threads / bug / 55239

[BUG?] git submodule update --remote assumes 'origin' remote

Subject: [BUG?] git submodule update --remote assumes 'origin' remote

## tl;dr

4 messages between Mar 1, 2021 and Mar 1, 2021.

replies: 3people: 2as markdown or json

Sean Barag· Mar 1, 2021, 15:46 UTC · lore

I think I've found a bit of an edge case in `git submodule update --remote` [1] that got easier to reproduce in 2.30+ under certain configurations. `git submodule--helper print-default-remote` defaults to 'origin' when run in a submodule in a detached HEAD state or on a branch with no remote tracking branch [1]. In git < 2.30, the only way for that default to be incorrect required a user to manually change remote names with something like `git -C ./some-sm remote rename origin foo`. `git rev-parse`ing that ref would naturally fail, but at least it's because the user took manual steps to break git's assumptions.

Under git 2.30+ with clone.defaultRemoteName set however, submodules are created with that remote name instead of 'origin'. The same behavior occurs, but this time without direct user action - only a simple `git submodule init && git submodule update --remote` is required.

I'm terribly sorry about that regression - I've only just started working on a few projects that use submodules heavily and probably could have found this sooner. I'm happy to fix it, but would *super* appreciate a little guidance. It seems the intention is "use the remote that has the url found in the superproject's .submodules entry", that'd require `git submodule--helper print-default-remote` to be called from the superproject from what I can tell. I've experimented with introducing fallbacks to `remote_for_branch` in `remote.c` [2] as an alternative:

1. use remote tracking branch; or
2. if there's only one remote, use that; or
3. if config.defaultRemoteName is set, use that; or
4. fall back to "origin"

This seems to work (at the very least, no tests fail?), but leaves `cd ./some-sm; git remote add foo bar; git remote rename origin baz` open to the original behavior.

Something tells me y'all will have a very simple solution that I'm missing :)

Again, I'm so sorry for introducing a regression here! Sean Barag

[1] https://github.com/git/git/blob/225365fb5195e804274ab569ac3cc4919451dc7f/git-submodule.sh#L571-L584 [2] https://github.com/git/git/blob/225365fb5195e804274ab569ac3cc4919451dc7f/remote.c#L477-L487

Ævar Arnfjörð Bjarmason· Mar 1, 2021, 16:38 UTC · re: Sean Barag · lore

Re: [BUG?] git submodule update --remote assumes 'origin' remote

On Mon, Mar 01 2021, Sean Barag wrote:

Show 40 quoted lines

> I think I've found a bit of an edge case in
> `git submodule update --remote` [1] that got easier to reproduce in
> 2.30+ under certain configurations.
> `git submodule--helper print-default-remote` defaults to 'origin' when
> run in a submodule in a detached HEAD state or on a branch with no
> remote tracking branch [1].  In git < 2.30, the only way for that
> default to be incorrect required a user to manually change remote names
> with something like `git -C ./some-sm remote rename origin foo`.
> `git rev-parse`ing that ref would naturally fail, but at least it's
> because the user took manual steps to break git's assumptions.
>
> Under git 2.30+ with clone.defaultRemoteName set however, submodules are
> created with that remote name instead of 'origin'.  The same behavior
> occurs, but this time without direct user action - only a simple
> `git submodule init && git submodule update --remote` is required.
>
> I'm terribly sorry about that regression - I've only just started
> working on a few projects that use submodules heavily and probably could
> have found this sooner.  I'm happy to fix it, but would *super*
> appreciate a little guidance.  It seems the intention is "use the remote
> that has the url found in the superproject's .submodules entry", that'd
> require `git submodule--helper print-default-remote` to be called from
> the superproject from what I can tell.  I've experimented with
> introducing fallbacks to `remote_for_branch` in `remote.c` [2] as an
> alternative:
>
> 1. use remote tracking branch; or
> 2. if there's only one remote, use that; or
> 3. if config.defaultRemoteName is set, use that; or
> 4. fall back to "origin"
>
> This seems to work (at the very least, no tests fail?), but leaves
> `cd ./some-sm; git remote add foo bar; git remote rename origin baz`
> open to the original behavior.
>
> Something tells me y'all will have a very simple solution that I'm
> missing :)
>
> Again, I'm so sorry for introducing a regression here!
> Sean Barag

Just a quick note, I gather you're talking about de9ed3ef37 (clone: allow configurable default for `-o`/`--origin`, 2020-10-01) which was first released in v2.30.0.

Just noting that in the context of this bug already being in a release, since we're now in the 2.31.0-rc0 period. Meaning likely not a release blocker in the next few weeks.

Sean Barag· Mar 1, 2021, 17:13 UTC · re: Ævar Arnfjörð Bjarmason · lore

Re: [BUG?] git submodule update --remote assumes 'origin' remote

On Mon, Mar 1, 2021, at 8:38 AM, Ævar Arnfjörð Bjarmason wrote:

> Just a quick note, I gather you're talking about de9ed3ef37 (clone:
> allow configurable default for `-o`/`--origin`, 2020-10-01) which was
> first released in v2.30.0.

Yes, that's exactly the commit.  I knew I forgot to include something.

> Just noting that in the context of this bug already being in a
> release, since we're now in the 2.310-rc0 period. Meaning likely not
> a release blocker in the next few weeks.

That makes sense - thanks for clarifying!

Sean Barag· Mar 1, 2021, 17:17 UTC · re: Sean Barag · lore

Re: [BUG?] git submodule update --remote assumes 'origin' remote

On Mon, Mar 01 2021, Sean Barag wrote:

Show 12 quoted lines

> I've experimented with
> introducing fallbacks to `remote_for_branch` in `remote.c` [2] as an
> alternative:
> 
> 1. use remote tracking branch; or
> 2. if there's only one remote, use that; or
> 3. if config.defaultRemoteName is set, use that; or
> 4. fall back to "origin"
> 
> This seems to work (at the very least, no tests fail?), but leaves
> `cd ./some-sm; git remote add foo bar; git remote rename origin baz`
> open to the original behavior.

I forgot to mention that this approach requires `get_default_remote` in `submodule--helper.c` to use the name of the remote returned by `remote_get(NULL)`. That was probably obvious to regular mailing list readers :D