Bug 532631 - getSelectedEncoding(): add disposal check

Change-Id: I26f34020395cf9e5bb45e7ae6d1e7e4e5a4454ba
Signed-off-by: Karsten Thoms <karsten.thoms@karakun.de>
Reviewed-on: https://git.eclipse.org/r/c/platform/eclipse.platform.ui/+/119743
Tested-by: Platform Bot <platform-bot@eclipse.org>
Reviewed-by: Karsten Thoms <karsten.thoms@karakun.com>
diff --git a/bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/dialogs/AbstractEncodingFieldEditor.java b/bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/dialogs/AbstractEncodingFieldEditor.java
index 861f293..93edc99 100644
--- a/bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/dialogs/AbstractEncodingFieldEditor.java
+++ b/bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/dialogs/AbstractEncodingFieldEditor.java
@@ -338,7 +338,8 @@
 	 * @return the currently selected encoding
 	 */
 	protected String getSelectedEncoding() {
-		if (defaultEncodingButton.getSelection()) {
+		if ((!defaultEncodingButton.isDisposed() && defaultEncodingButton.getSelection())
+				|| encodingCombo.isDisposed()) {
 			return defaultEnc;
 		}
 		return encodingCombo.getText();