fdo#79384 RTF import: allow { without } in style names

This is not valid, but LO 3.4 supported it, so add a workaround...

Change-Id: Ib8eefdf41fe9801db6f7e5873eaa1436518912fb

sw/qa/core/data/rtf/pass/fdo79384.rtf

+{\rtf1
+{\stylesheet
+{\*\cs35\snext35\hich\af5\dbch\af5\loch\f5 Mp{u y{p;}
+}
+\par }

writerfilter/source/rtftok/rtfdocumentimpl.cxx

@@ -956,7 +956,12 @@ int RTFDocumentImpl::resolveChars(char ch)
 
     bool bUnicodeChecked = false;
     bool bSkipped = false;
-    while (!Strm().IsEof() && (m_aStates.top().nInternalState == INTERNAL_HEX || (ch != '{' && ch != '}' && ch != '\\')))
+
+    // Workaround for buggy input: if we're inside a style entry, then ignore
+    // the fact that '{' without a matching '}' is invalid.
+    bool bStyleEntry = m_aStates.top().nDestinationState == DESTINATION_STYLEENTRY;
+
+    while (!Strm().IsEof() && (m_aStates.top().nInternalState == INTERNAL_HEX || ((ch != '{' || bStyleEntry) && ch != '}' && ch != '\\')))
     {
         if (m_aStates.top().nInternalState == INTERNAL_HEX || (ch != 0x0d && ch != 0x0a))
         {