When we have a .midx that covers many packfiles, we try to avoid opening
the .idx for those packfiles. However, there are a few problems with the
filename comparison we use:
- we ask midx_contains_pack() about the .pack name, not the .idx name.
But it compares to the latter.
- we compute the basename of the pack using strrchr() to find the
final slash. But that leaves an extra "/" at the start of our
string; we need to advance past it.
That also raises the question of what to do when the name does not
have a slash at all. This should generally not happen (we always
find files in "pack/"), but it doesn't hurt to be defensive here.
The tests don't notice because there's nothing about opening those .idx
files that would cause us to give incorrect output. It's just a little
slower. The new test checks this case by corrupting the covered .idx,
and then making sure we don't complain about it.
Signed-off-by: Jeff King <peff@xxxxxxxx>
---
packfile.c | 17 ++++++++++++++---
t/t5319-multi-pack-index.sh | 14 ++++++++++++++
2 files changed, 28 insertions(+), 3 deletions(-)
diff --git a/packfile.c b/packfile.c
index 054269ae5d..e7ca135ed5 100644
--- a/packfile.c
+++ b/packfile.c
@@ -472,6 +472,16 @@ static unsigned int get_max_fd_limit(void)
#endif
}
+static const char *pack_basename(struct packed_git *p)
+{
+ const char *ret = strrchr(p->pack_name, '/');
+ if (ret)
+ ret = ret + 1; /* skip past slash */
+ else
+ ret = p->pack_name; /* we only have a base */
+ return ret;
+}
+
/*
* Do not call this directly as this leaks p->pack_fd on error return;
* call open_packed_git() instead.
@@ -486,15 +496,16 @@ static int open_packed_git_1(struct packed_git *p)
ssize_t read_result;
const unsigned hashsz = the_hash_algo->rawsz;
- if (!p->index_data) {
+ if (!p->index_data && the_repository->objects->multi_pack_index) {
struct multi_pack_index *m;
- const char *pack_name = strrchr(p->pack_name, '/');
+ char *idx_name = pack_name_to_idx(pack_basename(p));
for (m = the_repository->objects->multi_pack_index;
m; m = m->next) {
- if (midx_contains_pack(m, pack_name))
+ if (midx_contains_pack(m, idx_name))
break;
}
+ free(idx_name);
if (!m && open_pack_index(p))
return error("packfile %s index unavailable", p->pack_name);
diff --git a/t/t5319-multi-pack-index.sh b/t/t5319-multi-pack-index.sh
index 8c4d2bd849..1ebf19ec3c 100755
--- a/t/t5319-multi-pack-index.sh
+++ b/t/t5319-multi-pack-index.sh
@@ -117,6 +117,20 @@ test_expect_success 'write midx with one v2 pack' '
compare_results_with_midx "one v2 pack"
+test_expect_success 'corrupt idx not opened' '
+ idx=$(test-tool read-midx $objdir | grep "\.idx\$") &&
+ mv $objdir/pack/$idx backup-$idx &&
+ test_when_finished "mv backup-\$idx \$objdir/pack/\$idx" &&
+
+ # This is the minimum size for a sha-1 based .idx; this lets
+ # us pass perfunctory tests, but anything that actually opens and reads
+ # the idx file will complain.
+ test_copy_bytes 1064 <backup-$idx >$objdir/pack/$idx &&
+
+ git -c core.multiPackIndex=true rev-list --objects --all 2>err &&
+ test_must_be_empty err
+'
+
test_expect_success 'add more objects' '
for i in $(test_seq 6 10)
do
--
2.21.0.714.gd1be1d035b
