Made it possible to build SDL from a fresh checkout without any additional steps.
The trick is that if you're using configure and you don't want to have SDL_config.h and SDL_revision.h to show up as modified, you need to configure and build from a separate directory.
You also need to include SDL_revision.h directly if you want to use the SDL_REVISION constant, as a side effect of these changes.
/* Test program to compare the compile-time version of SDL with the linked
version of SDL
*/
#include <stdio.h>
#include <stdlib.h>
#include "SDL.h"
#include "SDL_revision.h"
int
main(int argc, char *argv[])
{
SDL_version compiled;
SDL_version linked;
#if SDL_VERSION_ATLEAST(1, 3, 0)
printf("Compiled with SDL 1.3 or newer\n");
#else
printf("Compiled with SDL older than 1.3\n");
#endif
SDL_VERSION(&compiled);
printf("Compiled version: %d.%d.%d (%s)\n",
compiled.major, compiled.minor, compiled.patch, SDL_REVISION);
SDL_GetVersion(&linked);
printf("Linked version: %d.%d.%d (%s)\n",
linked.major, linked.minor, linked.patch, SDL_GetRevision());
SDL_Quit();
return (0);
}