8237372: NullPointerException in TabPaneSkin.stopDrag

Test simulates a single mouse-released event. Fix simply guards against the null case.
openjdk · Jan 17, 2020 · 923a63b · 923a63b
1 parent 16cea41
commit 923a63b
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Showing 2 changed files with 29 additions and 8 deletions.
diff --git a/modules/javafx.controls/src/main/java/javafx/scene/control/skin/TabPaneSkin.java b/modules/javafx.controls/src/main/java/javafx/scene/control/skin/TabPaneSkin.java
@@ -2213,14 +2213,16 @@ private void stopDrag() {
             return;
         }
         // Animate tab header being dragged to its final position.
-        dragHeaderSourceX = dragTabHeader.getLayoutX();
-        dragHeaderTransitionX = dragHeaderDestX - dragHeaderSourceX;
-        dragHeaderAnim.playFromStart();
-
-        // Reorder the tab list.
-        if (dragHeaderStartX != dragHeaderDestX) {
-            ((TabObservableList<Tab>) getSkinnable().getTabs()).reorder(dragTabHeader.tab, swapTab);
-            swapTab = null;
+        if (dragTabHeader != null) {
+            dragHeaderSourceX = dragTabHeader.getLayoutX();
+            dragHeaderTransitionX = dragHeaderDestX - dragHeaderSourceX;
+            dragHeaderAnim.playFromStart();
+
+            // Reorder the tab list.
+            if (dragHeaderStartX != dragHeaderDestX) {
+                ((TabObservableList<Tab>) getSkinnable().getTabs()).reorder(dragTabHeader.tab, swapTab);
+                swapTab = null;
+            }
         }
     }
 

diff --git a/modules/javafx.controls/src/test/java/test/javafx/scene/control/TabPaneTest.java b/modules/javafx.controls/src/test/java/test/javafx/scene/control/TabPaneTest.java
@@ -54,6 +54,7 @@
 import javafx.scene.Group;
 import javafx.scene.Scene;
 import javafx.scene.input.KeyEvent;
+import javafx.scene.input.MouseButton;
 import javafx.scene.input.MouseEvent;
 import javafx.scene.layout.StackPane;
 import javafx.scene.layout.VBox;
@@ -463,6 +464,24 @@ private void show() {
         assertSame(TabPane.TabDragPolicy.FIXED, tabPane.getTabDragPolicy());
     }
 
+    @Test public void tabDragPolicyReorderAndAsymmetricMouseEvent() {
+        tabPane.setTabDragPolicy(TabPane.TabDragPolicy.REORDER);
+        tabPane.getTabs().add(tab1);
+        tabPane.getTabs().add(tab2);
+        root.getChildren().add(tabPane);
+        show();
+
+        root.layout();
+
+        double xval = (tabPane.localToScene(tabPane.getLayoutBounds())).getMinX();
+        double yval = (tabPane.localToScene(tabPane.getLayoutBounds())).getMinY();
+
+        SceneHelper.processMouseEvent(scene,
+            MouseEventGenerator.generateMouseEvent(MouseEvent.MOUSE_RELEASED, xval+75, yval+20));
+        tk.firePulse();
+    }
+
+
     @Test public void setRotateGraphicAndSeeValueIsReflectedInModel() {
         tabPane.setRotateGraphic(true);
         assertTrue(tabPane.rotateGraphicProperty().getValue());