tdf#125297 List Format wrongly applied to text pasted

regression from
    commit f4ea84ff
    Date:   Thu Apr 25 16:35:14 2019 +0200
    tdf#119650 slow saving spreadsheet with comments, part 1

Change-Id: I91b3c009fb8b6739e98537de227ab563828b9c80
Reviewed-on: https://gerrit.libreoffice.org/72842
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

editeng/source/outliner/outliner.cxx

@@ -410,7 +410,11 @@ void Outliner::SetText( const OUString& rText, Paragraph* pPara )
     sal_Int32 nPara = pParaList->GetAbsPos( pPara );
 
     if (pEditEngine->GetText( nPara ) == rText)
-        return; // do nothing
+    {
+        // short-circuit logic to improve performance
+        bFirstParaIsEmpty = false;
+        return;
+    }
 
     bool bUpdate = pEditEngine->GetUpdateMode();
     pEditEngine->SetUpdateMode( false );