read-cache: make `do_read_index()` always set up `istate->repo`

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> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Martin Ågren committed Jul 22, 2022 at 23:22 UTC 4447d4129d944eb136fd5c35014cc2b370a2d752
2 files changed +9 -1
read-cache.c
+4 -1
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); }
t/t7063-status-untracked-cache.sh
+5
index 9936cc329e..c1f0d95036 100755 --- a/t/t7063-status-untracked-cache.sh +++ b/t/t7063-status-untracked-cache.sh @@ -985,4 +985,9 @@ 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 && + git -C emptyrepo -c core.untrackedCache=true write-tree +' + test_done