mesa: update derived framebuffer state in GetMultisamplefv

This makes sure that ctx->DrawBuffer->Visual.samples is up-to-date.

Reviewed-by: Eric Anholt <eric@anholt.net>

src/mesa/main/multisample.c

@@ -30,6 +30,7 @@
 #include "main/mtypes.h"
 #include "main/fbobject.h"
 #include "main/glformats.h"
+#include "main/state.h"
 
 
 /**
@@ -73,6 +74,10 @@ _mesa_GetMultisamplefv(GLenum pname, GLuint index, GLfloat * val)
 {
    GET_CURRENT_CONTEXT(ctx);
 
+   if (ctx->NewState & _NEW_BUFFERS) {
+      _mesa_update_state(ctx);
+   }
+
    switch (pname) {
    case GL_SAMPLE_POSITION: {
       if (index >= ctx->DrawBuffer->Visual.samples) {