n", abc ? abc : "(null)");
}
int main()
{
p();
gitsetenv("ABC", "Hello", 1);
p();
gitsetenv("ABC", "", 1);
p();
gitunsetenv("ABC");
p();
return 0;
}
EOF
gcc -DNO_MMAP=1 -I. -Icompat -o a1.exe a1.c
ABC="" ./a1.exe
-- snap --
This will show
env ABC:
env ABC: Hello
env ABC: (null)
env ABC: (null)
So it seems that environment variables _can_ be empty. Just our
relatively stupid implementation of setenv() does not do it.
Maybe something like compat/unsetenv.c is needed in setenv(), too.
Ciao,
Dscho
-
To unsubscribe from this list: send the line "unsubscribe git" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
