push: rework the computation of fallbackheads to be correct
The previous computation tried to be smart but ended up being wrong. This was
caught by phase movement test while reworking the phase discovery logic to be
faster.
The previous logic was failing to catch case where the pushed set was not based
on a common heads (i.e. when the discovery seemed to have "over discovered"
content, outside the pushed set)
In the following graph, `e` is a common head and we `hg push -r f`. We need to
detect `c` as a fallback heads and we previous failed to do so::
e
|
d f
|/
c
|
b
|
a
The performance impact of the change seems minimal. On the most impacted
repository at hand (mozilla-try), the slowdown seems mostly mixed in the
overall noise `hg push` but seems to be in the hundred of milliseconds order of
magnitude. When using rust, we seems to be a bit faster, probably because we
leverage more accelaratd internals.
I added a couple of performance related common for further investigation later
on.
$ hg init repo
$ cd repo
$ echo This is file a1 > a
$ hg add a
$ hg commit -m "commit #0"
$ echo This is file b1 > b
$ hg add b
$ hg commit -m "commit #1"
$ hg update 0
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo This is file c1 > c
$ hg add c
$ hg commit -m "commit #2"
created new head
$ hg merge 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ rm b
$ echo This is file c22 > c
Test hg behaves when committing with a missing file added by a merge
$ hg commit -m "commit #3"
abort: cannot commit merge with missing files
[255]
Test conflict*() revsets
# Bad usage
$ hg log -r 'conflictlocal(foo)'
hg: parse error: conflictlocal takes no arguments
[10]
$ hg log -r 'conflictother(foo)'
hg: parse error: conflictother takes no arguments
[10]
$ hg co -C .
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
# No merge parents when not merging
$ hg log -r 'conflictlocal() + conflictother()'
# No merge parents when there is no conflict
$ hg merge 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg log -r 'conflictlocal() + conflictother()'
$ hg co -C .
0 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ echo conflict > b
$ hg ci -Aqm 'conflicting change to b'
$ hg merge 1
merging b
warning: conflicts while merging b! (edit, then use 'hg resolve --mark')
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon
[1]
# Shows merge parents when there is a conflict
$ hg log -r 'conflictlocal()' -T '{rev} {desc}\n'
3 conflicting change to b
$ hg log -r 'conflictother()' -T '{rev} {desc}\n'
1 commit #1