[SOLVED]Memory leak when using HTML tags, FpSpreadsheet 2.0
lazarus / 49-FPSpreadsheet

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Russ · 2025-09-16 12:18

I have an application which uses a TsWorkbookTabControl with a
TsWorkseetGrid and a TsWorkbookSource. Extensive use is made HTML tags
for text formatting. I have noticed that simply clicking on a cell
that uses such formatting results in a memory leak.

This was traced to unit fpsHTMLUtils, function TsHTMLComposer.Exec(),
line 1060 where prevFnt is created but never released. Enclosing the
rest of the function in a Try-Finally where prevFnt is freed solves
the problem. The patch is attached.

I tried to make a simple example app to illustrate the problem, but
even though I used HTML tags, TsHTMLComposer.Exec() never gets called.
I even tried testing with the fpsgrids example app, which uses rich
text, and again TsHTMLComposer.Exec() never gets called, so I have no
idea why there is different behavior with my code.

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wp · 2025-09-16 18:26

Thanks for reporting. Applied your patch.

Here is a small test project to demonstrate the issue before and its
solution after applying the patch (requires "Use Heaptrc unit" in
project options):
Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i program
project1;uses  SysUtils, fpSpreadsheet, fpsTypes, xlsxOOXML,
fpsHTMLUtils;var  wbook: TsWorkbook;  wsheet: TsWorksheet;  cell:
PCell;  s: String;begin  wbook := TsWorkbook.create;  try    wsheet :=
wbook.AddWorksheet('Page');    cell := wsheet.WriteTextAsHTML(0, 0,
'<b>bold</b> <i>italic</i> normal');    RichTextToHTML(wbook,
wsheet.ReadCellFont(cell),      cell^.UTF8StringValue,
cell^.RichTextParams, s);    WriteLn(s);//    wbook.WriteToFile('rtf-
cell.xlsx', true);  finally    wbook.Free;  end;end.