bash_completion: don't complete export with "garbage" when mq is not around
The "garbage" is the output of hg help printed when a command is not found.
#!/bin/sh
echo "[extensions]" >> $HGRCPATH
echo "mq=" >> $HGRCPATH
hg init a
cd a
echo 'base' > base
hg ci -Ambase -d '1 0'
hg qnew a
hg qnew b
hg qnew c
hg qdel c
hg qpop
hg qdel c
hg qseries
ls .hg/patches
hg qpop
hg qdel -k b
ls .hg/patches
hg qdel -r a
hg qapplied
hg log --template '{rev} {desc}\n'
hg qnew d
hg qnew e
hg qnew f
hg qdel -r e
hg qdel -r qbase:e
hg qapplied
hg log --template '{rev} {desc}\n'