Index: libs/ardour/audioregion.cc
===================================================================
--- libs/ardour/audioregion.cc	(revision 9941)
+++ libs/ardour/audioregion.cc	(working copy)
@@ -541,6 +541,7 @@
 	}
 
 	/* precondition: caller has verified that we cover the desired section */
+	assert(coverage(position, position+cnt-1) != OverlapNone);
 
 	if (position < _position) {
 		internal_offset = 0;
@@ -1171,6 +1172,13 @@
 {
 	/* as above, but the shift was from the front */
 
+	// can't do this, events is protected...
+	//
+	// if (_envelope.events.empty()) {
+	// 	cerr << "AudioRegion._envelope.events.empty() is TRUE, setting envelope to default\n";
+	// 	set_default_envelope();
+	// }
+
 	_envelope.truncate_start (_length);
 
 	if (_flags & RightOfSplit) {