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 init rep
cd rep
mkdir dir
touch foo dir/bar
hg -v addremove
hg -v commit -m "add 1" -d "1000000 0"
cd dir/
touch ../foo_2 bar_2
hg -v addremove
hg -v commit -m "add 2" -d "1000000 0"