Issue a warning if "-r ." is used with two working directory parents. Rationale for not aborting instead: The first parent is usually more important as it is the local branch during a merge and commands like 'hg diff' and 'hg diff -r.' behave still identically (except for the warning of course). Added a test for log -r. with one and two parents.

#!/bin/sh

mkdir a
cd a
hg init
echo a > a
hg add a
hg commit -m test -d '0 0'

# Default operation
hg clone . ../b
cd ../b
cat a
hg verify

# No update
hg clone -U . ../c
cd ../c
cat a 2>/dev/null || echo "a not present"
hg verify

# Default destination
mkdir ../d
cd ../d
hg clone ../a
cd a
hg cat a