bugfix: empty source side effects

src/ce_editor.pas

@@ -228,6 +228,9 @@ begin
   begin
     mainForm.docChangeNotify(Self, editorIndex);
 
+
+    if ed.Lines.Count > 0 then
+    begin
       mainForm.MessageWidget.Clear;
       lex( ed.Lines.Text, tokLst );
 
@@ -239,6 +242,7 @@ begin
       md := getModuleName(tokLst);
       if md = '' then md := extractFileName(ed.fileName);
       pageControl.ActivePage.Caption := md;
+    end;
 
     mainForm.MessageWidget.scrollToBack;
     tokLst.Clear;