Am 04.10.2017 um 06:00 schrieb Junio C Hamano: > René Scharfe <l.s.r@xxxxxx> writes: >> lookup_blob() and lookup_tree() can return NULL if they find an object >> of an unexpected type. Error out of fsck_walk_tree() in that case, like >> we do when encountering a bad file mode. An error message is already >> shown by object_as_type(), which gets called by the lookup functions. > > The result from options->walk() is checked, and among the callbacks > that are assigned to the .walk field: > > - mark_object() in builtin/fsck.c gives its own error message to diagnose broken link > and returns 1; > > - mark_used() in builtin/fsck.c silently returns 1; > > - mark_link() in builtin/index-pack.c does the same; and > > - check_object() in builtin/unpack-objects.c does the same, > > when they see a NULL object. > > This patch may avoid the "unexpected behaviour" coming from > expecting that &((struct tree *)NULL)->object == NULL the current > code does, but it also changes the behaviour. The loop used to > diagnose a fishy entry in the tree we are walking, and kept checking > the remaining entries in the tree. You now immediately return, not > seeing if the later entries in the tree are good and losing objects > that are referenced by these entries as dangling. > > I am not sure if this is a good change. I suspect that the "bad > mode" handling should be made less severe instead. Makes sense. Replacement patch coming up. I'll pass on the mode handling change, though (at least for now). René
