Junio C Hamano <gitster@xxxxxxxxx> writes:
> if (repo_get_oid_treeish(the_repository,
> default_attr_source_tree_object_name,
> attr_source) && !ignore_bad_attr_tree)
> die(_("bad --attr-source or GIT_ATTR_SOURCE"));
>
> OOPS! Sorry for not noticing earlier, but repo_get_oid_treeish()
> does *NOT* error out when the discovered object is not a treeish, as
> the suggested object type is merely supplied for disambiguation
> purposes (e.g., with objects 012345 that is a tree and 012346 that
> is a blob, you can still ask for treeish "01234" but if you ask for
> an object "01234" it will fail).
>
> So, the alternative test would have caught this bug, no? Instead of
> silently treating the non-treeish as an empty tree, we would have
> died much later when the object supposedly a tree-ish turns out to
> be a blob, or something?
There indeed is a bug, but not really. If we add this test:
test_expect_success 'attr.tree that points at a non-treeish' '
test_when_finished rm -rf empty &&
git init empty &&
(
cd empty &&
echo "f/path: test: unspecified" >expect &&
H=$(git hash-object -t blob --stdin -w </dev/null) &&
git -c attr.tree=$H check-attr test -- f/path >actual 2>err &&
test_must_be_empty err &&
test_cmp expect actual
)
'
repo_get_oid_treeish() returns a blob object name and we end up
storing a blob object name in "attr_source" static variable of
default_attr_source() function.
Later this is fed to read_attr() by bootstrap_attr_stack() and then
to read_attr_from_blob() that uses it to call get_tree_entry(),
which fails for any path because it is a blob. We do not give any
errors or error messages during the whole process.
So in a sense, for !!ignore_bad_attr_tree case, the code ends up
doing the right thing. But if !ignore_bad_attr_tree is true, i.e.,
a blob object name is given via --attr-source or GIT_ATTR_SOURCE,
then the bug will be uncovered.
t/t0003-attributes.sh | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git c/t/t0003-attributes.sh w/t/t0003-attributes.sh
index ecf43ab545..0f02f22171 100755
--- c/t/t0003-attributes.sh
+++ w/t/t0003-attributes.sh
@@ -394,6 +394,18 @@ test_expect_success 'bare repo defaults to reading .gitattributes from HEAD' '
test_cmp expect actual
'
+test_expect_success '--attr-source that points at a non-treeish' '
+ test_when_finished rm -rf empty &&
+ git init empty &&
+ (
+ cd empty &&
+ echo "$bad_attr_source_err" >expect_err &&
+ H=$(git hash-object -t blob --stdin -w </dev/null) &&
+ test_must_fail git --attr-source=$H check-attr test -- f/path 2>err &&
+ test_cmp expect_err err
+ )
+'
+
test_expect_success 'precedence of --attr-source, GIT_ATTR_SOURCE, then attr.tree' '
test_when_finished rm -rf empty &&
git init empty &&
