kaisyu
In case of OpenGLES, the sequences of loading and unloading driver library should be like that:
SDL_Init
...
SDL_GL_LoadLibrary
SDL_EGL_LoadLibrary
...
SDL_Quit
...
SDL_GL_UnloadLibrary
SDL_EGL_UnloadLibrary
...
However, according to my test results, the varible '_this->gl_config.driver_loaded' does not allow 'SDL_GL_UnloadLibrary' to call 'SDL_EGL_UnloadLibrary'.
The internal function SDL_EGL_LoadLibrary() did not delete and remove a mostly
uninitialized data structure if loading the library first failed. A later try to
use EGL then skipped initialization and assumed it was previously successful
because the data structure now already existed. This led to at least one crash
in the internal function SDL_EGL_ChooseConfig() because a NULL pointer was
dereferenced to make a call to eglBindAPI().
