convert: clear the dirstate before a conversion, invalidate it afterwards
Clearing it before the conversion protects us from whatever data were
there (file copies in particular).
Invalidating it after the conversion avoids writing a possibly
inconsistent dirstate to disk.
#!/bin/sh
mkdir t
cd t
hg init
echo "invalid" > .hg/hgrc
hg status 2>&1 |sed -e "s:/.*\(/t/.*\):...\1:"