fix traceback of extdiff after a merge
- files that comes from a different branch are marked as modified
but aren't present in the original manifest
- add a testcase for extdiff and for regular diff
adding a
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
adding b
1:97d72e5f12c7
% should pull one change
pulling from ../a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
1:97d72e5f12c7
adding c
pulling from ../a
searching for changes
adding changesets
adding manifests
adding file changes
added 1 changesets with 1 changes to 1 files (+1 heads)
merging with new head 2:97d72e5f12c7
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
new changeset 3:cd3a41621cf0 merges remote changes with local
a
b
c