Fix up gain envelope handling with region split. Fixes #3306.

git-svn-id: svn://localhost/ardour2/branches/3.0@7510 d708f5d6-7413-0410-9779-e7cbd77b26cf

3 files changed, 15 insertions, 10 deletions

diff --git a/libs/ardour/audioregion.cc b/libs/ardour/audioregion.cc
index 8c66591fa7..f0219ce729 100644
--- a/libs/ardour/audioregion.cc
+++ b/libs/ardour/audioregion.cc
@@ -160,8 +160,10 @@ AudioRegion::AudioRegion (boost::shared_ptr<const AudioRegion> other, nframes64_
 	, _automatable (other->session())
 	, _fade_in (new AutomationList (*other->_fade_in))
 	, _fade_out (new AutomationList (*other->_fade_out))
-	  /* XXX is this guaranteed to work for all values of offset+offset_relative? */
-	, _envelope (new AutomationList (*other->_envelope, _start, _start + _length))
+	  /* As far as I can see, the _envelope's times are relative to region position, and have nothing
+	     to do with sources (and hence _start).  So when we copy the envelope, we just use the supplied offset.
+	  */
+	, _envelope (new AutomationList (*other->_envelope, offset, other->_length))
 	, _fade_in_suspended (0)
 	, _fade_out_suspended (0)
 {
diff --git a/libs/ardour/playlist.cc b/libs/ardour/playlist.cc
index e55b82c06b..8ea84b96bf 100644
--- a/libs/ardour/playlist.cc
+++ b/libs/ardour/playlist.cc
@@ -1401,12 +1401,15 @@ Playlist::_split_region (boost::shared_ptr<Region> region, framepos_t playlist_p
 	{
 		PropertyList plist;
 		
-		plist.add (Properties::start, region->start());
 		plist.add (Properties::length, before);
 		plist.add (Properties::name, before_name);
 		plist.add (Properties::left_of_split, true);
-		
-		left = RegionFactory::create (region, plist);
+
+		/* note: we must use the version of ::create with an offset here,
+		   since it supplies that offset to the Region constructor, which
+		   is necessary to get audio region gain envelopes right.
+		*/
+		left = RegionFactory::create (region, 0, plist);
 	}
 
 	RegionFactory::region_name (after_name, region->name(), false);
@@ -1414,12 +1417,12 @@ Playlist::_split_region (boost::shared_ptr<Region> region, framepos_t playlist_p
 	{
 		PropertyList plist;
 		
-		plist.add (Properties::start, region->start() + before);
 		plist.add (Properties::length, after);
 		plist.add (Properties::name, after_name);
 		plist.add (Properties::right_of_split, true);
 
-		right = RegionFactory::create (region, plist);
+		/* same note as above */
+		right = RegionFactory::create (region, before, plist);
 	}
 
 	add_region_internal (left, region->position());
diff --git a/libs/ardour/region.cc b/libs/ardour/region.cc
index 6dc090ce3c..234dddcc45 100644
--- a/libs/ardour/region.cc
+++ b/libs/ardour/region.cc
@@ -247,10 +247,10 @@ Region::Region (const SourceList& srcs)
 
 /** Create a new Region from part of an existing one, starting at one of two places:
 
-    if @param offset_relative is true, then the start within @param other is given by @param offset
-    (i.e. relative to the start of @param other's sources, the start is @param offset + @param other.start()
+    if \a offset_relative is true, then the start within \a other is given by \a offset
+    (i.e. relative to the start of \a other's sources, the start is \a offset + \a other.start()
 
-    if @param offset_relative is false, then the start within the source is given @param offset.
+    if @param offset_relative is false, then the start within the source is given \a offset.
 */
 Region::Region (boost::shared_ptr<const Region> other, frameoffset_t offset, bool offset_relative)
 	: SessionObject(other->session(), other->name())