standardize ssh completion scheme:

- complete after previous unstacked short options
- complete potential options after dash
- complete on known host if neither apply

contrib/ssh

@@ -17,18 +17,29 @@ _ssh()
 	case "$prev" in
 	-F)
 		_filedir
+		return 0
 		;;
-	-*c)
+	-c)
 	    COMPREPLY=( $( compgen -W 'blowfish 3des 3des-cbc blowfish-cbc \
 			   arcfour cast128-cbc' -- $cur ) )
+	    return 0
 	    ;;
-	-*i)
+	-i)
 	    _filedir
+	    return 0
 	    ;;
-	-*l)
+	-l)
 	    COMPREPLY=( $( compgen -u -- $cur ) )
+	    return 0
 	    ;;
-	*)
+	esac
+
+	if [[ "$cur" == -* ]]; then
+		COMPREPLY=( $( compgen -W '-1 -2 -4 -6 -A -a -C -f -g -K -k -M \
+			-N -n -q -s -T -t -V -v -X -v -Y -y -b -b -c -D -e -F \
+			-i -L -l -m -O -o -p -R -S -w' -- $cur ) )
+	else
+		if [ $COMP_CWORD -eq 1 ]; then
 			# Search COMP_WORDS for '-F configfile' argument
 			set -- "${COMP_WORDS[@]}"
 			while [ $# -gt 0 ]; do
@@ -43,12 +54,11 @@ _ssh()
 				fi
 				shift
 			done
-
 			_known_hosts -a "$optconfigfile"
-
+		else
-	    [ $COMP_CWORD -eq 1 -o -n "$optconfigfile" ] || \
 			COMPREPLY=( "${COMPREPLY[@]}" $( compgen -c -- $cur ) )
-	esac
+		fi
+	fi
 
 	return 0
 }