fix: wrong BOM characters written to grid export files, when encoding is set to "UTF-8 BOM" for instance

ansgarbecker · ansgarbecker · commit f951b78c0e83 · 2026-01-15T20:34:39.000+01:00
diff --git a/source/exportgrid.pas b/source/exportgrid.pas
@@ -699,13 +699,14 @@ procedure TfrmExportGrid.btnOKClick(Sender: TObject);
 
     // Prepare stream
     // Note that TStringStream + TEncoding.UTF8 do not write a BOM (which is nice),
-    // although it should do so according to TUTF8Encoding.GetPreamble.
+    // although it has a property TUTF8Encoding.GetPreamble.
     // Now, only newer Excel versions need that BOM, so we add it explicitly here
     // P.S.: Note the boolean/False parameter for OwnsEncoding, so our global encodings are not destroyed after usage
     S := TStringStream.Create('', Encoding, False);
-    if (CurrentExportFormat = efExcel) and (Encoding = TEncoding.UTF8) and radioOutputFile.Checked then begin
-      Bom := TBytes.Create($EF, $BB, $BF);
-      S.Write(Bom, 3);
+    if radioOutputFile.Checked then begin
+      Bom := Encoding.GetPreamble;
+      if Length(Bom) > 0 then
+        S.WriteBuffer(Bom[0], Length(Bom));
     end;
 
     Header := '';
