Calling glGetUniformLocation between glNewList and glEndList always returns 0,
even if the variable being requested does not exist in the program.

Occurs with at least swrast and i965.  I tested both mesa 7.8.2 and git master.
Restructuring the program so that the glGetUniformLocation is called outside
of the list makes it work.

For example:

  glNewList(1, GL_COMPILE_AND_EXECUTE);
  var = glGetUniformLocation(program, "something");
  /* var will now be zero, regardless of the program or "something" */
  /* do other stuff */
  glEndList();