Fix for bug 32017.

There was some bad recursion introduced recently that caused crashes
when a Material node is the same material as the material itself (e.g.,
if Material.001 has a node with Material.001).

This commit attempt to correct this by keeping track of the material
at the root of the node tree, and doesn't recurse further if it
encounters it again within the nodetree.

Joshua, please review!

2 files changed, 19 insertions, 10 deletions

diff --git a/source/blender/blenkernel/intern/depsgraph.c b/source/blender/blenkernel/intern/depsgraph.c
index 2faa882e3ea..05a2cfee8e6 100644
--- a/source/blender/blenkernel/intern/depsgraph.c
+++ b/source/blender/blenkernel/intern/depsgraph.c
@@ -352,10 +352,11 @@ static void dag_add_driver_relation(AnimData *adt, DagForest *dag, DagNode *node
 static void dag_add_material_driver_relations(DagForest *dag, DagNode *node, Material *ma);
 
 /* recursive handling for material nodetree drivers */
-static void dag_add_material_nodetree_driver_relations(DagForest *dag, DagNode *node, bNodeTree *ntree)
+static void dag_add_material_nodetree_driver_relations(DagForest *dag, DagNode *node, bNodeTree *ntree, Material *rootma)
 {
 	bNode *n;
-	
+	Material *ma;
+
 	/* nodetree itself */
 	if (ntree->adt) {
 		dag_add_driver_relation(ntree->adt, dag, node, 1);
@@ -364,10 +365,13 @@ static void dag_add_material_nodetree_driver_relations(DagForest *dag, DagNode *
 	/* nodetree's nodes... */
 	for (n = ntree->nodes.first; n; n = n->next) {
 		if (n->id && GS(n->id->name) == ID_MA) {
-			dag_add_material_driver_relations(dag, node, (Material *)n->id);
+            ma = (Material *)n->id;
+            if (ma != rootma) {
+                dag_add_material_driver_relations(dag, node, ma);
+            }
 		}
 		else if (n->type == NODE_GROUP && n->id) {
-			dag_add_material_nodetree_driver_relations(dag, node, (bNodeTree *)n->id);
+			dag_add_material_nodetree_driver_relations(dag, node, (bNodeTree *)n->id, rootma);
 		}
 	}
 }
@@ -386,7 +390,7 @@ static void dag_add_material_driver_relations(DagForest *dag, DagNode *node, Mat
 	
 	/* material's nodetree */
 	if (ma->nodetree) {
-		dag_add_material_nodetree_driver_relations(dag, node, ma->nodetree);
+		dag_add_material_nodetree_driver_relations(dag, node, ma->nodetree, ma);
 	}
 }
 
diff --git a/source/blender/blenkernel/intern/material.c b/source/blender/blenkernel/intern/material.c
index 23f197155a1..de2b99fcbf9 100644
--- a/source/blender/blenkernel/intern/material.c
+++ b/source/blender/blenkernel/intern/material.c
@@ -1056,10 +1056,11 @@ int material_in_material(Material *parmat, Material *mat)
 /* ****************** */
 
 /* Update drivers for materials in a nodetree */
-static void material_node_drivers_update(Scene *scene, bNodeTree *ntree, float ctime)
+static void material_node_drivers_update(Scene *scene, bNodeTree *ntree, float ctime, Material *rootma)
 {
 	bNode *node;
-	
+	Material *ma;
+
 	/* nodetree itself */
 	if (ntree->adt && ntree->adt->drivers.first) {
 		BKE_animsys_evaluate_animdata(scene, &ntree->id, ntree->adt, ctime, ADT_RECALC_DRIVERS);
@@ -1069,10 +1070,14 @@ static void material_node_drivers_update(Scene *scene, bNodeTree *ntree, float c
 	for (node = ntree->nodes.first; node; node = node->next) {
 		if (node->id && GS(node->id->name) == ID_MA) {
 			/* TODO: prevent infinite recursion here... */
-			material_drivers_update(scene, (Material *)node->id, ctime);
+            ma = (Material *)node->id;
+            if (ma != rootma) {
+                material_drivers_update(scene, ma, ctime);
+            }
 		}
 		else if (node->type == NODE_GROUP && node->id) {
-			material_node_drivers_update(scene, (bNodeTree *)node->id, ctime);
+			material_node_drivers_update(scene, (bNodeTree *)node->id,
+                                         ctime, rootma);
 		}
 	}
 }
@@ -1094,7 +1099,7 @@ void material_drivers_update(Scene *scene, Material *ma, float ctime)
 	
 	/* nodes */
 	if (ma->nodetree) {
-		material_node_drivers_update(scene, ma->nodetree, ctime);
+		material_node_drivers_update(scene, ma->nodetree, ctime, ma);
 	}
 }