Also cope with intermittend DisposedExceptions

...while waiting for the .uno:PrintPreview request to be processed, see
5b5c52a3 "Try make this more robust in slow
environments."  (However, to avoid an endless loop in case DisposedExceptions
are caused by a crash of soffice.bin, cap the loop at 10 sec.)

Change-Id: I13518eea46deb68731604ef08461bad5bb5f7cdf

qadevOOo/tests/java/mod/_sc/ScAccessiblePageHeader.java

@@ -39,6 +39,7 @@ import com.sun.star.frame.XController;
 import com.sun.star.frame.XDispatch;
 import com.sun.star.frame.XDispatchProvider;
 import com.sun.star.frame.XModel;
+import com.sun.star.lang.DisposedException;
 import com.sun.star.lang.XMultiServiceFactory;
 import com.sun.star.sheet.XHeaderFooterContent;
 import com.sun.star.sheet.XSpreadsheet;
@@ -138,12 +139,13 @@ public class ScAccessiblePageHeader extends TestCase {
         AccessibilityTools at = new AccessibilityTools();
 
         XInterface oObj = null;
-        for (;;) {
+        for (int i = 0;; ++i) {
             try {
                 Thread.sleep(500);
             } catch (InterruptedException e) {
                 throw new RuntimeException(e);
             }
+            try {
                 XWindow xWindow = AccessibilityTools.getCurrentWindow( (XMultiServiceFactory) Param.getMSF(), aModel);
                 XAccessible xRoot = AccessibilityTools.getAccessibleObject(xWindow);
                 if (xRoot != null) {
@@ -155,6 +157,13 @@ public class ScAccessiblePageHeader extends TestCase {
                         break;
                     }
                 }
+            } catch (DisposedException e) {
+                log.println("Ignoring DisposedException");
+            }
+            if (i == 20) { // give up after 10 sec
+                throw new RuntimeException(
+                    "Couldn't get AccessibleRoot.HEADER object");
+            }
             log.println("No HEADER found yet, retrying");
         }