commit 4d2eb637a20e4fdf5d5f6c0ea4d4627894594661
Author: Brian <brian@yutani.localnet.net>
Date:   Thu Mar 15 11:16:41 2007 -0600

    no-op clear if buffer width or height is zero (bug 7205)

diff --git a/src/mesa/main/buffers.c b/src/mesa/main/buffers.c
index 0e3ed15..11bd173 100644
--- a/src/mesa/main/buffers.c
+++ b/src/mesa/main/buffers.c
@@ -140,6 +140,9 @@ _mesa_Clear( GLbitfield mask )
       return;
    }
 
+   if (ctx->DrawBuffer->Width == 0 || ctx->DrawBuffer->Height == 0)
+      return;
+
    if (ctx->RenderMode == GL_RENDER) {
       GLbitfield bufferMask;