fix region un/combine, based on a patch by Tom Brand

2 files changed, 22 insertions, 1 deletions

diff --git a/libs/ardour/ardour/region_sorters.h b/libs/ardour/ardour/region_sorters.h
index 9fd739a4da..3afd66bf3c 100644
--- a/libs/ardour/ardour/region_sorters.h
+++ b/libs/ardour/ardour/region_sorters.h
@@ -36,6 +36,19 @@ struct LIBARDOUR_API RegionSortByLayer {
 	}
 };
 
+/* sort by RegionSortByLayerAndPosition()
+ * is equivalent to
+ * stable_sort by RegionSortByPosition();
+ * stable_sort by RegionSortByLayer();
+ */
+struct LIBARDOUR_API RegionSortByLayerAndPosition {
+	bool operator() (boost::shared_ptr<Region> a, boost::shared_ptr<Region> b) {
+		return
+			   (a->layer() < b->layer()  && a->position() < b->position())
+			|| (a->layer() == b->layer() && a->position() < b->position());
+	}
+};
+
 } // namespace
 
 #endif /* __libardour_region_sorters_h__ */
diff --git a/libs/ardour/playlist.cc b/libs/ardour/playlist.cc
index 47462a3575..d0720b985d 100644
--- a/libs/ardour/playlist.cc
+++ b/libs/ardour/playlist.cc
@@ -2809,7 +2809,14 @@ Playlist::combine (const RegionList& r)
 
 	pl->in_partition = true;
 
-	for (RegionList::const_iterator i = r.begin(); i != r.end(); ++i) {
+	/* sort by position then layer.
+	 * route_time_axis passes 'selected_regions' - which is not sorted.
+	 * here we need the top-most first, then every layer's region softed by position.
+	 */
+	RegionList sorted(r);
+	sorted.sort(RegionSortByLayerAndPosition());
+
+	for (RegionList::const_iterator i = sorted.begin(); i != sorted.end(); ++i) {
 
 		/* copy the region */
 
@@ -3050,6 +3057,7 @@ Playlist::uncombine (boost::shared_ptr<Region> target)
 
 	for (vector<boost::shared_ptr<Region> >::iterator i = originals.begin(); i != originals.end(); ++i) {
 		add_region ((*i), (*i)->position());
+		set_layer((*i), (*i)->layer());
 	}
 
 	in_partition = false;