Fix [#21727] texture in compositor quickly results in crash

Hopefully this is correct - looks like the CompBuf->node pointer was getting left
out of the per-thread copying/localisation.

source/blender/blenkernel/intern/node.c

@@ -2573,6 +2573,8 @@ bNodeTree *ntreeLocalize(bNodeTree *ntree)
 		for(sock= node->outputs.first; sock; sock= sock->next) {
 			
 			sock->new_sock->ns.data= sock->ns.data;
+			compbuf_set_node(sock->new_sock->ns.data, node->new_node);
+			
 			sock->ns.data= NULL;
 			sock->new_sock->new_sock= sock;
 		}

source/blender/nodes/intern/CMP_util.c

@@ -122,6 +122,11 @@ void print_compbuf(char *str, CompBuf *cbuf)
 	
 }
 
+void compbuf_set_node(CompBuf *cbuf, bNode *node)
+{
+	if (cbuf) cbuf->node = node;
+}
+
 /* used for disabling node  (similar code in drawnode.c for disable line) */
 void node_compo_pass_on(bNode *node, bNodeStack **nsin, bNodeStack **nsout)
 {

source/blender/nodes/intern/CMP_util.h

@@ -110,6 +110,7 @@ CompBuf *dupalloc_compbuf(CompBuf *cbuf);
 CompBuf *pass_on_compbuf(CompBuf *cbuf);
 void free_compbuf(CompBuf *cbuf);
 void print_compbuf(char *str, CompBuf *cbuf);
+void compbuf_set_node(struct CompBuf *cbuf, struct bNode *node);
 void node_compo_pass_on(struct bNode *node, struct bNodeStack **nsin, struct bNodeStack **nsout);
 
 CompBuf *get_cropped_compbuf(rcti *drect, float *rectf, int rectx, int recty, int type);