Subrepo status/diff/revert

[Tim Henigan]

Hello,

My team intends to use subrepos for shared modules in our products.
However, some concerns were raised about the current user interface.

Developers here are interested in a few key features:
    1) `hg status` must show when a subrepo has been modified (e.g.
updated to different changeset or locally modified).
    2) If a subrepo has been modified, then `hg diff` must show the
change to the SHA1 (or just append '+dirty' to the SHA1 if locally
modified).
    3) If a subrepo has been mistakenly modified, then `hg revert`
must update it to the correct changeset.
    4) The above changes must not break TortoiseHg.

I understand that changes to subrepo behavior are being considered [1]
[2], but I haven't seen anything yet that would address these needs.

With that in mind, I plan to develop an extension to:

    1) Modify `hg status` to show when a subrepo SHA1 does not match
the SHA1 in .hgsubstate.  My current plan is to output 'S subrepo/dir'
when a mismatch is found. This is the same action done in TortoiseHg
today.

    2) Modify `hg revert` to update subrepos to the SHA1 listed in .hgsubstate.

    3) Modify `hg diff` to show changes to the .hgsubstate SHA1.  This includes:
        a) Replacing the subrepo SHA1 in .hgsubstate if it does not match.
        b) Appending '+dirty' to the SHA1 in .hgsubstate if the
subrepo has local modifications.
        -) NOTE: I am not sure if modifying .hgsubstate is safe in this context.

Does this group of changes sound reasonable?
Are there other plans to develop similar features?

Thanks,
Tim Henigan

[1] http://mercurial.selenic.com/wiki/SubrepoRemappingPlan
[2] http://marc.info/?t=127589116200002&r=1&w=1