src/java.desktop/macosx/native/libawt_lwawt/awt/AWTWindow.m

*** 707,719 ****
--- 707,722 ----
  
              // Check if the click happened in the non-client area (title bar)
              if (p.y >= (frame.origin.y + contentRect.size.height)) {
                  JNIEnv *env = [ThreadUtilities getJNIEnvUncached];
                  jobject platformWindow = [self.javaPlatformWindow jObjectWithEnv:env];
+                 if (platformWindow != NULL) {
                      // Currently, no need to deliver the whole NSEvent.
                      static JNF_MEMBER_CACHE(jm_deliverNCMouseDown, jc_CPlatformWindow, "deliverNCMouseDown", "()V");
                      JNFCallVoidMethod(env, platformWindow, jm_deliverNCMouseDown);
+                     (*env)->DeleteLocalRef(env, platformWindow);
+                 }
              }
          }
  }
  
  - (void)constrainSize:(NSSize*)size {