previous: fix behavior on obsolete cset when topic is involved (issue5708)
This patch fixes the behavior of `hg previous` when done on an obsolete
changeset having a successor of different topic.
The underlying code is bit messed up, I wanted to split the topic handling to
topic extension but I have postponed it to next bug.
syntax: re
/figures/[^/]+\.png$
^html/
\.pyc$
~$
\.swp$
\.orig$
\.rej$
^tests/.*\.err$
^tests/easy_run.sh$
^build/
^dist/
^MANIFEST$
^docs/tutorials/.*\.rst$
\.ico$
tests/\.testtimes
^docs/training/graphs/
^docs/training/html/
^docs/training/index.html
^docs/training/graphviz-images/
^docs/training/img/
^docs/training/output/
^docs/training/pandocfilters/