Fix 3-way-merge of original parent, workdir and new parent.
The dirstate has to match what is in the repository (what would be
checked out with 'hg update -C'), because the resulting file may be
identical to the new parent, or it may be completely different.
Previously the dirstate wasn't updated, so if you changed the file to
look like the original parent, it might be considered unmodified
relative to the new parent.
+ hg init
+ hg add a
+ hg commit -m 1 -d 0 0
+ hg status
+ hg copy a b
+ hg status
A b
+ hg --debug commit -m 2 -d 0 0
b
b: copy a:b789fdd96dc2f3bd229c1dd8eedf0fc60e2b68e3
+ hg history
changeset: 1:3b5b84850bbe
tag: tip
user: test
date: Thu Jan 1 00:00:00 1970
summary: 2
changeset: 0:c19d34741b0a
user: test
date: Thu Jan 1 00:00:00 1970
summary: 1
+ hg log a
changeset: 0:c19d34741b0a
user: test
date: Thu Jan 1 00:00:00 1970
summary: 1
566e338d09a089ba737c21e0d3759980 .hg/data/b.d
3268d2f51b2d2d423ff01b59eb6fbb14 bsum
70909ca2ecf494c71e9184b445e040ee asum
+ hg verify
checking changesets
checking manifests
crosschecking files in changesets and manifests
checking files
2 files, 2 changesets, 2 total revisions