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. > 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? > + 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.
