source/blender/blenkernel/CMakeLists.txt

@@ -833,6 +833,7 @@ if(WITH_GTESTS)
     intern/lib_id_test.cc
     intern/lib_remap_test.cc
     intern/nla_test.cc
+    intern/node_test.cc
     intern/tracking_test.cc
   )
   set(TEST_INC

source/blender/blenkernel/intern/node_test.cc

@@ -0,0 +1,96 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later
+ * Copyright 2022 Blender Foundation. */
+
+#include "testing/testing.h"
+
+#include "MEM_guardedalloc.h"
+
+#include "BLI_listbase.h"
+#include "BLI_string.h"
+
+#include "BKE_callbacks.h"
+#include "BKE_context.h"
+#include "BKE_idtype.h"
+#include "BKE_lib_id.h"
+#include "BKE_main.h"
+#include "BKE_main_namemap.h"
+#include "BKE_node.h"
+#include "BKE_node_runtime.hh"
+#include "BKE_node_tree_update.h"
+
+#include "DNA_ID.h"
+#include "DNA_node_types.h"
+
+#include "RNA_define.h"
+
+#include "CLG_log.h"
+
+namespace blender::bke::node::tests {
+
+struct NodeTreeTestContext {
+  Main *bmain = nullptr;
+  bContext *C = nullptr;
+
+  NodeTreeTestContext()
+  {
+    BKE_idtype_init();
+    bmain = BKE_main_new();
+    C = CTX_create();
+  }
+  ~NodeTreeTestContext()
+  {
+    CTX_free(C);
+    BKE_main_free(bmain);
+  }
+};
+
+class NodeTreeTest : public testing::Test {
+ public:
+  static void SetUpTestSuite()
+  {
+    CLG_init();
+    BKE_callback_global_init();
+    RNA_init();
+    BKE_node_system_init();
+  }
+  static void TearDownTestSuite()
+  {
+    RNA_exit();
+    BKE_node_system_exit();
+    BKE_callback_global_finalize();
+    CLG_exit();
+  }
+
+  void TearDown() override
+  {
+  }
+};
+
+/* Regression test: node groups with trees with undefined type could crash on update. */
+TEST_F(NodeTreeTest, NT_undefined_node_group_update)
+{
+  NodeTreeTestContext ctx;
+
+  /* Invalid idname that results in an "undefined" tree type. */
+  bNodeTree *group_tree = ntreeAddTree(ctx.bmain, "GroupTree", "???");
+  EXPECT_NE(group_tree, nullptr);
+  EXPECT_EQ(group_tree->typeinfo, &NodeTreeTypeUndefined);
+
+  /* Node tree with a node group linking to the undefined tree. */
+  bNodeTree *node_tree = ntreeAddTree(ctx.bmain, "NodeTree", "GeometryNodeTree");
+  EXPECT_NE(node_tree, nullptr);
+  EXPECT_STREQ(node_tree->typeinfo->idname, "GeometryNodeTree");
+  bNode *group_node = nodeAddNode(ctx.C, node_tree, "GeometryNodeGroup");
+  EXPECT_NE(group_node, nullptr);
+  EXPECT_STREQ(group_node->typeinfo->idname, "GeometryNodeGroup");
+  group_node->id = &group_tree->id;
+
+  EXPECT_NE(group_tree->runtime, nullptr);
+  bNodeTreeRuntime *rt = static_cast<bNodeTreeRuntime *>(group_tree->runtime);
+  BKE_ntree_update_tag_all(group_tree);
+  EXPECT_NE(rt->changed_flag, 0);
+
+  BKE_ntree_update_main(ctx.bmain, nullptr);
+}
+
+}  // namespace blender::bke::node::tests

source/blender/blenkernel/intern/node_tree_anonymous_attributes.cc

@@ -23,6 +23,11 @@ static const aal::RelationsInNode &get_relations_in_node(const bNode &node, Reso
 {
   if (node.is_group()) {
     if (const bNodeTree *group = reinterpret_cast<const bNodeTree *>(node.id)) {
+      /* Undefined tree types have no relations. */
+      if (!ntreeIsRegistered(group)) {
+        return scope.construct<aal::RelationsInNode>();
+      }
+
       BLI_assert(group->runtime->anonymous_attribute_relations);
       return *group->runtime->anonymous_attribute_relations;
     }