if [ "$PS1" ]; then

        upstream_hg_completion="~/.bash.d/S200_hg_completion.sh"
        if [ -e $upstream_hg_completion ] ; then
                . $upstream_hg_completion
        else
        
                _hg_commands()
                {
                    local commands="$(hg -v help | sed -e '1,/^list of commands:/d' \
                                                       -e '/^global options:/Q' \
                				       -e '/^ [^ ]/!d; s/[,:]//g;')"
                    
                    # hide debug commands from users, but complete them if 
                    # specifically asked for
                    if [[ "$cur" == de* ]]; then
                	commands="$commands debugcheckstate debugstate debugindex"
                	commands="$commands debugindexdot debugwalk"
                    fi
                    COMPREPLY=( ${COMPREPLY[@]:-} $(compgen -W "$commands" -- "$cur") )
                }
                
                _hg_paths()
                {
                    local paths="$(hg paths | sed -e 's/ = .*$//')"
                    COMPREPLY=(${COMPREPLY[@]:-} $( compgen -W "$paths" -- "$cur" ))
                }
                
                _hg_tags()
                {
                    local tags="$(hg tags | sed -e 's/[0-9]*:[a-f0-9]\{40\}$//; s/ *$//')"
                    COMPREPLY=( ${COMPREPLY[@]:-} $(compgen -W "$tags" -- "$cur") )
                }
                
                # this is "kind of" ugly...
                _hg_count_non_option()
                {
                    local i count=0
                    local filters="$1"
                
                    for (( i=1; $i<=$COMP_CWORD; i++ )); do
                	if [[ "${COMP_WORDS[i]}" != -* ]]; then
                	    for f in $filters; do
                		if [[ ${COMP_WORDS[i-1]} == $f ]]; then
                		    continue 2
                		fi
                	    done
                	    count=$(($count + 1))
                	fi
                    done
                
                    echo $(($count - 1))
                }
                
                _hg()
                {
                    local cur prev cmd opts i
                
                    COMPREPLY=()
                    cur="$2"
                    prev="$3"
                
                    # searching for the command 
                    # (first non-option argument that doesn't follow -R/--repository)
                    for (( i=1; $i<=$COMP_CWORD; i++ )); do
                	if [[ ${COMP_WORDS[i]} != -* ]] \
                	   && [ "${COMP_WORDS[i-1]}" != -R ] \
                	   && [ "${COMP_WORDS[i-1]}" != --repository ]; then
                	    cmd="${COMP_WORDS[i]}"
                	    break
                	fi
                    done
                
                    if [[ "$cur" == -* ]]; then
                	opts="$(hg -v help | sed -e '1,/^global options/d; /^ -/!d')"
                
                	if [ -n "$cmd" ]; then
                	    opts="$opts $(hg help "$cmd" | sed -e '/^ -/!d; s/ [^-][^ ]*//')"
                	fi
                
                	COMPREPLY=( ${COMPREPLY[@]:-} $(compgen -W "$opts" -- "$cur") )
                	return
                    fi
                
                    if [ "$prev" = -R ] || [ "$prev" = --repository ]; then
                        COMPREPLY=(${COMPREPLY[@]:-} $( compgen -d -- "$cur" ))
                	return
                    fi
                
                    if [ -z "$cmd" ] || [ $COMP_CWORD -eq $i ]; then
                	_hg_commands
                	return
                    fi
                
                    if [ "$cmd" != status ] && [ "$prev" = -r ] || [ "$prev" = --rev ]; then
                	_hg_tags
                	return
                    fi
                
                    case "$cmd" in
                	help)
                	    _hg_commands
                	;;
                	export|manifest|update|checkout|up|co)
                	    _hg_tags
                	;;
                	pull|push|outgoing|incoming)
                	    _hg_paths
                	    COMPREPLY=(${COMPREPLY[@]:-} $( compgen -d -- "$cur" ))
                	;;
                	paths)
                	    _hg_paths
                	;;
                	clone)
                	    local count=$(_hg_count_non_option)
                	    if [ $count = 1 ]; then
                		_hg_paths
                	    fi
                	    COMPREPLY=(${COMPREPLY[@]:-} $( compgen -d -- "$cur" ))
                	;;
                	cat)
                	    local count=$(_hg_count_non_option -o --output)
                	    if [ $count = 2 ]; then
                		_hg_tags
                	    else
                		COMPREPLY=(${COMPREPLY[@]:-} $( compgen -f -- "$cur" ))
                	    fi
                	;;
                	*) 
                            COMPREPLY=(${COMPREPLY[@]:-} $( compgen -f -- "$cur" ))
                	;;
                    esac
                
                }
                
                complete -o filenames -F _hg hg
        
        fi

fi