Bug#793111: OpenGL ES2 support does not work with OpenGL support enabled

[Prof. Dr. Gundolf Kiefer]

Package: libsdl2 (source package)
Version: 2.0.2+dfsg1-6

It appears that in the present version (2.0.2) of libSDL2,
hardware acceleration based on OpenGL ES2 does not to work properly if
both OpenGL and OpenGL ES2 support are compiled in at the same time.

I am using libSDL2 on an embedded Linux board (Cubietruck, A20 SoC,
Mali 400 GPU), running under Debian Jessie, architecture 'armhf'. 

With the stock Debian package, the renderer 'opengles2' is available,
i.e. reported by 'SDL_GetNumRenderDrivers'/'SDL_GetRenderDriverInfo',
but not functional on my system. When selected manually, 'SDL_CreateRenderer'
fails with the SDL error "GLX is not supported".

If I rebuild the package with the only additional configuration option 
'--disable-video-opengl', it works fine.

diff -p libsdl2-2.0.2+dfsg1/debian/rules libsdl2-2.0.2+dfsg1-gk1/debian/rules 
*** libsdl2-2.0.2+dfsg1/debian/rules	Thu Nov 27 18:53:32 2014
--- libsdl2-2.0.2+dfsg1-gk1/debian/rules	Fri Jul  3 17:11:37 2015
*************** confflags = --disable-rpath --enable-sdl
*** 9,14 ****
--- 9,15 ----
              --disable-nas --disable-esd --disable-arts \
              --disable-alsa-shared --disable-pulseaudio-shared \
              --disable-x11-shared --disable-video-directfb \
+             --disable-video-opengl \
              --enable-video-opengles \
              --enable-video-wayland --disable-wayland-shared
  

I am not too familiar with the libSDL2 code, and I am not sure if this
issue can easily be solved upstream. For the time being, I suggest to provide
two alternative binary packages with EITHER OpenGL or OpenGL ES2
enabled and the other disabled.