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Bug 522

Summary:	C++ AV when a TChartListBox is used inside a DLL
Product:	VCL TeeChart	Reporter:	david berneda <david>
Component:	Canvas	Assignee:	Steema Issue Manager <issuemanager>
Status:	IN_PROGRESS ---
Severity:	normal	CC:	narcis, yeray
Priority:	Normal
Version:	131119
Target Milestone:	---
Hardware:	PC
OS:	Windows
URL:	http://www.teechart.net/support/viewtopic.php?f=3&t=14519
Chart Series:	---	Delphi / C++ Builder RAD IDE Version:
Attachments:	XE4 C++ project to reproduce DLL AV

Description david berneda 2013-12-19 04:16:40 EST

Run attached C++ XE4 project, an AV is raised in DLL process.

Suspecting the problem is related to including TeeGDIPlus unit (but not using it) in the dll.

See complete description at url Steema forums topic.

Comment 1 david berneda 2013-12-19 04:18:35 EST

Created attachment 60 [details]
XE4 C++ project to reproduce DLL AV

Comment 2 david berneda 2014-01-15 10:06:50 EST

Tested with XE5 Update 2, cannot reproduce the AV.

Comment 5 david berneda 2014-10-28 12:29:05 EDT

With the latest TeeChart source code (140923) and Studio XE7 C++, it seems its necessary again to initialize Gdiplus in the EXE, like for example:

#include "Winapi.GDIPOBJ.hpp"
#include "Winapi.GDIPAPI.hpp"

//---------------------------------------------------------------------------
USEFORM("UnitEXE1.cpp", FormEXE1);
//---------------------------------------------------------------------------
int WINAPI _tWinMain(HINSTANCE, HINSTANCE, LPTSTR, int)
{
  Gdiplus::GdiplusStartupInput StartupInput;

  StartupInput.DebugEventCallback = 0;
  StartupInput.SuppressBackgroundThread = false;
  StartupInput.SuppressExternalCodecs  = false;
  StartupInput.GdiplusVersion = 1;

  unsigned long gdiplusToken=0;

  Gdiplus::GdiplusStartup(&gdiplusToken, &StartupInput, 0);

	try
	{
		Application->Initialize();
		Application->MainFormOnTaskBar = true;
		Application->CreateForm(__classid(TFormEXE1), &FormEXE1);

....

Comment 6 david berneda 2014-10-30 16:47:13 EDT

I've managed to reproduce the AV issue with clone example projects made in Delphi.

This way I could debug using the Delphi-made TeeChart packages to find the exact source code lines, and I've found a possible fix.

(One DLL using runtime packages, called from an EXE also using runtime packages).

The ideal situation would be an EXE using runtime packages, calling another package instead of a DLL. This would allow using the classes inside the package in a normal way.

The first fix is at TeeGDIPlus.pas unit, at procedure TGDIPlusCanvas.SetCanvas, adding "if IsAvailable then" before calling GetGraphics:

procedure TGDIPlusCanvas.SetCanvas(const ACanvas:TCanvas);
begin
  inherited;

  if IsAvailable then  <------- FIX
     GetGraphics; 

  if Assigned(IXORCanvas) then
     IXORCanvas.ReferenceCanvas:=ACanvas;
end;



Maybe there are more places in TeeGDIPlus unit where this same fix should be applied, I'll keep testing.   This is a very special case that only happens because the code using GDI+ is inside a DLL instead of in a package.