Changing cursor (the picture of the mouse) is not immediately applied, and only becomes visible when mouse moves (or another mouse event, eg. button press/release).

My use case is to change the cursor while holding LMB when hovering a button. The observed behavior is that the cursor was changing after next event, eg. pressed cursor visible when not holding a button, and released cursor visible while holding a button, the exact opposite of the intend.

This issue was observed on windows 10, with glfw 9352d8f (2026-01-12).

My solution is to send new message after changing the cursor:

	void Window::cursor(Holder<Cursor> &&c)
	{
		WindowImpl *impl = (WindowImpl *)this;
		if (+impl->currentCursor == +c)
			return;

		if (c)
			glfwSetCursor(impl->window, getCursor(+c));
		else
			glfwSetCursor(impl->window, nullptr);
		impl->currentCursor = std::move(c);

		// force glfw to update the cursor
		cageGlfwPokeCursor(this);
	}


	void cageGlfwPokeCursor(Window *w)
	{
		//double x = 0, y = 0;
		//glfwGetCursorPos(impl->window, &x, &y);
		//glfwSetCursorPos(impl->window, x + 1, y);
		//glfwSetCursorPos(impl->window, x, y);
#ifdef _WIN32
		HWND hwnd = getWindowHwnd(w);
		SendMessage(hwnd, WM_SETCURSOR, (WPARAM)hwnd, MAKELPARAM(HTCLIENT, WM_MOUSEMOVE));
#endif
	}

This solves the problem. My understanding is that this message requests the application to update the cursor, as if it just entered the client area. I am unsure if there are any undesirable side effects.