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.
$ hg init
$ echo foo > a
$ hg add a
$ hg commit -m "1"
$ echo bar > b
$ hg add b
$ hg remove a
Should show a removed and b added:
$ hg status
A b
R a
$ hg revert --all
undeleting a
forgetting b
Should show b unknown and a back to normal:
$ hg status
? b
$ rm b
$ hg co -C 0
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo foo-a > a
$ hg commit -m "2a"
$ hg co -C 0
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo foo-b > a
$ hg commit -m "2b"
created new head
$ HGMERGE=true hg merge 1
merging a
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
Should show foo-b:
$ cat a
foo-b
$ echo bar > b
$ hg add b
$ rm a
$ hg remove a
Should show a removed and b added:
$ hg status
A b
R a
Revert should fail:
$ hg revert
abort: uncommitted merge with no revision specified
(use 'hg update' or see 'hg help revert')
[255]
Revert should be ok now:
$ hg revert -r2 --all
undeleting a
forgetting b
Should show b unknown and a marked modified (merged):
$ hg status
M a
? b
Should show foo-b:
$ cat a
foo-b