revset: handle re.compile() errors in grep()
Raise error.ParseError instead of allowing re.error to bubble up.
#!/bin/sh
"$TESTDIR/hghave" symlink || exit 80
rm -rf a
hg init a
cd a
ln -s foo link
hg add link
hg ci -mbad link
hg rm link
hg ci -mok
hg diff -g -r 0:1 > bad.patch
hg up 0
hg import --no-commit bad.patch
hg st