corruption: backout changeset 49fd21f32695 (issue6528)
inverting the parent is masking copy information leading to bad content being
fetched and bad status result.
Since 49fd21f32695, exchange can actively swap these parent corrupting existing
changesets and triggering the corruption.
Data corruption are considered critical so backing this out and doing and
unscheduled release seems in order.
Differential Revision: https://phab.mercurial-scm.org/D10995
Corrupt an hg repo with a pull started during an aborted commit
Create two repos, so that one of them can pull from the other one.
$ hg init source
$ cd source
$ touch foo
$ hg add foo
$ hg ci -m 'add foo'
$ hg clone . ../corrupted
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo >> foo
$ hg ci -m 'change foo'
Add a hook to wait 5 seconds and then abort the commit
$ cd ../corrupted
$ echo "[hooks]" >> .hg/hgrc
$ echo 'pretxncommit = sh -c "sleep 5; exit 1"' >> .hg/hgrc
start a commit...
$ touch bar
$ hg add bar
$ hg ci -m 'add bar' &
... and start a pull while the commit is still running
$ sleep 1
$ hg pull ../source 2>/dev/null
pulling from ../source
transaction abort!
rollback completed
abort: pretxncommit hook exited with status 1
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 52998019f625
(run 'hg update' to get a working copy)
see what happened
$ wait
$ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
checked 2 changesets with 2 changes to 1 files
$ cd ..