Bug 343634 [Compatibility] IllegalArgumentException (null argument) in WorkbenchPage.installAreaDropSupport() when not calling configureEditorAreaDropListener() in preWindowOpen()

bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchPage.java

diff --git a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchPage.java b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchPage.java
index 2d55f95..8c9c666 100644
--- a/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchPage.java
+++ b/bundles/org.eclipse.ui.workbench/Eclipse UI/org/eclipse/ui/internal/WorkbenchPage.java
@@ -73,6 +73,7 @@
 import org.eclipse.swt.custom.BusyIndicator;
 import org.eclipse.swt.dnd.DND;
 import org.eclipse.swt.dnd.DropTarget;
+import org.eclipse.swt.dnd.DropTargetListener;
 import org.eclipse.swt.program.Program;
 import org.eclipse.swt.widgets.Composite;
 import org.eclipse.swt.widgets.Control;
@@ -2388,10 +2389,13 @@
 	private void installAreaDropSupport(Control control) {
 		if (!dndSupportInstalled) {
 			WorkbenchWindowConfigurer configurer = legacyWindow.getWindowConfigurer();
-			DropTarget dropTarget = new DropTarget(control, DND.DROP_DEFAULT | DND.DROP_COPY
-					| DND.DROP_LINK);
-			dropTarget.setTransfer(configurer.getTransfers());
-			dropTarget.addDropListener(configurer.getDropTargetListener());
+			DropTargetListener dropTargetListener = configurer.getDropTargetListener();
+			if (dropTargetListener != null) {
+				DropTarget dropTarget = new DropTarget(control, DND.DROP_DEFAULT | DND.DROP_COPY
+						| DND.DROP_LINK);
+				dropTarget.setTransfer(configurer.getTransfers());
+				dropTarget.addDropListener(dropTargetListener);
+			}
 			dndSupportInstalled = true;
 		}
 	}