import-checker: establish modern import convention
We introduce a new convention for declaring imports and enforce it via
the import checker script.
The new convention is only active when absolute imports are used, which is
currently nowhere. Keying off "from __future__ import absolute_import" to
engage the new import convention seems like the easiest solution. It is
also beneficial for Mercurial to use this mode because it means less work
and ambiguity for the importer and potentially better performance due to
fewer stat() system calls because the importer won't look for modules in
relative paths unless explicitly asked.
Once all files are converted to use absolute import, we can refactor
this code to again only have a single import convention and we can
require use of absolute import in the style checker.
The rules for the new convention are documented in the docstring of the
added function. Tests have been added to test-module-imports.t. Some
tests are sensitive to newlines and source column position, which makes
docstring testing difficult and/or impossible.
Criss cross merging
$ hg init criss-cross
$ cd criss-cross
$ echo '0 base' > f1
$ echo '0 base' > f2
$ hg ci -Aqm '0 base'
$ echo '1 first change' > f1
$ hg ci -m '1 first change f1'
$ hg up -qr0
$ echo '2 first change' > f2
$ hg ci -qm '2 first change f2'
$ hg merge -qr 1
$ hg ci -m '3 merge'
$ hg up -qr2
$ hg merge -qr1
$ hg ci -qm '4 merge'
$ echo '5 second change' > f1
$ hg ci -m '5 second change f1'
$ hg up -r3
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo '6 second change' > f2
$ hg ci -m '6 second change f2'
$ hg log -G
@ changeset: 6:3b08d01b0ab5
| tag: tip
| parent: 3:cf89f02107e5
| user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: 6 second change f2
|
| o changeset: 5:adfe50279922
| | user: test
| | date: Thu Jan 01 00:00:00 1970 +0000
| | summary: 5 second change f1
| |
| o changeset: 4:7d3e55501ae6
| |\ parent: 2:40663881a6dd
| | | parent: 1:0f6b37dbe527
| | | user: test
| | | date: Thu Jan 01 00:00:00 1970 +0000
| | | summary: 4 merge
| | |
o---+ changeset: 3:cf89f02107e5
| | | parent: 2:40663881a6dd
|/ / parent: 1:0f6b37dbe527
| | user: test
| | date: Thu Jan 01 00:00:00 1970 +0000
| | summary: 3 merge
| |
| o changeset: 2:40663881a6dd
| | parent: 0:40494bf2444c
| | user: test
| | date: Thu Jan 01 00:00:00 1970 +0000
| | summary: 2 first change f2
| |
o | changeset: 1:0f6b37dbe527
|/ user: test
| date: Thu Jan 01 00:00:00 1970 +0000
| summary: 1 first change f1
|
o changeset: 0:40494bf2444c
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: 0 base
$ hg merge -v --debug --tool internal:dump 5 --config merge.preferancestor='!'
note: using 0f6b37dbe527 as ancestor of 3b08d01b0ab5 and adfe50279922
alternatively, use --config merge.preferancestor=40663881a6dd
searching for copies back to rev 3
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: 0f6b37dbe527, local: 3b08d01b0ab5+, remote: adfe50279922
preserving f2 for resolve of f2
f1: remote is newer -> g
getting f1
f2: versions differ -> m
picked tool 'internal:dump' for f2 (binary False symlink False)
merging f2
my f2@3b08d01b0ab5+ other f2@adfe50279922 ancestor f2@40494bf2444c
1 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
$ head *
==> f1 <==
5 second change
==> f2 <==
6 second change
==> f2.base <==
0 base
==> f2.local <==
6 second change
==> f2.orig <==
6 second change
==> f2.other <==
2 first change
$ hg up -qC .
$ hg merge -v --tool internal:dump 5 --config merge.preferancestor="null 40663881 3b08d"
note: using 40663881a6dd as ancestor of 3b08d01b0ab5 and adfe50279922
alternatively, use --config merge.preferancestor=0f6b37dbe527
resolving manifests
merging f1
0 files updated, 0 files merged, 0 files removed, 1 files unresolved
use 'hg resolve' to retry unresolved file merges or 'hg update -C .' to abandon
[1]
Redo merge with merge.preferancestor="*" to enable bid merge
$ rm f*
$ hg up -qC .
