test-exchange-case-D1: avoid stripping obsolescence marker
The test needs to have changeset unknown locally with obsolescence markers still
applying to them. So we make sure the markers are not stripped (future 4.3 strip
markers by default).
#require test-repo pyflakes
Copied from Mercurial core (60ee2593a270)
$ cd "`dirname "$TESTDIR"`"
run pyflakes on all tracked files ending in .py or without a file ending
(skipping binary file random-seed)
$ hg locate 'set:(**.py or grep("^#!.*python")) - removed()' 2>/dev/null \
> | xargs pyflakes 2>/dev/null