Uses hg convert to truncate a repository from an initial revision. If no revision is specified, the whole repository is converted. It optionally uses an intermediate repository (cache) in case the source repository can be written during the convert operation.

hg-truncate-and-sync.sh

#!/bin/bash
#
# Uses hg convert to strip a repository from <start revision>
# If no revision is specified, the whole repository is converted.
# Optionally a "cache" repository can be used, to be sure that the
# source repository is not written during the convert operation.
#

while getopts "r:s:d:c:h?" opt; do
	case $opt in
		r)
			REVISION=$OPTARG
		;;
		s)
			SOURCE=$OPTARG
		;;
		d)
			DESTINATION=$OPTARG
		;;
		c)
			CACHE=$OPTARG
		;;
		*)
			echo "Usage: $0 -s <source> -d <destination> [-r <start revision>] [-c <cache>]"
			exit 1
		;;
	esac
done

if test -z "$SOURCE" -o -z "$DESTINATION"; then
	echo "You must specify source and destination"
	exit 1
fi

if [ ! -d "$SOURCE/.hg" ]; then
	echo "$SOURCE is not a mercurial repository"
	exit 1
fi

if [ -n "$REVISION" ]; then
	HG_CONFIG="--config convert.hg.startrev=$REVISION"
fi

if [ -n "$CACHE" ]; then
	if [ -d "$CACHE/.hg" ]; then
		hg -R $CACHE pull $SOURCE
	else
		hg clone -U $SOURCE $CACHE
	fi
	REAL_SOURCE=$CACHE
else
	REAL_SOURCE=$SOURCE
fi

hg $HG_CONFIG convert $REAL_SOURCE $DESTINATION