prev: jump to parent's successor if parent is obsolete and topic is involved
`hg stack` shows a linear chain of commits even when they are not linear chain
and some changesets are obsoleted and have successors as separate head. This is
very nice to have a post evolution view of the stack. However when `hg prev` is
run on an unstable changeset whose parent is obsolete and does not topic but
parents successor has the topic, it shows no parent on the topic.
This patch makes `hg prev` update to parent's successor and make things follow
the stack order.
#require test-repo
Enable obsolescence to avoid the warning issue when obsmarker are found
$ cat << EOF >> $HGRCPATH
> [diff]
> git = yes
> [experimental]
> evolution=all
> EOF
Go back in the hg repo
$ cd $TESTDIR/..
$ for node in `hg log --rev 'not public() and ::. and not desc("# no-check-commit")' --template '{node|short}\n'`; do
> hg export $node | ${RUNTESTDIR}/../contrib/check-commit > ${TESTTMP}/check-commit.out
> if [ $? -ne 0 ]; then
> echo "Revision $node does not comply with rules"
> echo '------------------------------------------------------'
> cat ${TESTTMP}/check-commit.out
> echo
> fi
> done