Fix: Uncaught errors in drawingModeController.handleSelection() (#87)

src/controllers/DrawingModeController.js

@@ -324,7 +324,7 @@ class DrawingModeController extends AnnotationModeController {
         }
 
         const location = this.annotator.getLocationFromEvent(event, TYPES.point);
-        if (!location) {
+        if (!location || Object.keys(this.threads).length === 0) {
             return;
         }
 

src/controllers/__tests__/DrawingModeController-test.js

@@ -410,6 +410,18 @@ describe('controllers/DrawingModeController', () => {
             expect(stubs.clean).to.not.be.called;
         });
 
+        it('should do nothing if no drawing threads exist', () => {
+            stubs.clean = sandbox.stub(controller, 'removeSelection');
+            stubs.getLoc.returns({
+                x: 15,
+                y: 15,
+                page: 1
+            });
+            controller.threads = {};
+            controller.handleSelection('event');
+            expect(stubs.clean).to.not.be.called;
+        });
+
         it('should call select on an thread found in the data store', () => {
             stubs.select = sandbox.stub(controller, 'select');
             stubs.clean = sandbox.stub(controller, 'removeSelection');