TSCP: skip empty classification sections

When the user inserts some classification text
into the editbox in the classifcation dialog then
deletes, EditEng is giving us an empty section.

This is to skip it, since it's completely superfluous.

Change-Id: I522f05d0a270cd2bd9892235ad3cb40a88b295ac
Reviewed-on: https://gerrit.libreoffice.org/43888Reviewed-by: Ashod Nakashian <ashnakash@gmail.com>
Tested-by: Ashod Nakashian <ashnakash@gmail.com>

svx/source/dialog/ClassificationDialog.cxx

@@ -166,17 +166,21 @@ std::vector<ClassificationResult> ClassificationDialog::getResult()
 
         ESelection aSelection(rSection.mnParagraph, rSection.mnStart, rSection.mnParagraph, rSection.mnEnd);
         const OUString sDisplayString = m_pEditWindow->pEdEngine->GetText(aSelection);
-        const ClassificationField* pClassificationField = pFieldItem ? dynamic_cast<const ClassificationField*>(pFieldItem->GetField()) : nullptr;
-
-        if (pClassificationField)
-        {
-            aClassificationResults.push_back({ pClassificationField->meType, pClassificationField->msFullClassName, sDisplayString, rSection.mnParagraph });
-        }
-        else
+        if (!sDisplayString.isEmpty())
         {
-            aClassificationResults.push_back({ ClassificationType::TEXT, pClassificationField->msFullClassName, sDisplayString, rSection.mnParagraph });
+            const ClassificationField* pClassificationField = pFieldItem ? dynamic_cast<const ClassificationField*>(pFieldItem->GetField()) : nullptr;
+
+            if (pClassificationField)
+            {
+                aClassificationResults.push_back({ pClassificationField->meType, pClassificationField->msFullClassName, sDisplayString, rSection.mnParagraph });
+            }
+            else
+            {
+                aClassificationResults.push_back({ ClassificationType::TEXT, sDisplayString, sDisplayString, rSection.mnParagraph });
+            }
         }
     }
+
     return aClassificationResults;
 }