Calling revlog.addgroup with an empty changegroup now raises RevlogError.
The empty changegroup can be caused by remote servers dying soon after
findincoming, and further code in pull assumes (correctly) that there are
new changesets.
#!/bin/sh
hg
hg -q
hg help
hg -q help
hg add -h
hg add --skjdfks
hg help diff
hg help status
hg -q help status
hg help foo
hg skjdfks
exit 0