mesa: reject immutable textures in glEGLImageTargetTexture2DOES()

GL_ARB_texture_storage says:

    The commands eglBindTexImage, wglBindTexImageARB, glXBindTexImageEXT or
    EGLImageTargetTexture2DOES are not permitted on an immutable-format
    texture.
    They will generate the following errors:
      - EGLImageTargetTexture2DOES: INVALID_OPERATION
      - eglBindTexImage: EGL_BAD_MATCH
      - wglBindTexImage: ERROR_INVALID_OPERATION
      - glXBindTexImageEXT: BadMatch

Fixing the EGL and GLX cases requires extending the DRI interface,
since setTexBuffer2 doesn't currently return any error information.

Reviewed-by: Brian Paul <brianp@vmware.com>

src/mesa/main/teximage.c

@@ -2692,6 +2692,13 @@ _mesa_EGLImageTargetTexture2DOES (GLenum target, GLeglImageOES image)
    texObj = _mesa_get_current_tex_object(ctx, target);
    _mesa_lock_texture(ctx, texObj);
 
+   if (texObj->Immutable) {
+      _mesa_error(ctx, GL_INVALID_OPERATION,
+		  "glEGLImageTargetTexture2D(texture is immutable)");
+      _mesa_unlock_texture(ctx, texObj);
+      return;
+   }
+
    texImage = _mesa_get_tex_image(ctx, texObj, target, 0);
    if (!texImage) {
       _mesa_error(ctx, GL_OUT_OF_MEMORY, "glEGLImageTargetTexture2D");