view tests/test-merge-halt.t @ 37212:f09a2eab11cf

server: add an error feedback mechanism for when the daemon fails to launch

There's a recurring problem on Windows where `hg serve -d` will randomly fail to
spawn a detached process.  The reason for the failure is completely hidden, and
it takes hours to get a single failure on my laptop.  All this does is redirect
stdout/stderr of the child to a file until the lock file is freed, and then the
parent dumps it out if it fails to spawn.

I chose to put the output into the lock file because that is always cleaned up.
There's no way to report errors after that anyway.  On Windows, killdaemons.py
is roughly `kill -9`, so this ensures that junk won't pile up.

This may end up being a case of EADDRINUSE.  At least that's what I saw spit out
a few times (among other odd errors and missing output on Windows).  But I also
managed to get the same thing on Fedora 26 by running test-hgwebdir.t with
--loop -j10 for several hours.  Running `netstat` immediately after killing that
run printed a wall of sockets in the TIME_WAIT state, which were gone a couple
seconds later.  I couldn't match up ports that failed, because --loop doesn't
print out the message about the port that was used.  So maybe the fix is to
rotate the use of HGPORT[12] in the tests.  But, let's collect some more data
first.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > [phases]
  > publish=False
  > [merge]
  > EOF

  $ hg init repo
  $ cd repo
  $ echo a > a
  $ echo b > b
  $ hg commit -qAm ab
  $ echo c >> a
  $ echo c >> b
  $ hg commit -qAm c
  $ hg up -q ".^"
  $ echo d >> a
  $ echo d >> b
  $ hg commit -qAm d

Testing on-failure=continue
  $ echo on-failure=continue >> $HGRCPATH
  $ hg rebase -s 1 -d 2 --tool false
  rebasing 1:1f28a51c3c9b "c"
  merging a
  merging b
  merging a failed!
  merging b failed!
  unresolved conflicts (see hg resolve, then hg rebase --continue)
  [1]

  $ hg resolve --list
  U a
  U b

  $ hg rebase --abort
  rebase aborted

Testing on-failure=halt
  $ echo on-failure=halt >> $HGRCPATH
  $ hg rebase -s 1 -d 2 --tool false
  rebasing 1:1f28a51c3c9b "c"
  merging a
  merging b
  merging a failed!
  merge halted after failed merge (see hg resolve)
  [1]

  $ hg resolve --list
  U a
  U b

  $ hg rebase --abort
  rebase aborted

Testing on-failure=prompt
  $ cat <<EOS >> $HGRCPATH
  > [merge]
  > on-failure=prompt
  > [ui]
  > interactive=1
  > EOS
  $ cat <<EOS | hg rebase -s 1 -d 2 --tool false
  > y
  > n
  > EOS
  rebasing 1:1f28a51c3c9b "c"
  merging a
  merging b
  merging a failed!
  continue merge operation (yn)? y
  merging b failed!
  continue merge operation (yn)? n
  merge halted after failed merge (see hg resolve)
  [1]

  $ hg resolve --list
  U a
  U b

  $ hg rebase --abort
  rebase aborted

Check that successful tool with failed post-check halts the merge
  $ cat <<EOS >> $HGRCPATH
  > [merge-tools]
  > true.check=changed
  > EOS
  $ cat <<EOS | hg rebase -s 1 -d 2 --tool true
  > y
  > n
  > n
  > EOS
  rebasing 1:1f28a51c3c9b "c"
  merging a
  merging b
   output file a appears unchanged
  was merge successful (yn)? y
   output file b appears unchanged
  was merge successful (yn)? n
  merging b failed!
  continue merge operation (yn)? n
  merge halted after failed merge (see hg resolve)
  [1]

  $ hg resolve --list
  R a
  U b

  $ hg rebase --abort
  rebase aborted

Check that conflicts with conflict check also halts the merge
  $ cat <<EOS >> $HGRCPATH
  > [merge-tools]
  > true.check=conflicts
  > true.premerge=keep
  > [merge]
  > on-failure=halt
  > EOS
  $ hg rebase -s 1 -d 2 --tool true
  rebasing 1:1f28a51c3c9b "c"
  merging a
  merging b
  merging a failed!
  merge halted after failed merge (see hg resolve)
  [1]

  $ hg resolve --list
  U a
  U b

  $ hg rebase --abort
  rebase aborted

Check that always-prompt also can halt the merge
  $ cat <<EOS | hg rebase -s 1 -d 2 --tool true --config merge-tools.true.check=prompt
  > y
  > n
  > EOS
  rebasing 1:1f28a51c3c9b "c"
  merging a
  merging b
  was merge of 'a' successful (yn)? y
  was merge of 'b' successful (yn)? n
  merging b failed!
  merge halted after failed merge (see hg resolve)
  [1]

  $ hg resolve --list
  R a
  U b

  $ hg rebase --abort
  rebase aborted

Check that successful tool otherwise allows the merge to continue
  $ hg rebase -s 1 -d 2 --tool echo --keep --config merge-tools.echo.premerge=keep
  rebasing 1:1f28a51c3c9b "c"
  merging a
  merging b
  $TESTTMP/repo/a *a~base* *a~other* (glob)
  $TESTTMP/repo/b *b~base* *b~other* (glob)