* The displist would be uninitialized when nurbs bezieru/v was set and the order wasnt 3 or 4. add a function that checks nurbs can produce a valid line. check_valid_nurb_u/v

* when check_valid_nurb_u/v fails, no curve is allocated or drawn.
* knotsu/v could be NULL but some functions didn't check for this, make sure this is checked for everywhere.
* The interface didnt change check the order when the bezier u/v flag was set, added functions clamp_nurb_order_u/v that takes into accound the number of points and the bezier u/v flag.

1 files changed, 4 insertions, 4 deletions

diff --git a/source/blender/src/buttons_editing.c b/source/blender/src/buttons_editing.c
index 8a37f713164..6e57736845e 100644
--- a/source/blender/src/buttons_editing.c
+++ b/source/blender/src/buttons_editing.c
@@ -3106,11 +3106,13 @@ void do_curvebuts(unsigned short event)
 						if(event<B_UNIFV) {
 							nu->flagu &= 1;
 							nu->flagu += ((event-B_UNIFU)<<1);
+							clamp_nurb_order_u(nu);
 							makeknots(nu, 1, nu->flagu>>1);
 						}
 						else if(nu->pntsv>1) {
 							nu->flagv &= 1;
 							nu->flagv += ((event-B_UNIFV)<<1);
+							clamp_nurb_order_v(nu);
 							makeknots(nu, 2, nu->flagv>>1);
 						}
 					}
@@ -3148,13 +3150,11 @@ void do_curvebuts(unsigned short event)
 		if(G.obedit) {
 			nu= get_actNurb();
 			if(nu && (nu->type & 7)==CU_NURBS ) {
-				if(nu->orderu>nu->pntsu) {
-					nu->orderu= nu->pntsu;
+				if(clamp_nurb_order_u(nu)) {
 					scrarea_queue_winredraw(curarea);
 				}
 				makeknots(nu, 1, nu->flagu>>1);
-				if(nu->orderv>nu->pntsv) {
-					nu->orderv= nu->pntsv;
+				if(clamp_nurb_order_v(nu)) {
 					scrarea_queue_winredraw(curarea);
 				}
 				makeknots(nu, 2, nu->flagv>>1);