tests/test-issue1802.t

test: add test-transaction-rollback-on-sigpipe.t demonstrating py3 regression

When an hg push is interrupted with C-c, the remote [hg serve] command
receives SIGPIPE.

If a pretxnchangegroup hook fails, the remote hg then tries to
rollback the transaction. It begins by printing "transaction
abort!\n". This returns EPIPE, but ui.py ignores that error.

In python3 (but not python2), this "transaction abort!\n" message
stays in a buffer, so future flushes of stderr will try to print the
message again, and so those flushes will also hit EPIPE.

This test demonstrates such a case where this EPIPE causes the
transaction rollback to fail, leaving behind an abandoned transaction.

Differential Revision: https://phab.mercurial-scm.org/D9151

#require execbit

Create extension that can disable exec checks:

  $ cat > noexec.py <<EOF
  > from mercurial import extensions, util
  > def setflags(orig, f, l, x):
  >     pass
  > def checkexec(orig, path):
  >     return False
  > def extsetup(ui):
  >     extensions.wrapfunction(util, 'setflags', setflags)
  >     extensions.wrapfunction(util, 'checkexec', checkexec)
  > EOF

  $ hg init unix-repo
  $ cd unix-repo
  $ touch a
  $ hg add a
  $ hg commit -m 'unix: add a'
  $ hg clone . ../win-repo
  updating to branch default
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ chmod +x a
  $ hg commit -m 'unix: chmod a'
  $ hg manifest -v
  755 * a

  $ cd ../win-repo

  $ touch b
  $ hg add b
  $ hg commit -m 'win: add b'

  $ hg manifest -v
  644   a
  644   b

  $ hg pull
  pulling from $TESTTMP/unix-repo
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files (+1 heads)
  new changesets 2d8bcf2dda39
  (run 'hg heads' to see heads, 'hg merge' to merge)

  $ hg manifest -v -r tip
  755 * a

Simulate a Windows merge:

  $ hg --config extensions.n=$TESTTMP/noexec.py merge --debug
  resolving manifests
   branchmerge: True, force: False, partial: False
   ancestor: a03b0deabf2b, local: d6fa54f68ae1+, remote: 2d8bcf2dda39
   a: update permissions -> e
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

Simulate a Windows commit:

  $ hg --config extensions.n=$TESTTMP/noexec.py commit -m 'win: merge'

  $ hg manifest -v
  755 * a
  644   b

  $ cd ..