evolve: move a code block to have right value in has_some_val
Because of this we were having wrong value of has_some_val and
had some buggy behavior which is being fixed by this patch.
Fixed behavior is reflected by the changes in test file.
topic: add tests which demonstrate topicset failure of FilteredRepoLookupError
When topics are used, it fails to find hidden revs mentioned in a revset as
we are not using unfiltered view of repo. Next patch will fix it.