$ hg merge -v --debug --tool internal:dump 5 --config merge.preferancestor="*"
note: merging 3b08d01b0ab5+ and adfe50279922 using bids from ancestors 0f6b37dbe527 and 40663881a6dd
calculating bids for ancestor 0f6b37dbe527
searching for copies back to rev 3
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: 0f6b37dbe527, local: 3b08d01b0ab5+, remote: adfe50279922
f1: remote is newer -> g
f2: versions differ -> m
calculating bids for ancestor 40663881a6dd
searching for copies back to rev 3
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: 40663881a6dd, local: 3b08d01b0ab5+, remote: adfe50279922
f1: versions differ -> m
f2: remote unchanged -> k
auction for merging merge bids
f1: picking 'get' action
f2: picking 'keep' action
end of auction
f1: remote is newer -> g
getting f1
f2: remote unchanged -> k
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ head *
==> f1 <==
5 second change
==> f2 <==
6 second change
The other way around:
$ hg up -C -r5
2 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg merge -v --debug --config merge.preferancestor="*"
note: merging adfe50279922+ and 3b08d01b0ab5 using bids from ancestors 0f6b37dbe527 and 40663881a6dd
calculating bids for ancestor 0f6b37dbe527
searching for copies back to rev 3
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: 0f6b37dbe527, local: adfe50279922+, remote: 3b08d01b0ab5
f1: remote unchanged -> k
f2: versions differ -> m
calculating bids for ancestor 40663881a6dd
searching for copies back to rev 3
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: 40663881a6dd, local: adfe50279922+, remote: 3b08d01b0ab5
f1: versions differ -> m
f2: remote is newer -> g
auction for merging merge bids
f1: picking 'keep' action
f2: picking 'get' action
end of auction
f2: remote is newer -> g
getting f2
f1: remote unchanged -> k
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ head *
==> f1 <==
5 second change
==> f2 <==
6 second change
Verify how the output looks and and how verbose it is:
$ hg up -qC
$ hg merge
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg up -qC
$ hg merge -v
note: merging 3b08d01b0ab5+ and adfe50279922 using bids from ancestors 0f6b37dbe527 and 40663881a6dd
calculating bids for ancestor 0f6b37dbe527
resolving manifests
calculating bids for ancestor 40663881a6dd
resolving manifests
auction for merging merge bids
f1: picking 'get' action
f2: picking 'keep' action
end of auction
getting f1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg up -qC
$ hg merge -v --debug --config merge.preferancestor="*"
note: merging 3b08d01b0ab5+ and adfe50279922 using bids from ancestors 0f6b37dbe527 and 40663881a6dd
calculating bids for ancestor 0f6b37dbe527
searching for copies back to rev 3
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: 0f6b37dbe527, local: 3b08d01b0ab5+, remote: adfe50279922
f1: remote is newer -> g
f2: versions differ -> m
calculating bids for ancestor 40663881a6dd
searching for copies back to rev 3
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: 40663881a6dd, local: 3b08d01b0ab5+, remote: adfe50279922
f1: versions differ -> m
f2: remote unchanged -> k
auction for merging merge bids
f1: picking 'get' action
f2: picking 'keep' action
end of auction
f1: remote is newer -> g
getting f1
f2: remote unchanged -> k
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ cd ..
http://stackoverflow.com/questions/9350005/how-do-i-specify-a-merge-base-to-use-in-a-hg-merge/9430810
$ hg init ancestor-merging
$ cd ancestor-merging
$ echo a > x
$ hg commit -A -m a x
$ hg update -q 0
$ echo b >> x
$ hg commit -m b
$ hg update -q 0
$ echo c >> x
$ hg commit -qm c
$ hg update -q 1
$ hg merge -q --tool internal:local 2
$ echo c >> x
$ hg commit -m bc
$ hg update -q 2
$ hg merge -q --tool internal:local 1
$ echo b >> x
$ hg commit -qm cb
$ hg merge --config merge.preferancestor='!'
note: using 70008a2163f6 as ancestor of 0d355fdef312 and 4b8b546a3eef
alternatively, use --config merge.preferancestor=b211bbc6eb3c
merging x
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ cat x
a
c
b
c
$ hg up -qC .
$ hg merge --config merge.preferancestor=b211bbc6eb3c
note: using b211bbc6eb3c as ancestor of 0d355fdef312 and 4b8b546a3eef
alternatively, use --config merge.preferancestor=70008a2163f6
merging x
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ cat x
a
b
c
b
$ hg up -qC .
$ hg merge -v --config merge.preferancestor="*"
note: merging 0d355fdef312+ and 4b8b546a3eef using bids from ancestors 70008a2163f6 and b211bbc6eb3c
calculating bids for ancestor 70008a2163f6
resolving manifests
calculating bids for ancestor b211bbc6eb3c
resolving manifests
auction for merging merge bids
x: multiple bids for merge action:
versions differ -> m
versions differ -> m
x: ambiguous merge - picked m action
end of auction
merging x
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ cat x
a
c
b
c
Verify that the old context ancestor works with / despite preferancestor:
$ hg log -r 'ancestor(head())' --config merge.preferancestor=1 -T '{rev}\n'
1
$ hg log -r 'ancestor(head())' --config merge.preferancestor=2 -T '{rev}\n'
2
$ hg log -r 'ancestor(head())' --config merge.preferancestor=3 -T '{rev}\n'
1
$ hg log -r 'ancestor(head())' --config merge.preferancestor='1337 * - 2' -T '{rev}\n'
2
$ cd ..