79a846d486
romain.lacroix For the windows implementation of SDL_ShowMessageBox() : ./src/video/windows/SDL_windowsmessagebox.c:345 WIN_ShowMessageBox() The implementation in 2.0.4 uses "button index" for parameter "id" of function AddDialogButton(). It then expects the value provided in param wParam of function MessageBoxDialogProc() to be a valid index of a button. It uses this value to index in the array of buttons when DialogBoxIndirect() returns (line 474 : *buttonid = buttons[which].buttonid;) However, when dismissing this box with Escape, the return value of DialogBoxIndirect will be SDL_MESSAGEBOX_BUTTON_ESCAPEKEY_DEFAULT (=2) which is not always a valid index of array buttons. When the array buttons has a length less or equal than 2, the memory access is invalid; I can see that the value written to *buttonId is uninitialized memory (random value). The fix I propose : use value "buttonid" (field of button) for parameter "id" of AddDialogButton(), then copy return value of DialogBoxIndirect() in *buttonid. This way, we will not use an out-of-bounds index in array buttons.
Simple DirectMedia Layer
(SDL)
Version 2.0
---
https://www.libsdl.org/
Simple DirectMedia Layer is a cross-platform development library designed
to provide low level access to audio, keyboard, mouse, joystick, and graphics
hardware via OpenGL and Direct3D. It is used by video playback software,
emulators, and popular games including Valve's award winning catalog
and many Humble Bundle games.
More extensive documentation is available in the docs directory, starting
with README.md
Enjoy!
Sam Lantinga (slouken@libsdl.org)