Fixed bug 1882 - SDL_GetKeyboardState should return const.

Yuri K. Schlesner

The array returned by SDL_GetKeyboardState is also used internally by SDL to keep track of pressed/released keys and must not be modified, lest weird behaviour occurs. Because of this I believe it's return type should be changed to return a const pointer, which will provide a code indication of that fact.

include/SDL_keyboard.h

@@ -66,13 +66,13 @@ extern DECLSPEC SDL_Window * SDLCALL SDL_GetKeyboardFocus(void);
  *
  *  \b Example:
  *  \code
- *  Uint8 *state = SDL_GetKeyboardState(NULL);
+ *  const Uint8 *state = SDL_GetKeyboardState(NULL);
  *  if ( state[SDL_SCANCODE_RETURN] )   {
  *      printf("<RETURN> is pressed.\n");
  *  }
  *  \endcode
  */
-extern DECLSPEC Uint8 *SDLCALL SDL_GetKeyboardState(int *numkeys);
+extern DECLSPEC const Uint8 *SDLCALL SDL_GetKeyboardState(int *numkeys);
 
 /**
  *  \brief Get the current key modifier state for the keyboard.

src/events/SDL_keyboard.c

@@ -829,7 +829,7 @@ SDL_KeyboardQuit(void)
 {
 }
 
-Uint8 *
+const Uint8 *
 SDL_GetKeyboardState(int *numkeys)
 {
     SDL_Keyboard *keyboard = &SDL_keyboard;