Hi Junio, On Tue, Apr 21, 2020 at 01:41:56PM -0700, Junio C Hamano wrote: > Taylor Blau <me@xxxxxxxxxxxx> writes: > > > In bd0b42aed3 (fetch-pack: do not take shallow lock unnecessarily, > > 2019-01-10), the author noted that 'is_repository_shallow' produces > > visible side-effect(s) by setting 'is_shallow' and 'shallow_stat'. > > > > This is a problem for e.g., fetching with '--update-shallow' in a > > shallow repsoitory with 'fetch.writeCommitGraph' enabled, since the > > repository. Whoops, sorry about that. > > update to '.git/shallow' will cause Git to think that the repository > > isn't shallow when it is, thereby circumventing the commit-graph > > compatability check. > > > > This causes problems in shallow repositories with at least shallow refs > > that have at least one ancestor (since the client won't have those > > objects, and therefore can't take the reachability closure over commits > > when writing a commit-graph). > > OK. > > > Address this by introducing 'reset_repository_shallow()', and calling > > it whenever the shallow files is updated. This happens in two cases: > > > > * during 'update_shallow', when either the repository is > > un-shallowing, or after commit_lock_file, when the contents of > > .git/shallow is changing, and > > > > * in 'prune_shallow', when the repository can go from shallow to > > un-shallow when the shallow file is updated, forcing > > 'is_repository_shallow' to re-evaluate whether the repository is > > still shallow after fetching in the above scenario. > > > > As a result of the second change, 'prune_shallow' can now only be called > > once (since 'check_shallow_file_for_update' will die after calling > > 'reset_repository_shallow'). But, this is OK since we only call > > 'prune_shallow' at most once per process. > > > > Helped-by: Jonathan Tan <jonathantanmy@xxxxxxxxxx> > > Signed-off-by: Taylor Blau <me@xxxxxxxxxxxx> > > --- > > > > Here's a cleaned up version of the patch that we were originally > > discussing in > > https://lore.kernel.org/git/20200414235057.GA6863@syl.local/, which > > addresses some of Jonathan's feedback and adds a test to make sure that > > the new behavior is working correctly. > > > > commit.h | 1 + > > fetch-pack.c | 1 + > > shallow.c | 15 ++++++++------- > > t/t5537-fetch-shallow.sh | 36 ++++++++++++++++++++++++++++++++++++ > > 4 files changed, 46 insertions(+), 7 deletions(-) > > > > diff --git a/commit.h b/commit.h > > index 008a0fa4a0..ee1ba139d4 100644 > > --- a/commit.h > > +++ b/commit.h > > @@ -251,6 +251,7 @@ int register_shallow(struct repository *r, const struct object_id *oid); > > int unregister_shallow(const struct object_id *oid); > > int for_each_commit_graft(each_commit_graft_fn, void *); > > int is_repository_shallow(struct repository *r); > > +void reset_repository_shallow(struct repository *r); > > struct commit_list *get_shallow_commits(struct object_array *heads, > > int depth, int shallow_flag, int not_shallow_flag); > > struct commit_list *get_shallow_commits_by_rev_list( > > diff --git a/fetch-pack.c b/fetch-pack.c > > index 1734a573b0..684868bc17 100644 > > --- a/fetch-pack.c > > +++ b/fetch-pack.c > > @@ -1632,6 +1632,7 @@ static void update_shallow(struct fetch_pack_args *args, > > rollback_lock_file(&shallow_lock); > > } else > > commit_lock_file(&shallow_lock); > > + reset_repository_shallow(the_repository); > > alternate_shallow_file = NULL; > > return; > > } > > So, after updating shallow file with "fetch --update-shallow" (or > failing to do so), we reset the in-core data. > > > +void reset_repository_shallow(struct repository *r) > > +{ > > + r->parsed_objects->is_shallow = -1; > > + stat_validity_clear(r->parsed_objects->shallow_stat); > > +} > > OK. > > > @@ -362,6 +361,7 @@ void setup_alternate_shallow(struct lock_file *shallow_lock, > > * shallow file". > > */ > > *alternate_shallow_file = ""; > > + reset_repository_shallow(the_repository); > > strbuf_release(&sb); > > } > > And also after writing out the alternate shallow file (whether it is > empty or polulated). > > > @@ -414,6 +414,7 @@ void prune_shallow(unsigned options) > > } else { > > unlink(git_path_shallow(the_repository)); > > rollback_lock_file(&shallow_lock); > > + reset_repository_shallow(the_repository); > > } > > Here, we reset only after we realize we cannot write the updated > shallow file. Intended? Yes, see this earlier discussion I had about it with Jonathan: https://lore.kernel.org/git/20200416020509.225014-1-jonathantanmy@xxxxxxxxxx/. > > + cat <<EOF >expect.refs && > > +refs/remotes/shallow/master > > +refs/remotes/shallow/no-shallow > > +refs/tags/heavy-tag > > +refs/tags/heavy-tag-for-graph > > +refs/tags/light-tag > > +refs/tags/light-tag-for-graph > > +EOF > > cat <<-EOF >expect.refs && > ... body can be indented by any number of TAB > ... to make it easier to view > EOF > > > + test_cmp expect.refs actual.refs && > > + git log --format=%s shallow/master >actual && > > + cat <<EOF >expect && > > Likewise. I'd be happy to update these, but I am matching the (poor) style of the surrounding tests. Are you OK with the inconsistency? Would you like another preparatory patch to clean up the surrounding? Thanks, Taylor
