fdo#68084: OOXML import: handle exceptions if stream is missing

The bugdoc does not have a styles.xml but a stylesWithEffects.xml,
whatever that may mean.  (the app.xml contains "Microsoft Macintosh Word")

Change-Id: If3d11c5d166dcaf3d94129339559787c20e6db46

package/source/xstor/xstorage.cxx

@@ -2136,7 +2136,11 @@ SotElement_Impl* OStorage::OpenStreamElement_Impl( const OUString& aStreamName,
         if ( !( m_pImpl->m_nStorageMode & embed::ElementModes::WRITE )
           || (( nOpenMode & embed::ElementModes::WRITE ) != embed::ElementModes::WRITE )
           || ( nOpenMode & embed::ElementModes::NOCREATE ) == embed::ElementModes::NOCREATE )
-            throw io::IOException( OSL_LOG_PREFIX, uno::Reference< uno::XInterface >() ); // TODO: access_denied
+        {
+            throw io::IOException("Element does not exist and cannot be "
+                    "created: \"" + aStreamName + "\"",
+                    uno::Reference< uno::XInterface >()); // TODO: access_denied
+        }
 
         // create a new StreamElement and insert it into the list
         pElement = m_pImpl->InsertStream( aStreamName, bEncr );

writerfilter/source/ooxml/OOXMLDocumentImpl.cxx

@@ -54,8 +54,17 @@ OOXMLDocumentImpl::~OOXMLDocumentImpl()
 void OOXMLDocumentImpl::resolveFastSubStream(Stream & rStreamHandler,
                                              OOXMLStream::StreamType_t nType)
 {
-    OOXMLStream::Pointer_t pStream
-        (OOXMLDocumentFactory::createStream(mpStream, nType));
+    OOXMLStream::Pointer_t pStream;
+    try
+    {
+        pStream = OOXMLDocumentFactory::createStream(mpStream, nType);
+    }
+    catch (uno::Exception const& e)
+    {
+        SAL_INFO("writerfilter", "resolveFastSubStream: exception while "
+                "resolving stream " << nType << " : " << e.Message);
+        return;
+    }
     OOXMLStream::Pointer_t savedStream = mpStream;
     mpStream = pStream;