simplemerge: take arguments as annotated context objects
The labels we put in conflict markers are formatted so the part before
the ':' (typically says things like "local") is padded so the ':' is
aligned among the labels. That means that if you specify a long label
for "base" but the conflict marker style is "merge" (i.e. 2-way), the
other two will have unwanted padding. We often don't specify a label
for the base, so we don't notice the problem (and it may very well be
that it didn't exist before my D11972).
I think the best fix is to pass the labels along with the context
objects, so the low-level code that switches on the marker style to
use (i.e. `simplemerge`) can do the formatting. This patch starts
doing that by passing a fully-formatted label to `simplemerge`. A
coming patch will move the formatting to `simplemerge`.
Differential Revision: https://phab.mercurial-scm.org/D12013
Test for changeset ba7c74081861
(update dirstate correctly for non-branchmerge updates)
$ hg init a
$ cd a
$ echo a > a
$ hg add a
$ hg commit -m a
$ cd ..
$ hg clone a b
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ cd a
$ hg mv a b
$ hg commit -m move
$ echo b >> b
$ hg commit -m b
$ cd ../b
$ hg pull ../a
pulling from ../a
searching for changes
adding changesets
adding manifests
adding file changes
added 2 changesets with 2 changes to 1 files
new changesets e3c9b40284e1:772b37f1ca37
(run 'hg update' to get a working copy)
$ hg update
1 files updated, 0 files merged, 1 files removed, 0 files unresolved
$ cd ..