Fix comparison of unsigned value against < 0.
diff --git a/src/mesa/main/api_validate.c b/src/mesa/main/api_validate.c
index 326ad6f..e9359db 100644
--- a/src/mesa/main/api_validate.c
+++ b/src/mesa/main/api_validate.c
@@ -147,7 +147,7 @@
 
    vbo_get_minmax_index(ctx, &prim, &ib, &min, &max);
 
-   if (min + basevertex < 0 ||
+   if ((int)(min + basevertex) < 0 ||
        max + basevertex > ctx->Array.ArrayObj->_MaxElement) {
       /* the max element is out of bounds of one or more enabled arrays */
       _mesa_warning(ctx, "glDrawElements() index=%u is "