fsck: verify commit graph when implicitly enabled

Change fsck to check the "core_commit_graph" variable set in
"repo-settings.c" instead of reading the "core.commitGraph" variable.
This fixes a bug where we wouldn't verify the commit-graph if the
config key was missing. This bug was introduced in
31b1de6a09 (commit-graph: turn on commit-graph by default, 2019-08-13),
where core.commitGraph was turned on by default.

Add tests to "t5318-commit-graph.sh" to verify that fsck checks the
commit-graph as expected for the 3 values of core.commitGraph. Also,
disable GIT_TEST_COMMIT_GRAPH in t/t0410-partial-clone.sh because some
test cases use fsck in ways that assume that commit-graph checking is
disabled.

Helped-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Glen Choo <chooglen@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

1 files changed, 5 insertions, 1 deletions

diff --git a/t/t0410-partial-clone.sh b/t/t0410-partial-clone.sh
index bba679685f..c76485b1b6 100755
--- a/t/t0410-partial-clone.sh
+++ b/t/t0410-partial-clone.sh
@@ -6,6 +6,10 @@ test_description='partial clone'
 
 # missing promisor objects cause repacks which write bitmaps to fail
 GIT_TEST_MULTI_PACK_INDEX_WRITE_BITMAP=0
+# When enabled, some commands will write commit-graphs. This causes fsck
+# to fail when delete_object() is called because fsck will attempt to
+# verify the out-of-sync commit graph.
+GIT_TEST_COMMIT_GRAPH=0
 
 delete_object () {
 	rm $1/.git/objects/$(echo $2 | sed -e 's|^..|&/|')
@@ -322,7 +326,7 @@ test_expect_success 'rev-list stops traversal at missing and promised commit' '
 
 	git -C repo config core.repositoryformatversion 1 &&
 	git -C repo config extensions.partialclone "arbitrary string" &&
-	GIT_TEST_COMMIT_GRAPH=0 git -C repo -c core.commitGraph=false rev-list --exclude-promisor-objects --objects bar >out &&
+	git -C repo rev-list --exclude-promisor-objects --objects bar >out &&
 	grep $(git -C repo rev-parse bar) out &&
 	! grep $FOO out
 '