Re: [PATCH] unpack-trees.c: assume submodules are clean during check-out
- From
Junio C Hamano <gitster@pobox.com>
- Date
- Aug 4, 2007, 05:13 UTC
- Message-ID
- <7v643vj316.fsf@assigned-by-dhcp.cox.net>
- In-Reply-To
- <20070801140532.GC31114MdfPADPa@greensroom.kotnet.org>
Sven Verdoolaege <skimo@kotnet.org> writes:
Show 15 quoted lines
> If you have a submodule checked out and you go back (or forward) > to a revision of the supermodule that contains a different > revision of the submodule and then switch to another revision, > it will complain that the submodule is not uptodate, because > git simply didn't update the submodule in the first move. > > Now, you may say that I simply need to run 'git submodule update' > after every such move, but this is very inconvenient, especially > if you're doing a bisect or a rebase. > > How do other people deal with this problem? > > How about just replacing the body of ce_compare_gitlink > with "return 0" until git actually (optionally) updates > the submodules during an update of the supermodule?
Let me understand the problem first. If your first checkout does not check out the submodule, switching between revisions that has different commit of the submodule there would not fail, but once you checkout the submodule, switching without updating the submodule would be Ok (because by design updating the submodule is optional) but then further switching out of that state will fail because submodule in the supermodule tree and checked-out submodule repository are now out of sync. Is that the problem?
In any case, I doubt ce_compare_gitlink() is the right layer to work this around -- it is not about "can we switch" but is about "is it different". It is at too low a level.
The current policy is to consider it is perfectly normal that checked-out submodule is out-of-sync wrt the supermodule index, if I am reading you right. I think it is a good policy, at least until we introduce a superproject repository configuration option that says "in this repository, I do care about this submodule and at any time I move around in the superproject, recursively check out the submodule to match". The most extreme case of this policy is that the superproject index knows about the submodule but the subdirectory does not even have to be checked out, which is what we have now.
Where does the "No you are not up-to-date, I wouldn't let you switch" come from? Is that verify_uptodate() called from merged_entry() called from twoway_merge()? I think the right approach to deal with this is to teach verify_uptodate() about the policy. The function is about "make sure the filesystem entity that corresponds to this cache entry is up to date, lest we lose the local modifications". As we explicitly allow submodule checkout to drift from the supermodule index entry, the check should say "Ok, for submodules, not matching is the norm" for now. Later when we have the ability to mark "I care about this submodule to be always in sync with the superproject" (thereby implementing automatic recursive checkout and perhaps diff, among other things), we should check if the submodule in question is marked as such and perform the current test.
How about doing something like this instead?
unpack-trees.c | 9 +++++++++ 1 files changed, 9 insertions(+), 0 deletions(-)
diff --git a/unpack-trees.c b/unpack-trees.c index 3b32718..dfd985b 100644 --- a/unpack-trees.c +++ b/unpack-trees.c @@ -407,6 +407,15 @@ static void verify_uptodate(struct cache_entry *ce, unsigned changed = ce_match_stat(ce, &st, 1); if (!changed) return; + /* + * NEEDSWORK: the current default policy is to allow + * submodule to be out of sync wrt the supermodule + * index. This needs to be tightened later for + * submodules that are marked to be automatically + * checked out. + */ + if (S_ISGITLINK(ntohl(ce->ce_mode))) + return; errno = 0; } if (errno == ENOENT)