Add chown --from and --reference value completions.

CHANGES

@@ -35,6 +35,7 @@ bash-completion (1.x)
   * Add _split_longopt() helper for improved handling of long options that
     take arguments in both "--foo bar" and "--foo=bar" formats.
   * Use _split_longopt to improve and clean up aspell, chgrp, chown completion.
+  * Add chown --from and --reference value completions.
 
   [ Todd Zullinger ]
   * Make yum complete on filenames after install, deplist, update and upgrade

bash_completion

@@ -797,6 +797,17 @@ _chown()
 
 	_split_longopt && split=true
 
+	case "$prev" in
+		--from)
+			_usergroup
+			return 0
+			;;
+		--reference)
+			_filedir
+			return 0
+			;;
+	esac
+
 	$split && return 0
 
 	# options completion