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.
$ . "$TESTDIR/histedit-helpers.sh"
$ cat >> $HGRCPATH <<EOF
> [extensions]
> histedit=
> EOF
$ initrepo ()
> {
> hg init r
> cd r
> for x in a b c d e f ; do
> echo $x > $x
> hg add $x
> hg ci -m $x
> done
> echo a >> e
> hg ci -m 'does not commute with e'
> cd ..
> }
$ initrepo
$ cd r
log before edit
$ hg log --graph
@ changeset: 6:bfa474341cc9
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: does not commute with e
|
o changeset: 5:652413bf663e
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:e860deea161a
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:055a42cdd887
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:177f92b77385
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
edit the history
$ hg histedit 177f92b77385 --commands - 2>&1 <<EOF | fixbundle
> pick 177f92b77385 c
> pick 055a42cdd887 d
> pick bfa474341cc9 does not commute with e
> pick e860deea161a e
> pick 652413bf663e f
> EOF
merging e
warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
Fix up the change (pick e860deea161a)
(hg histedit --continue to resume)
insert unsupported advisory merge record
$ hg --config extensions.fakemergerecord=$TESTDIR/fakemergerecord.py fakemergerecord -x
$ hg debugmergestate
local (already edited): 8f7551c7e4a2f2efe0bc8c741baf7f227d65d758
other (current change): e860deea161a2f77de56603b340ebbb4536308ae
file: e (state "u")
local path: e (hash 58e6b3a414a1e090dfc6029add0f3555ccba127f, flags "")
ancestor path: e (node 0000000000000000000000000000000000000000)
other path: e (node 6b67ccefd5ce6de77e7ead4f5292843a0255329f)
extra: ancestorlinknode = 0000000000000000000000000000000000000000
extra: merged = yes
$ hg resolve -l
U e
insert unsupported mandatory merge record
$ hg --config extensions.fakemergerecord=$TESTDIR/fakemergerecord.py fakemergerecord -X
$ hg debugmergestate
abort: unsupported merge state records: X
(see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
[255]
$ hg resolve -l
abort: unsupported merge state records: X
(see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
[255]
$ hg resolve -ma
abort: unsupported merge state records: X
(see https://mercurial-scm.org/wiki/MergeStateRecords for more information)
[255]
abort the edit (should clear out merge state)
$ hg histedit --abort 2>&1 | fixbundle
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg debugmergestate
no merge state found
log after abort
$ hg resolve -l
$ hg log --graph
@ changeset: 6:bfa474341cc9
| tag: tip
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: does not commute with e
|
o changeset: 5:652413bf663e
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: f
|
o changeset: 4:e860deea161a
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: e
|
o changeset: 3:055a42cdd887
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: d
|
o changeset: 2:177f92b77385
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: c
|
o changeset: 1:d2ae7f538514
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: b
|
o changeset: 0:cb9a9f314b8b
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: a
Early tree conflict doesn't leave histedit in a wedged state. Note
that we don't specify --commands here: we catch the problem before we
even prompt the user for rules, sidestepping any dataloss issues.
$ hg rm c
$ hg ci -m 'remove c'
$ echo collision > c
$ hg histedit e860deea161a
c: untracked file differs
abort: untracked files in working directory conflict with files in 055a42cdd887
[20]
We should have detected the collision early enough we're not in a
histedit state, and p1 is unchanged.
$ hg log -r 'p1()' -T'{node}\n'
1b0954ff00fccb15a37b679e4a35e9b01dfe685e
$ hg status --config ui.tweakdefaults=yes
? c
? e.orig
$ cd ..