Re: [PATCH v2] fsck: handle NULL return of lookup_blob() and lookup_tree()

René Scharfe [off-list ref] writes:

An error message is already shown by object_as_type(), which is called
by the lookup functions.  The walk callback functions are expected to
handle NULL object pointers passed to them, but put_object_name() needs
a valid object, so avoid calling it without one.

Thanks for getting the details right ;-)

+	blob_bin=$(echo $blob | hex2oct) &&
+	tree=$(
+		printf "40000 dir\0${blob_bin}100644 file\0${blob_bin}" |

Wow, that's ... cute.

+		git hash-object -t tree --stdin -w --literally

Makes me curious why --literally is here.  Even if we let
check_tree() called from index_mem() by taking the normal path,
it wouldn't complain the type mismatch, I suspect.  I guess doing it
this way is a future-proof against check_tree() getting tightened in
the future, in which case I think it makes sense.

And for the same reason, hashing "--literally" like this patch does
is a better solution than using "git mktree", which would have
allowed us to avoid the hex2oct and instead feed the tree in a bit
more human-readable way.

Thanks, will queue.

+	) &&
+	commit=$(git commit-tree $tree) &&
+	git update-ref refs/heads/type_mismatch $commit &&
+	test_must_fail git fsck >out 2>&1 &&
+	test_i18ngrep "is a blob, not a tree" out &&
+	test_i18ngrep ! "dangling blob" out
+'
+
 test_expect_success 'tag pointing to nonexistent' '
 	cat >invalid-tag <<-\EOF &&
 	object ffffffffffffffffffffffffffffffffffffffff

Am 06.10.2017 um 04:23 schrieb Junio C Hamano:

René Scharfe [off-list ref] writes:

quoted

+	blob_bin=$(echo $blob | hex2oct) &&
+	tree=$(
+		printf "40000 dir\0${blob_bin}100644 file\0${blob_bin}" |

Wow, that's ... cute.

quoted

+		git hash-object -t tree --stdin -w --literally

Makes me curious why --literally is here.  Even if we let
check_tree() called from index_mem() by taking the normal path,
it wouldn't complain the type mismatch, I suspect.  I guess doing it
this way is a future-proof against check_tree() getting tightened in
the future, in which case I think it makes sense.

And for the same reason, hashing "--literally" like this patch does
is a better solution than using "git mktree", which would have
allowed us to avoid the hex2oct and instead feed the tree in a bit
more human-readable way.

git mktree errors out already, complaining about the object type
mismatch.  But I added "--literally" only accidentally, when I copied
the invocation from a few lines up.  The test works fine without that
flag currently.  The flag captures the intent, however, of knowingly
building a flawed tree object.

René