Fixed crash if initialization of EGL failed but was tried again later.

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().

build-scripts/raspberrypi-buildbot.sh

@@ -0,0 +1,60 @@
+#!/bin/bash
+
+# This is the script buildbot.libsdl.org uses to cross-compile SDL2 from
+#  x86 Linux to Raspberry Pi.
+
+# The final tarball can be unpacked in the root directory of a RPi,
+#  so the SDL2 install lands in /usr/local. Run ldconfig, and then
+#  you should be able to build and run SDL2-based software on your
+#  Pi. Standard configure scripts should be able to find SDL and
+#  build against it, and sdl2-config should work correctly on the
+#  actual device.
+
+TARBALL="$1"
+if [ -z $1 ]; then
+    TARBALL=sdl-raspberrypi.tar.xz
+fi
+
+OSTYPE=`uname -s`
+if [ "$OSTYPE" != "Linux" ]; then
+    # !!! FIXME
+    echo "This only works on x86 or x64-64 Linux at the moment." 1>&2
+    exit 1
+fi
+
+if [ "x$MAKE" == "x" ]; then
+    NCPU=`cat /proc/cpuinfo |grep vendor_id |wc -l`
+    let NCPU=$NCPU+1
+    MAKE="make -j$NCPU"
+fi
+
+BUILDBOTDIR="raspberrypi-buildbot"
+PARENTDIR="$PWD"
+
+set -e
+set -x
+rm -f $TARBALL
+rm -rf $BUILDBOTDIR
+mkdir -p $BUILDBOTDIR
+pushd $BUILDBOTDIR
+
+SYSROOT="/opt/rpi-sysroot"
+export CC="ccache /opt/rpi-tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian/bin/arm-linux-gnueabihf-gcc --sysroot=$SYSROOT -I$SYSROOT/opt/vc/include -I$SYSROOT/usr/include -I$SYSROOT/opt/vc/include/interface/vcos/pthreads -I$SYSROOT/opt/vc/include/interface/vmcs_host/linux -L$SYSROOT/opt/vc/lib"
+# -L$SYSROOT/usr/lib/arm-linux-gnueabihf"
+# !!! FIXME: shouldn't have to --disable-* things here.
+../configure --with-sysroot=$SYSROOT --host=arm-raspberry-linux-gnueabihf --prefix=$PWD/rpi-sdl2-installed --disable-pulseaudio --disable-esd --disable-video-mir --disable-video-wayland
+$MAKE
+$MAKE install
+# Fix up a few things to a real install path on a real Raspberry Pi...
+perl -w -pi -e "s#$PWD/rpi-sdl2-installed#/usr/local#g;" ./rpi-sdl2-installed/lib/libSDL2.la ./rpi-sdl2-installed/lib/pkgconfig/sdl2.pc ./rpi-sdl2-installed/bin/sdl2-config
+mkdir -p ./usr
+mv ./rpi-sdl2-installed ./usr/local
+
+popd
+tar -cJvvf $TARBALL -C $BUILDBOTDIR usr
+rm -rf $BUILDBOTDIR
+
+set +x
+echo "All done. Final installable is in $TARBALL ...";
+
+