Bug 537364 - [GTK] DateTime instances leaks in the widgetTable after

disposal

Only register/deregister handles if they are not already
registered/deregistered.

The test checks leaking widget handle in the widgetTable: after
disposal, no traces of a widget should be found there.

Change-Id: I678996b5004d348d6f1e24c9e8e5708e8c46bd9d
Signed-off-by: Andrey Loskutov <loskutov@gmx.de>

2 files changed, 36 insertions, 5 deletions

diff --git a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/DateTime.java b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/DateTime.java
index bd68e8d79a..98b1bac10a 100644
--- a/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/DateTime.java
+++ b/bundles/org.eclipse.swt/Eclipse SWT/gtk/org/eclipse/swt/widgets/DateTime.java
@@ -791,6 +791,9 @@ public int getMonth () {
 
 @Override
 String getNameText () {
+	if(calendar == null) {
+		return "";
+	}
 	if (isTime ()) {
 		return getHours () + ":" + getMinutes () + ":" + getSeconds ();
 	} else {
@@ -1846,8 +1849,8 @@ void updateControl() {
 @Override
 void register () {
 	super.register ();
-	if (containerHandle != 0) display.addWidget (containerHandle, this);
-	if (textEntryHandle != 0) display.addWidget (textEntryHandle, this);
+	if (containerHandle != 0 && containerHandle != handle) display.addWidget (containerHandle, this);
+	if (textEntryHandle != 0 && textEntryHandle != containerHandle) display.addWidget (textEntryHandle, this);
 }
 
 @Override
@@ -1858,9 +1861,8 @@ GdkRGBA defaultBackground () {
 @Override
 void deregister () {
 	super.deregister ();
-	if (containerHandle != 0) display.removeWidget (containerHandle);
-	if (fixedHandle != 0) display.removeWidget (fixedHandle);
-	if (textEntryHandle != 0) display.removeWidget (textEntryHandle);
+	if (containerHandle != 0 && containerHandle != handle) display.removeWidget (containerHandle);
+	if (textEntryHandle != 0 && textEntryHandle != containerHandle) display.removeWidget (textEntryHandle);
 }
 
 int getArrow(long /*int*/ widget) {
diff --git a/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_widgets_Widget.java b/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_widgets_Widget.java
index fc5f543679..5fbf68c8aa 100644
--- a/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_widgets_Widget.java
+++ b/tests/org.eclipse.swt.tests/JUnit Tests/org/eclipse/swt/tests/junit/Test_org_eclipse_swt_widgets_Widget.java
@@ -17,12 +17,14 @@ import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
+import java.lang.reflect.Field;
 import java.util.function.BooleanSupplier;
 
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.graphics.GC;
 import org.eclipse.swt.widgets.Control;
+import org.eclipse.swt.widgets.Display;
 import org.eclipse.swt.widgets.Event;
 import org.eclipse.swt.widgets.Listener;
 import org.eclipse.swt.widgets.Shell;
@@ -57,14 +59,22 @@ public void tearDown() {
 	if (widget != null) {
 		assertEquals(disposedIntentionally, widget.isDisposed());
 	}
+	Display display = null;
 	if (!disposedIntentionally) {
 		assertFalse(shell.isDisposed());
+		display = shell.getDisplay();
 	}
 	shell.dispose();
 	if (widget != null) {
 		assertTrue(widget.isDisposed());
+		if(display != null) {
+			assertNotExists(getWidgetTable(display), widget);
+		}
 	}
 	assertTrue(shell.isDisposed());
+	if(display != null) {
+		assertNotExists(getWidgetTable(display), shell);
+	}
 }
 @Test
 public void test_ConstructorLorg_eclipse_swt_widgets_WidgetI() {
@@ -226,5 +236,24 @@ protected void processEvents(int timeoutMs, BooleanSupplier condition) throws In
 	}
 }
 
+protected void assertNotExists(Widget[] widgetTable, Widget w) {
+	for (Widget widget : widgetTable) {
+		if(widget == w) {
+			fail("Widget table leaks: " + w);
+		}
+	}
+}
+
+protected static Widget[] getWidgetTable(Display display) {
+	try {
+		Field field = Display.class.getDeclaredField("widgetTable");
+		field.setAccessible(true);
+		Widget[] widgetTable = (Widget[]) field.get(display);
+		return widgetTable;
+	} catch (Throwable t) {
+		t.printStackTrace();
+		return null;
+	}
+}
 
 }