tests/test-diffdir

mq: don't allow patches with some reserved names

The current list of reserved names includes only mq control files.

Also, reserve names starting with ".hg" (to avoid troubles with
e.g. .hgignore and .hgtags), and with ".mq" (to allow future
extensions).

This should fix issue841.

#!/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