#36 Bug in WriteStr with $O+ (optimizations on)

[Anonymous]

When using optimization (Delphi 6), there's a strange behaviour with data buffer when calling WriteStr.
Looks like the buffer passed to Windows.WriteFile in WriteAsync is not valid long enough.. for some compiler's obscure reasons...

I find it by making a dichotomy with $O+ / $O- options in CPort.pas :)

Inlining WriteStrAsync in WriteStr (I removed the AnsiString cast too) seems to solve the problem, but I couldn't get a clean understanding of this problem.

A cleanerr way to solve this could be to allocate a buffer on the heap in WriteStr, to ensure that buffer stays here during the writefile operation

[Brian Gochnauer]

Change Function WriteStrAsync to; and see what happens.

[code]
function TCustomComPort.WriteStrAsync(const Str: string; var AsyncPtr: PAsync): Integer;
var sa : Ansistring;
begin
if Length(Str) > 0 then
begin
sa := AnsiString(str);
Result := WriteAsync(Sa[1], Length(Str), AsyncPtr);
sa := ''; //keep optimization from freeing stack on sa variable
end
else
Result := 0;
end;

[/code]