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.
adding a
assuming destination a-hg
initializing destination a-hg repository
scanning source...
sorting...
converting...
4 a
3 b
2 c
1 d
0 e
pulling from ../a
searching for changes
no changes found