Stop send mouse clicks while dragging in view only

kasmweb/core/rfb.js

@@ -903,6 +903,8 @@ export default class RFB extends EventTargetMixin {
                     return;
                 }
 
+                if (this._viewOnly) { return; }
+
                 // Otherwise we treat this as a mouse click event.
                 // Send the button down event here, as the button up
                 // event is sent at the end of this function.

kasmweb/tests/test.rfb.js

@@ -514,6 +514,13 @@ describe('Remote Frame Buffer Protocol Client', function () {
                 expect(RFB.messages.pointerEvent).to.have.been.calledTwice;
             });
 
+            it('should not send button messages when in view only', function () {
+                client._viewOnly = true;
+                client._handleMouseButton(13, 9, 0x001);
+                client._handleMouseButton(13, 9, 0x000);
+                expect(RFB.messages.pointerEvent).to.not.have.been.called;
+            });
+
             it('should send button message directly when drag is disabled', function () {
                 client.dragViewport = false;
                 client._handleMouseButton(13, 9, 0x001);