llvmpipe: fix handling of 0 x 0 framebuffer size

Bump up the size to 1 x 1.  This fixes a number of potential failure
points in the code.

See also http://bugs.freedesktop.org/show_bug.cgi?id=61012

diff --git a/src/gallium/drivers/llvmpipe/lp_texture.c b/src/gallium/drivers/llvmpipe/lp_texture.c
index 2e9c6bfe1cacbe1a97970f3f3352c741c3c2163a..ce756c528976ae8fe64f0cada37efeed515ed1d2 100644 (file)
--- a/src/gallium/drivers/llvmpipe/lp_texture.c
+++ b/src/gallium/drivers/llvmpipe/lp_texture.c
@@ -240,8 +240,8 @@ llvmpipe_displaytarget_layout(struct llvmpipe_screen *screen,
    /* Round up the surface size to a multiple of the tile size to
     * avoid tile clipping.
     */
-   const unsigned width = align(lpr->base.width0, TILE_SIZE);
-   const unsigned height = align(lpr->base.height0, TILE_SIZE);
+   const unsigned width = MAX2(1, align(lpr->base.width0, TILE_SIZE));
+   const unsigned height = MAX2(1, align(lpr->base.height0, TILE_SIZE));
    const unsigned width_t = width / TILE_SIZE;
    const unsigned height_t = height / TILE_SIZE;