Second round of Lua script API updates

share/scripts/bounce_replace.lua

@@ -24,7 +24,6 @@ function factory (params) return function ()
 
 	-- prepare undo operation
 	Session:begin_reversible_command ("Bounce+Replace Regions")
-	local add_undo = false -- keep track if something has changed
 
 	-- Iterate over Regions part of the selection
 	-- http://manual.ardour.org/lua-scripting/class_reference/#ArdourUI:RegionSelection
@@ -48,17 +47,12 @@ function factory (params) return function ()
 
 		-- create a diff of the performed work, add it to the session's undo stack
 		-- and check if it is not empty
-		if not Session:add_stateful_diff_command (playlist:to_statefuldestructible ()):empty () then
-			add_undo = true
-		end
+		Session:add_stateful_diff_command (playlist:to_statefuldestructible ())
 	end
 
 	-- all done, commit the combined Undo Operation
-	if add_undo then
-		-- the 'nil' Command here mean to use the collected diffs added above
+	if not Session:abort_empty_reversible_command () then
 		Session:commit_reversible_command (nil)
-	else
-		Session:abort_reversible_command ()
 	end
 
 end end