reverse sense of return value from python hooks. old scheme (False/None/0/'' == fail) made coding style unnatural, did not allow use of mercurial commands as hooks. new scheme (False/None/0 == pass) is pythonic, does not require peculiar "return True" at ends of hooks, allows hooks like this: [hooks] # update working dir after push into this repo changegroup.update = python:mercurial.commands.update

#!/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