'*' causes the resulting RE to match 0 or more repetitions of the preceding RE:
>>> bool(re.search('.*', ''))
>>> True
This causes an infinite loop because currently we're only checking if there was
a match without looking at where we are in the searched string.
Some tests ended up in a directory several directories deeper than $TESTTMP,
usually because some 'cd ..' had been forgotten between different test cases.
Add 'cd ..' where they are missing so the tests get back where they started.
Matching lines without trailing '\n' was missing the last character.
That seems to have been an unintended side effect of 8abe3f27975c.
The test in c21748e4cd4d documents the bad behaviour.
