fpspreadsheet: (Hopefully) fix missing last character of cell text copied to clipboard as CF_TEXT (see http://forum.lazarus.freepascal.org/index.php/topic,38925.0.html)

git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@6069 8e941d3f-bd1b-0410-a28a-d453659cc2b4

components/fpspreadsheet/source/common/fpspreadsheet.pas

@@ -9499,6 +9499,9 @@ begin
     // indicate that this should be the special clipboard version of the stream.
     clipbook.WriteToStream(AStream, AFormat, AParams + [spClipboard]);
 
+    if AFormat = sfCSV then
+      AStream.WriteByte(0);
+
     // The calling routine which copies the stream to the clipboard requires
     // the stream to be at its beginning.
     AStream.Position := 0;