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 rep
$ cd rep
$ mkdir dir
$ touch foo dir/bar
$ hg -v addremove
adding dir/bar
adding foo
$ hg -v commit -m "add 1"
committing files:
dir/bar
foo
committing manifest
committing changelog
committed changeset 0:6f7f953567a2
$ cd dir/
$ touch ../foo_2 bar_2
$ hg -v addremove
adding dir/bar_2
adding foo_2
$ hg -v commit -m "add 2"
committing files:
dir/bar_2
foo_2
committing manifest
committing changelog
committed changeset 1:e65414bf35c5
$ cd ..
$ hg forget foo
$ hg -v addremove
adding foo
$ hg forget foo
$ hg -v addremove nonexistent
nonexistent: $ENOENT$
[1]
$ cd ..
$ hg init subdir
$ cd subdir
$ mkdir dir
$ cd dir
$ touch a.py
$ hg addremove 'glob:*.py'
adding a.py
$ hg forget a.py
$ hg addremove -I 'glob:*.py'
adding a.py
$ hg forget a.py
$ hg addremove
adding dir/a.py
$ cd ..
$ hg init sim
$ cd sim
$ echo a > a
$ echo a >> a
$ echo a >> a
$ echo c > c
$ hg commit -Ama
adding a
adding c
$ mv a b
$ rm c
$ echo d > d
$ hg addremove -n -s 50 # issue 1696
removing a
adding b
removing c
adding d
recording removal of a as rename to b (100% similar)
$ hg addremove -ns 50 --color debug
[ui.addremove.removed ui.status|removing a]
[ui.addremove.added ui.status|adding b]
[ui.addremove.removed ui.status|removing c]
[ui.addremove.added ui.status|adding d]
[ ui.status|recording removal of a as rename to b (100% similar)]
$ hg addremove -s 50
removing a
adding b
removing c
adding d
recording removal of a as rename to b (100% similar)
$ hg commit -mb
$ cp b c
$ hg forget b
$ hg addremove -s 50
adding b
adding c
$ rm c
$ hg ci -A -m "c" nonexistent
nonexistent: $ENOENT$
abort: failed to mark all new/missing files as added/removed
[255]
$ hg st
! c
$ cd ..