mesa: fix incorrect viewport clamping in _mesa_set_viewport()

A 0 by 0 viewport size is legal.  Don't clamp against lower bound of one.
The error checking earlier in the function prevents negative values.

diff --git a/src/mesa/main/viewport.c b/src/mesa/main/viewport.c
index ead856d32c3148f67a126dabd4fe83bc883e731b..50e0402d2788001c803e0c53d4d890cda0ee3ef3 100644 (file)
--- a/src/mesa/main/viewport.c
+++ b/src/mesa/main/viewport.c
@@ -73,8 +73,8 @@ _mesa_set_viewport(GLcontext *ctx, GLint x, GLint y,
    }
 
    /* clamp width and height to the implementation dependent range */
-   width  = CLAMP(width,  1, (GLsizei) ctx->Const.MaxViewportWidth);
-   height = CLAMP(height, 1, (GLsizei) ctx->Const.MaxViewportHeight);
+   width  = MIN2(width, (GLsizei) ctx->Const.MaxViewportWidth);
+   height = MIN2(height, (GLsizei) ctx->Const.MaxViewportHeight);
 
    ctx->Viewport.X = x;
    ctx->Viewport.Width = width;