tests: demonstrate that rename is followed to wrong parent from merge This test case shows another way that copies are handled differently between `hg st` (pathcopies()) and `hg co -m` (mergecopies). The reason is that pathcopies() calls _tracefiles(), which checks that the file nodeid of an ancestor matches the file nodeid in the base commit. mergecopies() should probably be doing the same. Differential Revision: https://phab.mercurial-scm.org/D6323