Merge pull request godotengine#90504 from smix8/sourcegeo_crash

Fix NavigationMeshSourceGeometryData merge crash

Author: akien-mga

scene/resources/navigation_mesh_source_geometry_data_2d.cpp

@@ -120,6 +120,8 @@ void NavigationMeshSourceGeometryData2D::add_obstruction_outline(const PackedVec
 }
 
 void NavigationMeshSourceGeometryData2D::merge(const Ref<NavigationMeshSourceGeometryData2D> &p_other_geometry) {
+	ERR_FAIL_NULL(p_other_geometry);
+
 	// No need to worry about `root_node_transform` here as the data is already xformed.
 	traversable_outlines.append_array(p_other_geometry->traversable_outlines);
 	obstruction_outlines.append_array(p_other_geometry->obstruction_outlines);

scene/resources/navigation_mesh_source_geometry_data_3d.cpp

@@ -172,6 +172,8 @@ void NavigationMeshSourceGeometryData3D::add_faces(const PackedVector3Array &p_f
 }
 
 void NavigationMeshSourceGeometryData3D::merge(const Ref<NavigationMeshSourceGeometryData3D> &p_other_geometry) {
+	ERR_FAIL_NULL(p_other_geometry);
+
 	// No need to worry about `root_node_transform` here as the vertices are already xformed.
 	const int64_t number_of_vertices_before_merge = vertices.size();
 	const int64_t number_of_indices_before_merge = indices.size();