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.
$ cat <<'EOF' >> "$HGRCPATH"
> [extensions]
> convert =
> [templates]
> l = '{rev}:{node|short} p={p1rev},{p2rev} m={manifest} f={files|json}'
> EOF
$ check_convert_identity () {
> hg convert -q "$1" "$1.converted"
> hg outgoing -q -R "$1.converted" "$1"
> if [ "$?" != 1 ]; then
> echo '*** BUG: hash changes on convert ***'
> hg log -R "$1.converted" -GTl
> fi
> }
Files added at both parents:
$ hg init added-both
$ cd added-both
$ touch a b c
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ hg ci -qAm2 c
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
committing files:
b
not reusing manifest (no file change in changelog, but manifest differs)
committing manifest
committing changelog
updating the branch cache
committed changeset 3:7aa8a293f5d97377037afc21e871e036e718d659
$ hg log -GTl
@ 3:7aa8a293f5d9 p=2,1 m=3:8667461869a1 f=[]
|\
| o 2:e0ea47086fce p=0,-1 m=2:b2e5b07f9374 f=["c"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ cd ..
$ check_convert_identity added-both
Files added at both parents, but the other removed at the merge:
(In this case, ctx.files() after the commit contains the removed file "b", but
its manifest does not differ from p1.)
$ hg init added-both-removed-at-merge
$ cd added-both-removed-at-merge
$ touch a b c
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ hg ci -qAm2 c
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg rm -f b
$ hg ci --debug -m merge
committing files:
committing manifest
committing changelog
updating the branch cache
committed changeset 3:915745f3ca3d9d699925269474c2d0a9526e8dfa
$ hg log -GTl
@ 3:915745f3ca3d p=2,1 m=3:8e9cf3456921 f=["b"]
|\
| o 2:e0ea47086fce p=0,-1 m=2:b2e5b07f9374 f=["c"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ cd ..
$ check_convert_identity added-both
An identical file added at both parents:
$ hg init added-identical
$ cd added-identical
$ touch a b
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ touch b
$ hg ci -qAm2 b
$ hg merge
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
reusing manifest from p1 (no file change)
committing changelog
updating the branch cache
committed changeset 3:de26182cd210f0c3fb175ca7616704ab963d3024
$ hg log -GTl
@ 3:de26182cd210 p=2,1 m=1:686dbf0aeca4 f=[]
|\
| o 2:f00991f11eca p=0,-1 m=1:686dbf0aeca4 f=["b"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ cd ..
$ check_convert_identity added-identical
#if execbit
An identical file added at both parents, but the flag differs. Take local:
$ hg init flag-change-take-p1
$ cd flag-change-take-p1
$ touch a b
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ touch b
$ chmod +x b
$ hg ci -qAm2 b
$ hg merge
warning: cannot merge flags for b without common ancestor - keeping local flags
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ chmod +x b
$ hg ci --debug -m merge
committing files:
b
reusing manifest from p1 (listed files actually unchanged)
committing changelog
updating the branch cache
committed changeset 3:c8d50407916ef8a5a97cb6e36ca9bc844a6ee13e
$ hg log -GTl
@ 3:c8d50407916e p=2,1 m=2:36b69ba4b24b f=[]
|\
| o 2:99451f16b3f5 p=0,-1 m=2:36b69ba4b24b f=["b"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ hg files -vr3
0 a
0 x b
$ cd ..
$ check_convert_identity flag-change-take-p1
An identical file added at both parents, but the flag differs. Take other:
$ hg init flag-change-take-p2
$ cd flag-change-take-p2
$ touch a b
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ touch b
$ chmod +x b
$ hg ci -qAm2 b
$ hg merge
warning: cannot merge flags for b without common ancestor - keeping local flags
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ chmod -x b
$ hg ci --debug -m merge
committing files:
b
committing manifest
committing changelog
updating the branch cache
committed changeset 3:06a62a687d87c7d8944743dee1ee9d8c66b3f6e3
$ hg log -GTl
@ 3:06a62a687d87 p=2,1 m=3:2a315ba1aa45 f=["b"]
|\
| o 2:99451f16b3f5 p=0,-1 m=2:36b69ba4b24b f=["b"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ hg files -vr3
0 a
0 b
$ cd ..
