Changelog for #2147

Release handler and undefined releasePoint instance

changelog.txt

@@ -13,7 +13,7 @@ OPENSEADRAGON CHANGELOG
 * Fixed: Setting useCanvas to false would break the viewer (#2116 @rvv-bouvet)
 * Allow silencing multi-image warnings on viewport coordinate conversion functions (#2120 @claycoleman)
 * Fixed: Swiping fast multiple times made contact points in MouseTracker out of sync for touch events (#2121 @ronnymikalsen)
-* Made MouseTracker more robust in certain scenarios (#2134 @Aiosa)
+* Made MouseTracker more robust in certain scenarios (#2134, #2147 @Aiosa)
 * Exposed TiledImage's private functions for better maintainability (#2134 @Aiosa)
 * Fixed an issue where full page mode wouldn't grow properly if you resized the window (#2100 @TanukiSharp)
 * Tile cache keys are now generated by the tile source, so it's easier to override them as needed (#2138 @Aiosa)

src/mousetracker.js

@@ -3561,7 +3561,7 @@
                 eventInfo.shouldReleaseCapture = false;
 
                 // Release (pressed in another element)
-                if ( tracker.releaseHandler ) {
+                if ( tracker.releaseHandler && releasePoint ) {
                     tracker.releaseHandler(
                         {
                             eventSource:           tracker,