Improved error message for extensions overriding commands (with test): - Old text "module foo overrides bar" was misread as overriding module bar. - Only print a single warning line per extension instead of one for each command.

#!/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