interfaces: introduce and use a protocol class for the `mpatch` module
See
f2832de2a46c for details when this was done for the `bdiff` module.
Two things worth pointing out-
1) The `cffi` module "inherits" the `pure` implementation of `patchedsize()`
because of its wildcard import.
2) It's odd that the `mpatchError` lives in both `pure` and `cext` modules.
I initially thought to move the exception into the new class, and make the
existing class name an alias to the class in the new location, but the exception
is created in C code by the `cext` module, so that won't work. I don't think a
protocol class is approriate, because there's nothing special about the class to
distinguish from any other `Exception`. Fortunately, nobody is catching this
exception in core, so we can kick the can down the road.
$ hg init repo
$ cd repo
$ echo line 1 > foo
$ hg ci -qAm 'add foo'
copy foo to bar and change both files
$ hg cp foo bar
$ echo line 2-1 >> foo
$ echo line 2-2 >> bar
$ hg ci -m 'cp foo bar; change both'
in another branch, change foo in a way that doesn't conflict with
the other changes
$ hg up -qC 0
$ echo line 0 > foo
$ hg cat foo >> foo
$ hg ci -m 'change foo'
created new head
we get conflicts that shouldn't be there
$ hg merge -P
changeset: 1:484bf6903104
user: test
date: Thu Jan 01 00:00:00 1970 +0000
summary: cp foo bar; change both
$ hg merge --debug
unmatched files in other:
bar
all copies found (* = to merge, ! = divergent, % = renamed and deleted):
on remote side:
src: 'foo' -> dst: 'bar' *
checking for directory renames
resolving manifests
branchmerge: True, force: False, partial: False
ancestor: e6dc8efe11cc, local: 6a0df1dad128+, remote: 484bf6903104
starting 4 threads for background file closing (?)
preserving foo for resolve of bar
preserving foo for resolve of foo
bar: remote copied from foo -> m
picked tool ':merge' for bar (binary False symlink False changedelete False)
merging foo and bar to bar
my bar@6a0df1dad128+ other bar@484bf6903104 ancestor foo@e6dc8efe11cc
premerge successful
foo: versions differ -> m
picked tool ':merge' for foo (binary False symlink False changedelete False)
merging foo
my foo@6a0df1dad128+ other foo@484bf6903104 ancestor foo@e6dc8efe11cc
premerge successful
0 files updated, 2 files merged, 0 files removed, 0 files unresolved
(branch merge, don't forget to commit)
contents of foo
$ cat foo
line 0
line 1
line 2-1
contents of bar
$ cat bar
line 0
line 1
line 2-2
$ cd ..