tests: avoid test-hup hanging on AIX
test-hup hangs on AIX. Under ksh89 on AIX (the default shell),
echo Hello; while [ ! -s not-there ]; do true; done
produces no output while the loop executes. Replacing 'true' with 'sleep 0'
fixes, as does using a less broken shell. ksh93 is fine.
Update check-code.py to look for this, and make same change in test-serve.t.
In fact test-serve works fine, probably because of additional commands between
echo and the loop, but that's a subtlety not easy to test for.
$ "$TESTDIR/hghave" unix-permissions || exit 80
$ hg init a
$ echo a > a/a
$ hg -R a ci -A -m a
adding a
$ hg clone a b
updating to branch default
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ echo b > b/b
$ hg -R b ci -A -m b
adding b
$ chmod 100 a/.hg/store
$ hg -R b push a
pushing to a
abort: could not lock repository a: Permission denied
[255]
$ chmod 700 a/.hg/store