convert: avoid interpreting Windows path as CVS connection strings. CVS connection strings regexp detect colons to separate protocols from path and login. Unfortunately, Windows paths contains colons and were interpreted as rsh connection strings.

#!/bin/sh

hg init
touch a
hg add a
hg ci -m "a" -d "1000000 0"

echo 123 > b
hg add b
hg diff --nodates

hg diff --nodates -r tip

echo foo > a
hg diff --nodates

hg diff -r ""
hg diff -r tip -r ""

true