forcepoint#48 null deref

Change-Id: I790fc6dafc0d8c9783b9dddc266b313af2a046d7
Reviewed-on: https://gerrit.libreoffice.org/56463
Tested-by: Jenkins
Reviewed-by: Christian Lohmaier <lohmaier+LibreOffice@googlemail.com>
(cherry picked from commit 6725491c)

sw/source/core/unocore/unoportenum.cxx

@@ -288,16 +288,20 @@ namespace
             ::sw::mark::AnnotationMark* const pAnnotationMark =
                 dynamic_cast< ::sw::mark::AnnotationMark* >(ppMark->get());
 
-            if ( pAnnotationMark == nullptr )
-            {
+            if (!pAnnotationMark)
                 continue;
-            }
 
             const SwPosition& rStartPos = pAnnotationMark->GetMarkStart();
-            if ( rStartPos.nNode == nOwnNode )
-            {
+            if (rStartPos.nNode != nOwnNode)
+                continue;
+
             const SwFormatField* pAnnotationFormatField = pAnnotationMark->GetAnnotationFormatField();
-                assert(pAnnotationFormatField != nullptr);
+            if (!pAnnotationFormatField)
+            {
+                SAL_WARN("sw.core", "missing annotation format field");
+                continue;
+            }
+
             rAnnotationStartArr.insert(
                 std::make_shared<SwAnnotationStartPortion_Impl>(
                         SwXTextField::CreateXTextField(&rDoc,
@@ -305,7 +309,6 @@ namespace
                         rStartPos));
         }
     }
-    }
 }
 
 }