view tests/test-mq-qgoto.t @ 43913:4b7d5d10c45d

exchange: ensure all outgoing subrepo references are present before pushing

We've run into occasional problems with people committing a repo, and then
amending or rebasing in the subrepo.  That makes it so that the revision in the
parent can't be checked out, and the problem gets propagated on push.  Mercurial
already tries to defend against this sort of dangling reference by pushing *all*
subrepo revisions first.  This reuses the checks that trigger warnings in
`hg verify` to bail on the push unless using `--force`.

I thought about putting this on the server side, but at that point, all of the
data has been transferred, only to bail out.  Additionally, SCM Manager hosts
subrepos in a location that isn't nested in the parent, so normal subrepo code
would complain that the subrepo is missing when run on the server.

Because the push command pushes subrepos before calling this exchange code, a
subrepo will be pushed before the parent is verified.  Not great, but no
dangling references are exchanged, so it solves the problem.  This code isn't in
the loop that pushes the subrepos because:

  1) the list of outgoing revisions is needed to limit the scope of the check
  2) the loop only accesses the current revision, and therefore can miss
     subrepos that were dropped in previous commits
  3) this code is called when pushing a subrepo, so the protection is recursive

I'm not sure if there's a cheap check for the list of files in the outgoing
bundle.  If there is, that would provide a fast path to bypass this check for
people not using subrepos (or if no subrepo changes were made).  There's
probably also room for verifying other references like tags.  But since that
doesn't break checkouts, it's much less of a problem.

Differential Revision: https://phab.mercurial-scm.org/D7616

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init a
  $ cd a
  $ echo a > a
  $ hg ci -Ama
  adding a

  $ hg qnew a.patch
  $ echo a >> a
  $ hg qrefresh

  $ hg qnew b.patch
  $ echo b > b
  $ hg add b
  $ hg qrefresh

  $ hg qnew c.patch
  $ echo c > c
  $ hg add c
  $ hg qrefresh

  $ hg qgoto a.patch
  popping c.patch
  popping b.patch
  now at: a.patch

  $ hg qgoto c.patch
  applying b.patch
  applying c.patch
  now at: c.patch

  $ hg qgoto b.patch
  popping c.patch
  now at: b.patch

Using index:

  $ hg qgoto 0
  popping b.patch
  now at: a.patch

  $ hg qgoto 2
  applying b.patch
  applying c.patch
  now at: c.patch

No warnings when using index ... and update from non-qtip and with pending
changes in unrelated files:

  $ hg qnew bug314159
  $ echo d >> c
  $ hg qrefresh
  $ hg qnew bug141421
  $ echo e >> b
  $ hg qrefresh

  $ hg up -r bug314159
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo f >> a
  $ echo f >> b
  $ echo f >> c

  $ hg qgoto 1
  abort: local changes found, qrefresh first
  [255]
  $ hg qgoto 1 -f
  popping bug141421
  popping bug314159
  popping c.patch
  now at: b.patch
  $ hg st
  M a
  M b
  ? c.orig
  $ hg up -qCr.

  $ hg qgoto 3
  applying c.patch
  applying bug314159
  now at: bug314159

Detect ambiguous non-index:

  $ hg qgoto 14
  patch name "14" is ambiguous:
    bug314159
    bug141421
  abort: patch 14 not in series
  [255]

  $ cd ..