Hello, I am subclassing a scintilla window and it happens every now and then that I get an OverflowError. I've logged the message and could narrow down that it is a single windows message which causes this trouble. It's WM_ERASEBKGND.
Now the confusing part for me is the following. According to MS WPARAM <https://docs.microsoft.com/en-us/windows/win32/winprog/windows-data-types> is an UINT_PTR which is defined as #if defined(_WIN64) typedef unsigned __int64 UINT_PTR; #else typedef unsigned int UINT_PTR; #endif wintypes.WPARAM is ctypes.c_ulonglong and is of size 8 on my system. I'm on a x64 Windows - so far as good, right? Now when I get this error the message I receive in this situation is always like this. hWnd=197364, msg=20, wParam=*18446744072652653190*, lParam=0 Traceback (most recent call last): File "_ctypes/callbacks.c", line 237, in 'calling callback function' File "<string>", line 121, in new_scintilla2_proc ctypes.ArgumentError: argument 4: <class 'OverflowError'>: int too long to convert I really doubt that 18446744072652653190 is a valid device context but who knows. The question is, why do I even get this OverflowError? If I do wintypes.WPARAM(18446744072652653190) I don't receive an exception and it is a valid 64bit value, isn't it? The code I'm using is this user32 = ctypes.WinDLL('user32', use_last_error=True) LRESULT = wintypes.LPARAM WND_PROC = ctypes.WINFUNCTYPE(LRESULT, wintypes.HWND, wintypes.UINT, wintypes.WPARAM, wintypes.LPARAM) user32.CallWindowProcW.restype = LRESULT user32.CallWindowProcW.argtypes = [WND_PROC, wintypes.HWND, wintypes.UINT, wintypes.WPARAM, wintypes.LPARAM] Any idea what might have caused this? Thank you for reading Eren -- https://mail.python.org/mailman/listinfo/python-list
