view tests/test-repair-strip.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

#require unix-permissions no-root reporevlogstore

  $ cat > $TESTTMP/dumpjournal.py <<EOF
  > import sys
  > for entry in sys.stdin.read().split('\n'):
  >     if entry:
  >         print(entry.split('\x00')[0])
  > EOF

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

  $ teststrip() {
  >   hg -q up -C $1
  >   echo % before update $1, strip $2
  >   hg parents
  >   chmod -$3 $4
  >   hg strip $2 2>&1 | sed 's/\(bundle\).*/\1/' | sed 's/Permission denied.*\.hg\/store\/\(.*\)/Permission denied \.hg\/store\/\1/'
  >   echo % after update $1, strip $2
  >   chmod +$3 $4
  >   hg verify
  >   echo % journal contents
  >   if [ -f .hg/store/journal ]; then
  >       cat .hg/store/journal | "$PYTHON" $TESTTMP/dumpjournal.py
  >   else
  >       echo "(no journal)"
  >   fi
  >   ls .hg/store/journal >/dev/null 2>&1 && hg recover
  >   ls .hg/strip-backup/* >/dev/null 2>&1 && hg unbundle -q .hg/strip-backup/*
  >   rm -rf .hg/strip-backup
  > }

  $ hg init test
  $ cd test
  $ echo a > a
  $ hg -q ci -m "a" -A
  $ echo b > b
  $ hg -q ci -m "b" -A
  $ echo b2 >> b
  $ hg -q ci -m "b2" -A
  $ echo c > c
  $ hg -q ci -m "c" -A
  $ teststrip 0 2 w .hg/store/data/b.i
  % before update 0, strip 2
  changeset:   0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  
  saved backup bundle
  transaction abort!
  failed to truncate data/b.i
  rollback failed - please run hg recover
  (failure reason: [Errno *] Permission denied .hg/store/data/b.i') (glob)
  strip failed, backup bundle
  abort: Permission denied .hg/store/data/b.i'
  % after update 0, strip 2
  abandoned transaction found - run hg recover
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
   b@?: rev 1 points to nonexistent changeset 2
   (expected 1)
   b@?: 736c29771fba not in manifests
  warning: orphan data file 'data/c.i'
  checked 2 changesets with 3 changes to 2 files
  2 warnings encountered!
  2 integrity errors encountered!
  % journal contents
  00changelog.i
  00manifest.i
  data/b.i
  data/c.i
  rolling back interrupted transaction
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 2 changes to 2 files
  $ teststrip 0 2 r .hg/store/data/b.i
  % before update 0, strip 2
  changeset:   0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  
  abort: Permission denied .hg/store/data/b.i'
  % after update 0, strip 2
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 4 changesets with 4 changes to 3 files
  % journal contents
  (no journal)
  $ teststrip 0 2 w .hg/store/00manifest.i
  % before update 0, strip 2
  changeset:   0:cb9a9f314b8b
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     a
  
  saved backup bundle
  transaction abort!
  failed to truncate 00manifest.i
  rollback failed - please run hg recover
  (failure reason: [Errno *] Permission denied .hg/store/00manifest.i') (glob)
  strip failed, backup bundle
  abort: Permission denied .hg/store/00manifest.i'
  % after update 0, strip 2
  abandoned transaction found - run hg recover
  checking changesets
  checking manifests
   manifest@?: rev 2 points to nonexistent changeset 2
   manifest@?: 3362547cdf64 not in changesets
   manifest@?: rev 3 points to nonexistent changeset 3
   manifest@?: 265a85892ecb not in changesets
  crosschecking files in changesets and manifests
   c@3: in manifest but not in changeset
  checking files
   b@?: rev 1 points to nonexistent changeset 2
   (expected 1)
   c@?: rev 0 points to nonexistent changeset 3
  checked 2 changesets with 4 changes to 3 files
  1 warnings encountered!
  7 integrity errors encountered!
  (first damaged changeset appears to be 3)
  % journal contents
  00changelog.i
  00manifest.i
  data/b.i
  data/c.i
  rolling back interrupted transaction
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 2 changesets with 2 changes to 2 files

  $ cd ..