$ check_convert_identity flag-change-take-p2
#endif
An identical file added at both parents, one more file added at p2:
$ hg init added-some-p2
$ cd added-some-p2
$ touch a b c
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg ci -qAm2 c
$ hg up -q 0
$ touch b
$ hg ci -qAm3 b
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
committing files:
c
not reusing manifest (no file change in changelog, but manifest differs)
committing manifest
committing changelog
updating the branch cache
committed changeset 4:f7fbc4e4d9a8fde03ba475adad675578c8bf472d
$ hg log -GTl
@ 4:f7fbc4e4d9a8 p=3,2 m=3:92acd5bfd716 f=[]
|\
| o 3:e9d9f3cc981f p=0,-1 m=1:686dbf0aeca4 f=["b"]
| |
o | 2:93c5529a4ec7 p=1,-1 m=2:ae25a31b30b3 f=["c"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ cd ..
$ check_convert_identity added-some-p2
An identical file added at both parents, one more file added at p1:
(In this case, p1 manifest is reused at the merge commit, which means the
manifest DAG does not have the same shape as the changelog.)
$ hg init added-some-p1
$ cd added-some-p1
$ touch a b
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ touch b c
$ hg ci -qAm2 b
$ hg ci -qAm3 c
$ hg merge
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
reusing manifest from p1 (no file change)
committing changelog
updating the branch cache
committed changeset 4:a9f0f589a913f5a149dc10dfbd5af726977c36c4
$ hg log -GTl
@ 4:a9f0f589a913 p=3,1 m=2:ae25a31b30b3 f=[]
|\
| o 3:b8dc385241b5 p=2,-1 m=2:ae25a31b30b3 f=["c"]
| |
| o 2:f00991f11eca p=0,-1 m=1:686dbf0aeca4 f=["b"]
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"]
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"]
$ cd ..
$ check_convert_identity added-some-p1
A file added at p2, a named branch created at p1:
$ hg init named-branch-p1
$ cd named-branch-p1
$ touch a b
$ hg ci -qAm0 a
$ hg ci -qAm1 b
$ hg up -q 0
$ hg branch -q foo
$ hg ci -m2
$ hg merge default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
committing files:
b
not reusing manifest (no file change in changelog, but manifest differs)
committing manifest
committing changelog
updating the branch cache
committed changeset 3:fb97d83b02fd072295cfc2171f21b7d38509bfd7
$ hg log -GT'{l} branch={branch}'
@ 3:fb97d83b02fd p=2,1 m=2:9091c64f4ea1 f=[] branch=foo
|\
| o 2:a3a9fa6587e5 p=0,-1 m=0:8515d4bfda76 f=[] branch=foo
| |
o | 1:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"] branch=default
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"] branch=default
$ cd ..
$ check_convert_identity named-branch-p1
A file added at p1, a named branch created at p2:
(In this case, p1 manifest is reused at the merge commit, which means the
manifest DAG does not have the same shape as the changelog.)
$ hg init named-branch-p2
$ cd named-branch-p2
$ touch a b
$ hg ci -qAm0 a
$ hg branch -q foo
$ hg ci -m1
$ hg up -q 0
$ hg ci -qAm1 b
$ hg merge foo
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
reusing manifest from p1 (no file change)
committing changelog
updating the branch cache
committed changeset 3:036823e24692218324d4af43b07ff89f8a000096
$ hg log -GT'{l} branch={branch}'
@ 3:036823e24692 p=2,1 m=1:686dbf0aeca4 f=[] branch=default
|\
| o 2:64d01526d4c2 p=0,-1 m=1:686dbf0aeca4 f=["b"] branch=default
| |
o | 1:da38c8e00727 p=0,-1 m=0:8515d4bfda76 f=[] branch=foo
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"] branch=default
$ cd ..
$ check_convert_identity named-branch-p2
A file changed once at both parents, but amended to have identical content:
$ hg init amend-p1
$ cd amend-p1
$ touch a
$ hg ci -qAm0 a
$ echo foo > a
$ hg ci -m1
$ hg up -q 0
$ echo bar > a
$ hg ci -qm2
$ echo foo > a
$ hg ci -qm3 --amend
$ hg merge
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci --debug -m merge
reusing manifest from p1 (no file change)
committing changelog
updating the branch cache
committed changeset 3:314e5bc5adf5c58ea571efabe33eedba20a201aa
$ hg log -GT'{l} branch={branch}'
@ 3:314e5bc5adf5 p=2,1 m=1:d33ea248bd73 f=[] branch=default
|\
| o 2:de9c64f226a3 p=0,-1 m=1:d33ea248bd73 f=["a"] branch=default
| |
o | 1:6a74aec01b3c p=0,-1 m=1:d33ea248bd73 f=["a"] branch=default
|/
o 0:487a0a245cea p=-1,-1 m=0:8515d4bfda76 f=["a"] branch=default
$ cd ..
$ check_convert_identity amend-p1