diff --git a/libs/ardour/location.cc b/libs/ardour/location.cc
index 6ce1b5f282..55cf2256d9 100644
--- a/libs/ardour/location.cc
+++ b/libs/ardour/location.cc
@@ -282,6 +282,7 @@ Location::set_end (framepos_t e, bool force, bool allow_bbt_recompute)
 		if (allow_bbt_recompute) {
 			recompute_bbt_from_frames ();
 		}
+
 		end_changed(this); /* EMIT SIGNAL */
 		EndChanged(); /* EMIT SIGNAL */
 
@@ -296,22 +297,92 @@ Location::set_end (framepos_t e, bool force, bool allow_bbt_recompute)
 }
 
 int
-Location::set (framepos_t start, framepos_t end, bool allow_bbt_recompute)
+Location::set (framepos_t s, framepos_t e, bool allow_bbt_recompute)
 {
-	if (start < 0 || end < 0) {
+	if (s < 0 || e < 0) {
 		return -1;
 	}
 
 	/* check validity */
-	if (((is_auto_punch() || is_auto_loop()) && start >= end) || (!is_mark() && start > end)) {
+	if (((is_auto_punch() || is_auto_loop()) && s >= e) || (!is_mark() && s > e)) {
 		return -1;
 	}
 
-	/* now we know these values are ok, so force-set them */
-	int const s = set_start (start, true, allow_bbt_recompute);
-	int const e = set_end (end, true, allow_bbt_recompute);
+        bool start_change = false;
+        bool end_change = false;
 
-	return (s == 0 && e == 0) ? 0 : -1;
+	if (is_mark()) {
+
+		if (_start != s) {
+			_start = s;
+			_end = s;
+
+			if (allow_bbt_recompute) {
+				recompute_bbt_from_frames ();
+			}
+
+                        start_change = true;
+                        end_change = true;
+		}
+
+		assert (_start >= 0);
+		assert (_end >= 0);
+
+	} else {
+                
+                if (s != _start) {
+
+                        framepos_t const old = _start;
+                        _start = s;
+
+                        if (allow_bbt_recompute) {
+                                recompute_bbt_from_frames ();
+                        }
+
+                        start_change = true;
+                        
+                        if (is_session_range ()) {
+                                Session::StartTimeChanged (old); /* EMIT SIGNAL */
+                                AudioFileSource::set_header_position_offset (s);
+                        }
+                }
+                        
+                 
+                if (e != _end) {
+                        
+                        framepos_t const old = _end;
+                        _end = e;
+
+                        if (allow_bbt_recompute) {
+                                recompute_bbt_from_frames ();
+                        }
+                        
+                        end_change = true;
+
+                        if (is_session_range()) {
+                                Session::EndTimeChanged (old); /* EMIT SIGNAL */
+                        }
+                }
+
+                assert (_end >= 0);
+        }
+
+        if (start_change) {
+                start_changed(this); /* EMIT SIGNAL */
+                StartChanged(); /* EMIT SIGNAL */
+        }
+
+        if (end_change) {
+                end_changed(this); /* EMIT SIGNAL */
+                EndChanged(); /* EMIT SIGNAL */
+        }
+
+        if (start_change && end_change) {
+                changed (this);
+                Changed ();
+        }
+
+        return 0;
 }
 
 int