checkheads: upgrade the obsolescence postprocessing logic (issue4354)
The previous logic had many shortcoming (eg: looking at the head only, not
handling prune, etc...), the new logic use a more robust approach:
For each head, we check if after the push all changesets exclusive to this heads
will be obsolete. If they are, the branch considered be "replaced".
To check if a changeset will be obsolete, we simply checks:
* the changeset phase
* the existence of a marker relevant to the "pushed set" that affects the
changesets..
This fixes two major issues of the previous algorithm:
* branch partially rewritten (eg: head but not root) are no longer detected as
replaced,
* Prune are now properly handled.
(This implementation was introduction in the evolve extension, version 6.0.0.)
This new algorithm has an extended number of tests, a basic one is provided
in this patch. The others will be introduced in their own changeset for clarity.
In addition, we stop trying to process heads unknown locally, we do not have
enough data to take an informed decision so we should stop pretending we do.
This reflect a test that is now update.
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
(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
1 files, 2 changesets, 2 total revisions
$ cd ..