fixed an assertion

src/mesa/swrast/s_buffers.c

@@ -1,4 +1,4 @@
-/* $Id: s_buffers.c,v 1.4 2001/01/24 00:04:59 brianp Exp $ */
+/* $Id: s_buffers.c,v 1.5 2001/02/13 23:58:38 brianp Exp $ */
 
 /*
  * Mesa 3-D graphics library
@@ -123,7 +123,8 @@ clear_color_buffer(GLcontext *ctx)
    }
    else {
       /* Color index mode */
-      ASSERT(ctx->Color.IndexMask == ~0);
+      ASSERT((ctx->Color.IndexMask & ((1 << ctx->Visual.indexBits) - 1))
+             == ((1 << ctx->Visual.indexBits) - 1));
       if (ctx->Visual.indexBits == 8) {
          /* 8-bit clear */
          GLubyte span[MAX_WIDTH];