EGL: superb hack around Mesa EGL damaged linking

modules/video_output/Modules.am

@@ -91,6 +91,9 @@ libegl_plugin_la_CFLAGS = $(AM_CFLAGS) \
 	$(EGL_CFLAGS) $(GL_CFLAGS)
 libegl_plugin_la_LIBADD = $(AM_LIBADD) \
 	$(EGL_LIBS) $(GL_LIBS)
+if !HAVE_WIN32
+libegl_plugin_la_LIBADD += -ldl
+endif
 libegl_plugin_la_DEPENDENCIES =
 EXTRA_LTLIBRARIES += libegl_plugin.la
 libvlc_LTLIBRARIES += $(LTLIBegl)

modules/video_output/egl.c

@@ -48,6 +48,10 @@
 # define VLC_RENDERABLE_BIT EGL_OPENGL_BIT
 #endif
 
+#ifdef __unix__
+# include <dlfcn.h>
+#endif
+
 /* Plugin callbacks */
 static int Open (vlc_object_t *);
 static void Close (vlc_object_t *);
@@ -151,6 +155,17 @@ static int Open (vlc_object_t *obj)
     sys->gl.sys = NULL;
     sys->pool = NULL;
 
+    /* XXX Explicit hack!
+     * Mesa EGL plugins (as of version 7.8.2) are not properly linked to
+     * libEGL.so even though they import some of its symbols. This is
+     * typically not a problem. Unfortunately, LibVLC loads plugins as
+     * RTLD_LOCAL so that they do not pollute the namespace. Then the
+     * libEGL symbols are not visible to EGL plugins, and the run-time
+     * linker exits the whole process. */
+#ifdef __unix__
+    dlopen ("libEGL.so", RTLD_GLOBAL|RTLD_LAZY);
+#endif
+
     EGLint major, minor;
     if (eglInitialize (dpy, &major, &minor) != EGL_TRUE)
     {