[PATCH] read-cache: make `do_read_index()` always set up `istate->repo`
On Fri, 22 Jul 2022 at 21:41, Junio C Hamano <gitster@pobox.com> wrote:
Show 13 quoted lines
>
> Martin Ågren <martin.agren@gmail.com> writes:
>
> > I can't help but think that e6a653554b was just unlucky enough to
> > dereference `istate->repo` and that the real issue is that we're missing
> >
> > if (!istate->repo)
> > istate->repo = the_repository;
> >
> > in some strategic place a fair bit earlier. It seems to me like the diff
>
> Perhaps backtrace to see where the istate came from would quickly
> reveal where the real issue lies?
Here's an attempt at finding a proper spot for such a check. We end up with a small amount of duplicated code, but I think it should be ok, especially for a bugfix.
This is on top of tk/untracked-cache-with-uall and conflicts with 491df5f679 ("read-cache: set sparsity when index is new", 2022-05-10). The conflict could be resolved by taking my hunk before Victoria's [after which her helper function could be simplified accordingly] -- at least that passes all the tests.
I'm a bit out of my depth here. Hopefully one of the area experts can say more about this approach.
Martin
-- >8 --
If there is no index file, e.g., because the repository has just been created, we return zero early (unless `must_exist` makes us die instead.)
This early return means we do not set up `istate->repo`. With `core.untrackedCache=true`, the recent e6a653554b ("untracked-cache: support '--untracked-files=all' if configured", 2022-03-31) will eventually pass down `istate->repo` as a null pointer to `repo_config_get_string()`, causing a segmentation fault.
If we do hit this early return, set up `istate->repo` similar to when we actually read the index.
Reported-by: Joey Hess <id@joeyh.name>
Signed-off-by: Martin Ågren <martin.agren@gmail.com>
---
read-cache.c | 5 ++++-
t/t7063-status-untracked-cache.sh | 6 ++++++
2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/read-cache.c b/read-cache.c
index 3e0e7d4183..68ed65035b 100644
--- a/read-cache.c
+++ b/read-cache.c
@@ -2268,8 +2268,11 @@ int do_read_index(struct index_state *istate, const char *path, int must_exist)
istate->timestamp.nsec = 0;
fd = open(path, O_RDONLY);
if (fd < 0) {
- if (!must_exist && errno == ENOENT)
+ if (!must_exist && errno == ENOENT) {
+ if (!istate->repo)
+ istate->repo = the_repository;
return 0;
+ }
die_errno(_("%s: index file open failed"), path);
}
diff --git a/t/t7063-status-untracked-cache.sh b/t/t7063-status-untracked-cache.sh
index 9936cc329e..7dc5631f3d 100755
--- a/t/t7063-status-untracked-cache.sh
+++ b/t/t7063-status-untracked-cache.sh
@@ -985,4 +985,10 @@ test_expect_success '"status" after file replacement should be clean with UC=fal
status_is_clean
'
+test_expect_success 'empty repo (no index) and core.untrackedCache' '
+ git init emptyrepo &&
+ cd emptyrepo/ &&
+ git -c core.untrackedCache=true write-tree
+'
+
test_done
--
2.37.1.455.g008518b4e5
Joey Hess