Commit 4cf67869b2 ("list-objects.c: don't segfault for missing cmdline
objects", 2018-12-06) prevented some segmentation faults from occurring
by tightening handling of missing objects provided through the CLI: if
--ignore-missing is set, then it is OK (and the missing object ignored,
just like one would if encountered in traversal).
However, in the case that --ignore-missing is not set but
--exclude-promisor-objects is set, there is still no distinction between
the case wherein the missing object is a promisor object and the case
wherein it is not. This is unnecessarily restrictive, since if a missing
promisor object is encountered in traversal, it is ignored; likewise it
should be ignored if provided through the CLI. Therefore, distinguish
between these 2 cases. (As a bonus, the code is now simpler.)
(Note that this only affects handling of missing promisor objects.
Handling of non-missing promisor objects is already done by setting all
of them to UNINTERESTING in prepare_revision_walk().)
Additionally, clarify in get_reference() that error messages are already
being printed by the functions called (parse_object(),
repo_parse_commit(), and parse_commit_buffer() - invoked by the latter).
Signed-off-by: Jonathan Tan <jonathantanmy@xxxxxxxxxx>
---
Changes from v1: Improved code comments and commit message
> This is the case where oid must be COMMIT from oid_object_info()'s
> point of view, but repo_parse_commit() finds it as a non-commit, and
> object becomes NULL. This is quite different from the normal lazy
> clone case where exclude-promisor-objects etc. wants to cover, that
> the object whose name is oid is truly missing because it can be
> fetched later from elsewhere. Instead, we have found that there is
> an inconsistency in the data we have about the object, iow, a
> possible corruption.
Thanks! I should have looked at the first half of get_reference() more
carefully.
If there is corruption in the form of hash mismatch, parse_object() will
print a message and then return NULL, leaving get_reference() to handle
it - and treat it as missing in this case. It seems reasonable to me to
handle the repo_parse_commit() failure in a similar way. I've added
comments to clarify that error messages are being printed.
---
revision.c | 23 ++++++++++++++++++++++-
t/t0410-partial-clone.sh | 10 ++--------
2 files changed, 24 insertions(+), 9 deletions(-)
diff --git a/revision.c b/revision.c
index 8136929e23..af1e31b4fc 100644
--- a/revision.c
+++ b/revision.c
@@ -370,8 +370,18 @@ static struct object *get_reference(struct rev_info *revs, const char *name,
if (!repo_parse_commit(revs->repo, c))
object = (struct object *) c;
else
+ /*
+ * There is something wrong with the commit.
+ * repo_parse_commit() will have already printed an
+ * error message. For our purposes, treat as missing.
+ */
object = NULL;
} else {
+ /*
+ * There is something wrong with the object. parse_object()
+ * will have already printed an error message. For our
+ * purposes, treat as missing.
+ */
object = parse_object(revs->repo, oid);
}
@@ -1907,7 +1917,18 @@ int handle_revision_arg(const char *arg_, struct rev_info *revs, int flags, unsi
verify_non_filename(revs->prefix, arg);
object = get_reference(revs, arg, &oid, flags ^ local_flags);
if (!object)
- return revs->ignore_missing ? 0 : -1;
+ /*
+ * If this object is corrupt, get_reference() prints an error
+ * message and treats it as missing.
+ *
+ * get_reference() returns NULL only if this object is missing
+ * and ignore_missing is true, or this object is a (missing)
+ * promisor object and exclude_promisor_objects is true. In
+ * both these cases, we can safely ignore this object because
+ * this object will not appear in output and cannot be used as
+ * a source of UNINTERESTING ancestors (since it is missing).
+ */
+ return 0;
add_rev_cmdline(revs, object, arg_, REV_CMD_REV, flags ^ local_flags);
add_pending_object_with_path(revs, object, arg, oc.mode, oc.path);
free(oc.path);
diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index a3988bd4b8..fd28f5402a 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -416,15 +416,9 @@ test_expect_success 'rev-list dies for missing objects on cmd line' '
git -C repo config extensions.partialclone "arbitrary string" &&
for OBJ in "$COMMIT" "$TREE" "$BLOB"; do
- test_must_fail git -C repo rev-list --objects \
+ git -C repo rev-list --objects \
--exclude-promisor-objects "$OBJ" &&
- test_must_fail git -C repo rev-list --objects-edge-aggressive \
- --exclude-promisor-objects "$OBJ" &&
-
- # Do not die or crash when --ignore-missing is passed.
- git -C repo rev-list --ignore-missing --objects \
- --exclude-promisor-objects "$OBJ" &&
- git -C repo rev-list --ignore-missing --objects-edge-aggressive \
+ git -C repo rev-list --objects-edge-aggressive \
--exclude-promisor-objects "$OBJ"
done
'
--
2.24.1.735.g03f4e72817-goog
