On Sat, Dec 15, 2018 at 05:05:08PM -0800, Erin Dahlgren wrote:
> setup_git_directory_gently() expects two types of failures to
> discover a git directory (e.g. .git/):
> [...]
When I read your subject line, I'll admit to having a funny feeling in
the pit of my stomach. This setup code has historically been full of
subtle corner cases, and I expected a very tricky review.
However, your explanation was so well-written that it was a pleasure to
read. :)
> Before this change are two misleading additional behaviors:
>
> - GIT_DIR_HIT_CEILING: setup_nongit() changes to the cwd for no
> apparent reason. We never had the chance to change directories
> up to this point so chdir(current cwd) is pointless.
That makes sense. I think this is a holdover from when we used to walk
backwards via chdir(), prior to ce9b8aab5d (setup_git_directory_1():
avoid changing global state, 2017-03-13). Back then, we needed to
restore the state at this point, but now we don't.
> - GIT_DIR_HIT_MOUNT_POINT: strbuf_release() frees the buffer
> of a static struct strbuf (cwd). This is unnecessary because the
> struct is static so its buffer is always reachable. This is also
> misleading because nowhere else in the function is this buffer
> released.
Makes sense.
I do have one question, though:
> case GIT_DIR_HIT_CEILING:
> - prefix = setup_nongit(cwd.buf, nongit_ok);
> - break;
> + if (!nongit_ok)
> + die(_("not a git repository (or any of the parent directories): %s"),
>a + DEFAULT_GIT_DIR_ENVIRONMENT);
> + *nongit_ok = 1;
> + strbuf_release(&dir);
> + return NULL;
This case used to break out of the switch, and now returns early.
So we do not execute the later code which clears GIT_PREFIX_ENVIRONMENT,
and zeroes the fields in startup_info. Those probably don't matter in
most cases, but I wonder if there are some obscure ones where it might.
Might it make sense to make GIT_DIR_HIT_MOUNT_POINT more like
GIT_DIR_HIT_CEILING currently is, rather than the other way around?
I.e., something like:
case GIT_DIR_HIT_CEILING:
if (!nongit_ok)
die(...);
*nongit_ok = 1;
prefix = NULL;
break;
case GIT_DIR_HIT_MOUNT_POINT:
if (!nongit_ok)
die(...);
*nongit_ok = 1;
prefix = NULL;
break;
?
-Peff
