[PATCH 2 of 2] requires: write requires file on commit

[Adrian Buehlmann]

On 2015-05-04 20:27, Drew Gottlieb wrote:
> # HG changeset patch
> # User Drew Gottlieb <drgott at google.com>
> # Date 1429641493 25200
> #      Tue Apr 21 11:38:13 2015 -0700
> # Node ID 85c369520dd97bad369a0c4b924597f9e720077b
> # Parent  3f86e3b2548def52732e1f782e89297db8075e8b
> requires: write requires file on commit
> 
> Writing the requires file on commit makes it possible for changes to a
> repo's config to enable features that affect the repo's requirements. An
> example of this would be enabling manifestv2 in the future, which would then
> have future commits be written with the new manifest format, making it
> necessary for the requires file to indicate this.
> 
> This change also modifies test-inherit-mode to expect the requires file's
> mode to inherit from the store's mode after a commit. Previously, it only
> inherited from the store's mode on repo init, and the test assumed it would
> never be touched after this point.
> 
> diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
> --- a/mercurial/localrepo.py
> +++ b/mercurial/localrepo.py
> @@ -1602,6 +1602,7 @@
>                  #
>                  # if minimal phase was 0 we don't need to retract anything
>                  phases.retractboundary(self, tr, targetphase, [n])
> +            self._writerequirements()
>              tr.close()
>              branchmap.updatecache(self.filtered('served'))
>              return n
> diff --git a/tests/test-inherit-mode.t b/tests/test-inherit-mode.t
> --- a/tests/test-inherit-mode.t
> +++ b/tests/test-inherit-mode.t
> @@ -70,7 +70,7 @@
>    00660 ./.hg/cache/rbc-revs-v1
>    00660 ./.hg/dirstate
>    00660 ./.hg/last-message.txt
> -  00600 ./.hg/requires
> +  00660 ./.hg/requires
>    00770 ./.hg/store/
>    00660 ./.hg/store/00changelog.i
>    00660 ./.hg/store/00manifest.i

This sounds pretty scary...

I think repository readers today can safely assume that the requires
file is not changed any more after they have first seen it. Somebody
might be actually doing that already and indeed depend on that assumption.

At least, this might be quite a big surprise.