Merge remote-tracking branch 'origin/open840' into open-master

platform/features/plot/src/PlotController.js

@@ -113,8 +113,20 @@ define(
                 }
             }
 
+            // Release the current subscription (called when scope is destroyed)
+            function releaseSubscription() {
+                if (subscription) {
+                    subscription.unsubscribe();
+                    subscription = undefined;
+                }
+            }
+
+            // Subscribe to telemetry when a domain object becomes available
             $scope.$watch('domainObject', subscribe);
 
+            // Unsubscribe when the plot is destroyed
+            $scope.$on("$destroy", releaseSubscription);
+
             return {
                 /**
                  * Get the color (as a style-friendly string) to use

platform/features/plot/test/PlotControllerSpec.js

@@ -173,6 +173,19 @@ define(
                 // Placeholder; need to support requesting telemetry
                 expect(controller.isRequestPending()).toBeFalsy();
             });
+
+            it("unsubscribes when destroyed", function () {
+                // Make an object available
+                mockScope.$watch.mostRecentCall.args[1](mockDomainObject);
+                // Make sure $destroy is what's listened for
+                expect(mockScope.$on.mostRecentCall.args[0]).toEqual('$destroy');
+                // Also verify precondition
+                expect(mockSubscription.unsubscribe).not.toHaveBeenCalled();
+                // Destroy the scope
+                mockScope.$on.mostRecentCall.args[1]();
+                // Should have unsubscribed
+                expect(mockSubscription.unsubscribe).toHaveBeenCalled();
+            });
         });
     }
 );