Add regression test for issue 321
diff --git a/models/regression/unassigned-skeleton.gltf b/models/regression/unassigned-skeleton.gltf
new file mode 100644
index 0000000..6a977e5
--- /dev/null
+++ b/models/regression/unassigned-skeleton.gltf
@@ -0,0 +1,267 @@
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+ }
+ ],
+ "meshes": [
+ {
+ "name": "mesh_0",
+ "primitives": [
+ {
+ "attributes": {
+ "COLOR_0": 3,
+ "JOINTS_0": 6,
+ "NORMAL": 5,
+ "POSITION": 2,
+ "TEXCOORD_0": 4,
+ "WEIGHTS_0": 7
+ },
+ "indices": 1,
+ "mode": 4
+ }
+ ]
+ }
+ ],
+ "nodes": [
+ {
+ "mesh": 0,
+ "name": "mesh_0",
+ "skin": 0
+ },
+ {
+ "children": [
+ 2
+ ],
+ "name": "bone_1",
+ "translation": [
+ 0.0,
+ 1.0,
+ 0.0
+ ]
+ },
+ {
+ "name": "bone_2"
+ },
+ {
+ "name": "bone_3"
+ }
+ ],
+ "scene": 0,
+ "scenes": [
+ {
+ "nodes": [
+ 0,
+ 1,
+ 3
+ ]
+ }
+ ],
+ "skins": [
+ {
+ "inverseBindMatrices": 0,
+ "joints": [
+ 3,
+ 1,
+ 2
+ ],
+ "name": "mesh_0",
+ "0skeleton": -1
+ }
+ ]
+}
diff --git a/tests/tester.cc b/tests/tester.cc
index 0b617b2..c8acf43 100644
--- a/tests/tester.cc
+++ b/tests/tester.cc
@@ -436,6 +436,36 @@
}
+TEST_CASE("empty-skeleton-id", "[issue-321]") {
+
+ tinygltf::Model model;
+ tinygltf::TinyGLTF ctx;
+ std::string err;
+ std::string warn;
+
+ bool ret = ctx.LoadASCIIFromFile(&model, &err, &warn, "../models/regression/unassigned-skeleton.gltf");
+ if (!err.empty()) {
+ std::cerr << err << std::endl;
+ }
+ REQUIRE(true == ret);
+
+ REQUIRE(model.skins.size() == 1);
+ REQUIRE(model.skins[0].skeleton == -1); // unassigned
+
+ std::stringstream os;
+
+ ctx.WriteGltfSceneToStream(&model, os, false, false);
+
+ // use nlohmann json
+ nlohmann::json j = nlohmann::json::parse(os.str());
+
+ // Ensure `skeleton` property is not written to .gltf(was serialized as -1)
+ REQUIRE(1 == j["skins"].size());
+ REQUIRE(j["skins"][0].is_object());
+ REQUIRE(j["skins"][0].count("skeleton") == 0);
+
+}
+
#ifndef TINYGLTF_NO_FS
TEST_CASE("expandpath-utf-8", "[pr-226]") {
