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
$ hg init
$ echo a > a
$ hg ci -Am0
adding a
$ hg -q clone . foo
$ touch .hg/store/journal
$ echo foo > a
$ hg ci -Am0
abort: abandoned transaction found!
(run 'hg recover' to clean up transaction)
[255]
$ hg recover
rolling back interrupted transaction
(verify step skipped, run `hg verify` to check your repository content)
recover, explicit verify
$ touch .hg/store/journal
$ hg ci -Am0
abort: abandoned transaction found!
(run 'hg recover' to clean up transaction)
[255]
$ hg recover --verify
rolling back interrupted transaction
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 1 changesets with 1 changes to 1 files
recover, no verify
$ touch .hg/store/journal
$ hg ci -Am0
abort: abandoned transaction found!
(run 'hg recover' to clean up transaction)
[255]
$ hg recover --no-verify
rolling back interrupted transaction
(verify step skipped, run `hg verify` to check your repository content)
Check that zero-size journals are correctly aborted:
#if unix-permissions no-root
$ hg bundle -qa repo.hg
$ chmod -w foo/.hg/store/00changelog.i
$ hg -R foo unbundle repo.hg
adding changesets
abort: Permission denied: '$TESTTMP/foo/.hg/store/.00changelog.i-*' (glob)
[255]
$ if test -f foo/.hg/store/journal; then echo 'journal exists :-('; fi
#endif