filemerge: add support for partial conflict resolution by external tool
A common class of merge conflicts is in imports/#includes/etc. It's
relatively easy to write a tool that can resolve these conflicts,
perhaps by naively just unioning the statements and leaving any
cleanup to other tools to do later [1]. Such specialized tools cannot
generally resolve all conflicts in a file, of course. Let's therefore
call them "partial merge tools". Note that the internal simplemerge
algorithm is such a partial merge tool - one that only resolves
trivial "conflicts" where one side is unchanged or both sides change
in the same way.
One can also imagine having smarter language-aware partial tools that
merge the AST. It may be useful for such tools to interactively let
the user resolve any conflicts it can't resolve itself. However,
having the option of implementing it as a partial merge tool means
that the developer doesn't *need* to create a UI for it. Instead, the
user can resolve any remaining conflicts with their regular merge tool
(e.g. `:merge3` or `meld).
We don't currently have a way to let the user define such partial
merge tools. That's what this patch addresses. It lets the user
configure partial merge tools to run. Each tool can be configured to
run only on files matching certain patterns (e.g. "*.py"). The tool
takes three inputs (local, base, other) and resolves conflicts by
updating these in place. For example, let's say the inputs are these:
base:
```
import sys
def main():
print('Hello')
```
local:
```
import os
import sys
def main():
print('Hi')
```
other:
```
import re
import sys
def main():
print('Howdy')
```
A partial merge tool could now resolve the conflicting imports by
replacing the import statements in *all* files by the following
snippet, while leaving the remainder of the files unchanged.
```
import os
import re
import sys
```
As a result, simplemerge and any regular merge tool that runs after
the partial merge tool(s) will consider the imports to be
non-conflicting and will only present the conflict in `main()` to the
user.
Differential Revision: https://phab.mercurial-scm.org/D12356
$ hg init t
$ cd t
$ echo 1 > foo
$ hg ci -Am m
adding foo
$ cd ..
$ hg clone t tt
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd tt
$ echo 1.1 > foo
$ hg ci -Am m
$ cd ../t
$ echo 1.2 > foo
$ hg ci -Am m
Should respect config to disable dirty update
$ hg co -qC 0
$ echo 2 > foo
$ hg --config commands.update.check=abort pull -u ../tt
pulling from ../tt
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets 107cefe13e42
1 local changesets published
abort: uncommitted changes
[20]
$ hg --config extensions.strip= strip --no-backup tip
$ hg co -qC tip
Should not update to the other topological branch:
$ hg pull -u ../tt
pulling from ../tt
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets 107cefe13e42
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
updated to "800c91d5bfc1: m"
1 other heads for branch "default"
$ cd ../tt
Should not update to the other branch:
$ hg pull -u ../t
pulling from ../t
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
new changesets 800c91d5bfc1
1 local changesets published
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
updated to "107cefe13e42: m"
1 other heads for branch "default"
$ HGMERGE=true hg merge
merging foo
0 files updated, 1 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
$ hg ci -mm
$ cd ../t
Should work:
$ hg pull -u ../tt
pulling from ../tt
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (-1 heads)
new changesets 483b76ad4309
1 local changesets published
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
Similarity between "hg update" and "hg pull -u" in handling bookmark
====================================================================
Test that updating activates the bookmark, which matches with the
explicit destination of the update.
$ echo 4 >> foo
$ hg commit -m "#4"
$ hg bookmark active-after-pull
$ cd ../tt
(1) activating by --rev BOOKMARK
$ hg bookmark -f active-before-pull
$ hg bookmarks
* active-before-pull 3:483b76ad4309
$ hg pull -u -r active-after-pull
pulling from $TESTTMP/t
searching for changes
adding changesets
adding manifests
adding file changes
adding remote bookmark active-after-pull
added 1 changesets with 1 changes to 1 files
new changesets f815b3da6163
1 local changesets published
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark active-after-pull)
$ hg parents -q
4:f815b3da6163
$ hg bookmarks
* active-after-pull 4:f815b3da6163
active-before-pull 3:483b76ad4309
(discard pulled changes)
$ hg update -q 483b76ad4309
$ hg rollback -q
(2) activating by URL#BOOKMARK
$ hg bookmark -f active-before-pull
$ hg bookmarks
* active-before-pull 3:483b76ad4309
$ hg pull -u $TESTTMP/t#active-after-pull
pulling from $TESTTMP/t
searching for changes
adding changesets
adding manifests
adding file changes
adding remote bookmark active-after-pull
added 1 changesets with 1 changes to 1 files
new changesets f815b3da6163
1 local changesets published
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(activating bookmark active-after-pull)
$ hg parents -q
4:f815b3da6163
$ hg bookmarks
* active-after-pull 4:f815b3da6163
active-before-pull 3:483b76ad4309
(discard pulled changes)
$ hg update -q 483b76ad4309
$ hg rollback -q
Test that updating deactivates current active bookmark, if the
destination of the update is explicitly specified, and it doesn't
match with the name of any existing bookmarks.
$ cd ../t
$ hg bookmark -d active-after-pull
$ hg branch bar -q
$ hg commit -m "#5 (bar #1)"
$ cd ../tt
(1) deactivating by --rev REV
$ hg bookmark -f active-before-pull
$ hg bookmarks
* active-before-pull 3:483b76ad4309
$ hg pull -u -r b5e4babfaaa7
pulling from $TESTTMP/t
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 1 changes to 1 files
new changesets f815b3da6163:b5e4babfaaa7
1 local changesets published
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(leaving bookmark active-before-pull)
$ hg parents -q
5:b5e4babfaaa7
$ hg bookmarks
active-before-pull 3:483b76ad4309
(discard pulled changes)
$ hg update -q 483b76ad4309
$ hg rollback -q
(2) deactivating by --branch BRANCH
$ hg bookmark -f active-before-pull
$ hg bookmarks
* active-before-pull 3:483b76ad4309
$ hg pull -u -b bar
pulling from $TESTTMP/t
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 1 changes to 1 files
new changesets f815b3da6163:b5e4babfaaa7
1 local changesets published
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(leaving bookmark active-before-pull)
$ hg parents -q
5:b5e4babfaaa7
$ hg bookmarks
active-before-pull 3:483b76ad4309
(discard pulled changes)
$ hg update -q 483b76ad4309
$ hg rollback -q
(3) deactivating by URL#ANOTHER-BRANCH
$ hg bookmark -f active-before-pull
$ hg bookmarks
* active-before-pull 3:483b76ad4309
$ hg pull -u $TESTTMP/t#bar
pulling from $TESTTMP/t
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 1 changes to 1 files
new changesets f815b3da6163:b5e4babfaaa7
1 local changesets published
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
(leaving bookmark active-before-pull)
$ hg parents -q
5:b5e4babfaaa7
$ hg bookmarks
active-before-pull 3:483b76ad4309
$ cd ..
Issue622: hg init && hg pull -u URL doesn't checkout default branch
$ hg init test
$ cd test
$ echo foo>foo
$ hg addremove
adding foo
$ hg commit -m 1
$ cd ..
$ hg init empty
$ cd empty
$ hg pull -u ../test
pulling from ../test
requesting all changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
new changesets 340e38bdcde4
1 files updated, 0 files merged, 0 files removed, 0 files unresolved