Hello Mirek

This is a very simple test code to force the problem:

GUI_APP_MAIN
{
	WithMain<TopWindow> dlg;
	
	CtrlLayout(dlg, "Memory test");
	
	dlg.butTest.WhenAction = []{
		try {
			Buffer<int> data;
			data.Alloc(123456789012, 0);
			
			PromptOK("Memory is alloc");
		} catch (const std::bad_alloc& e) {
        		Exclamation("Caught bad_alloc");
		}
	};
	
	dlg.Execute();
}

And this is the change in U++:

void OutOfMemoryPanic(size_t size)
{
	throw std::bad_alloc();
	
	/*char h[200];
	snprintf(h, 200, "Out of memory!\nU++ allocated memory: %d KB", MemoryUsedKb());
	Panic(h);*/
}

When pushing the button 5 times, no problem happens. Visually monitoring the Windows Task Manager, MemoryTest.exe seems to use the same memory all the time.
However, pushing the button one more time, MemoryLimitKb breached! Panic appears. It happens the same in debug and in release.

#include <CtrlLib/CtrlLib.h>

using namespace Upp;

GUI_APP_MAIN
{
	TopWindow win;
	win.Title("Testing");
	win.WhenClose << [] {
		try {
			for(;;) {
				byte *data = new byte[1024 * 4096];
				for(int i = 0; i < 1024; i++)
					data[i * 4096] = 1;
			}
		} catch (const std::bad_alloc&) {
			Exclamation("Caught bad_alloc");
		}
	};
	win.Run();
}