Issue a warning if "-r ." is used with two working directory parents.
Rationale for not aborting instead:
The first parent is usually more important as it is the local branch
during a merge and commands like 'hg diff' and 'hg diff -r.' behave still
identically (except for the warning of course).
Added a test for log -r. with one and two parents.
1:016807e6fdaf
0:eb43f19ff115
016807e6fdaf tip
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
eb43f19ff115
eb43f19ff115+
reverting file1
? file1.orig
eb43f19ff115
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
? file1.orig
016807e6fdaf tip
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
? file1.orig
016807e6fdaf tip
? file1.orig
016807e6fdaf tip
? file1.orig
016807e6fdaf tip
0 files updated, 0 files merged, 0 files removed, 0 files unresolved
? file1.orig
016807e6fdaf tip