list-objects.c: handle unexpected non-blob entries

Fix one of the cases described in the previous commit where a tree-entry that is promised to a blob is in fact a non-blob. When 'lookup_blob()' returns NULL, it is because Git has cached the requested object as a non-blob. In this case, prevent a SIGSEGV by 'die()'-ing immediately before attempting to dereference the result. Signed-off-by: Taylor Blau <me@ttaylorr.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>

Taylor Blau committed Apr 9, 2019 at 19:13 UTC 23c204455bf2198806e8c7b0cd86b20a50a379d0
2 files changed +8 -2
list-objects.c
+5
@@ -133,6 +133,11 @@ static void process_tree_contents(struct traversal_context *ctx,
133 base, entry.path);
134 else {
135 struct blob *b = lookup_blob(ctx->revs->repo, &entry.oid);
136 + if (!b) {
137 + die(_("entry '%s' in tree %s has blob mode, "
138 + "but is not a blob"),
139 + entry.path, oid_to_hex(&tree->object.oid));
140 + }
141 b->object.flags |= NOT_USER_GIVEN;
142 process_blob(ctx, b, base, entry.path);
143 }
t/t6102-rev-list-unexpected-objects.sh
+3 -2
@@ -20,8 +20,9 @@ test_expect_failure 'traverse unexpected non-blob entry (lone)' '
20 test_must_fail git rev-list --objects $broken_tree
21 '
22
23 -test_expect_failure 'traverse unexpected non-blob entry (seen)' '
24 - test_must_fail git rev-list --objects $tree $broken_tree
23 +test_expect_success 'traverse unexpected non-blob entry (seen)' '
24 + test_must_fail git rev-list --objects $tree $broken_tree >output 2>&1 &&
25 + test_i18ngrep "is not a blob" output
26 '
27
28 test_expect_success 'setup unexpected non-tree entry' '