Don't write undo records for automation that moves with regions when nothing changes about the automation.

git-svn-id: svn://localhost/ardour2/branches/3.0@7665 d708f5d6-7413-0410-9779-e7cbd77b26cf

2 files changed, 21 insertions, 6 deletions

diff --git a/libs/evoral/evoral/ControlList.hpp b/libs/evoral/evoral/ControlList.hpp
index 9d3ba09ef1..f5aef8127d 100644
--- a/libs/evoral/evoral/ControlList.hpp
+++ b/libs/evoral/evoral/ControlList.hpp
@@ -123,7 +123,7 @@ public:
 	void erase_range (double start, double end);
 	void erase (iterator);
 	void erase (iterator, iterator);
-	void move_ranges (std::list< RangeMove<double> > const &);
+	bool move_ranges (std::list< RangeMove<double> > const &);
 	void modify (iterator, double, double);
 
 	boost::shared_ptr<ControlList> cut (double, double);
diff --git a/libs/evoral/src/ControlList.cpp b/libs/evoral/src/ControlList.cpp
index b49b294288..72af04a2d1 100644
--- a/libs/evoral/src/ControlList.cpp
+++ b/libs/evoral/src/ControlList.cpp
@@ -510,7 +510,9 @@ ControlList::erase_range_internal (double start, double endt, EventList & events
 		cp.when = endt;
 		e = upper_bound (events.begin(), events.end(), &cp, time_comparator);
 		events.erase (s, e);
-		erased = true;
+		if (s != e) {
+			erased = true;
+		}
 	}
 
 	return erased;
@@ -1354,8 +1356,10 @@ ControlList::paste (ControlList& alist, double pos, float /*times*/)
 	return true;
 }
 
-/** Move automation around according to a list of region movements */
-void
+/** Move automation around according to a list of region movements.
+ *  @param return true if anything was changed, otherwise false (ie nothing needed changing)
+ */
+bool
 ControlList::move_ranges (const list< RangeMove<double> >& movements)
 {
 	typedef list< RangeMove<double> > RangeMoveList;
@@ -1367,11 +1371,21 @@ ControlList::move_ranges (const list< RangeMove<double> >& movements)
 		EventList old_events = _events;
 
 		/* clear the source and destination ranges in the new list */
+		bool things_erased = false;
 		for (RangeMoveList::const_iterator i = movements.begin (); i != movements.end (); ++i) {
 
-			erase_range_internal (i->from, i->from + i->length, _events);
-			erase_range_internal (i->to, i->to + i->length, _events);
+			if (erase_range_internal (i->from, i->from + i->length, _events)) {
+				things_erased = true;
+			}
+
+			if (erase_range_internal (i->to, i->to + i->length, _events)) {
+				things_erased = true;
+			}
+		}
 
+		/* if nothing was erased, there is nothing to do */
+		if (!things_erased) {
+			return false;
 		}
 
 		/* copy the events into the new list */
@@ -1399,6 +1413,7 @@ ControlList::move_ranges (const list< RangeMove<double> >& movements)
 	}
 
 	maybe_signal_changed ();
+	return true;
 }
 
 void