Add a unit test.

test/models/glTF2/IndexOutOfRange/IndexOutOfRange.gltf

@@ -0,0 +1,142 @@
+{
+    "asset": {
+        "generator": "COLLADA2GLTF",
+        "version": "2.0"
+    },
+    "scene": 0,
+    "scenes": [
+        {
+            "nodes": [
+                0
+            ]
+        }
+    ],
+    "nodes": [
+        {
+            "children": [
+                1
+            ],
+            "matrix": [
+                1.0,
+                0.0,
+                0.0,
+                0.0,
+                0.0,
+                0.0,
+                -1.0,
+                0.0,
+                0.0,
+                1.0,
+                0.0,
+                0.0,
+                0.0,
+                0.0,
+                0.0,
+                1.0
+            ]
+        },
+        {
+            "mesh": 0
+        }
+    ],
+    "meshes": [
+        {
+            "primitives": [
+                {
+                    "attributes": {
+                        "NORMAL": 1,
+                        "POSITION": 2
+                    },
+                    "indices": 0,
+                    "mode": 4,
+                    "material": 0
+                }
+            ],
+            "name": "Mesh"
+        }
+    ],
+    "accessors": [
+        {
+            "bufferView": 0,
+            "byteOffset": 0,
+            "componentType": 5123,
+            "count": 36,
+            "max": [
+                255
+            ],
+            "min": [
+                0
+            ],
+            "type": "SCALAR"
+        },
+        {
+            "bufferView": 1,
+            "byteOffset": 0,
+            "componentType": 5126,
+            "count": 24,
+            "max": [
+                1.0,
+                1.0,
+                1.0
+            ],
+            "min": [
+                -1.0,
+                -1.0,
+                -1.0
+            ],
+            "type": "VEC3"
+        },
+        {
+            "bufferView": 1,
+            "byteOffset": 288,
+            "componentType": 5126,
+            "count": 24,
+            "max": [
+                0.5,
+                0.5,
+                0.5
+            ],
+            "min": [
+                -0.5,
+                -0.5,
+                -0.5
+            ],
+            "type": "VEC3"
+        }
+    ],
+    "materials": [
+        {
+            "pbrMetallicRoughness": {
+                "baseColorFactor": [
+                    0.800000011920929,
+                    0.0,
+                    0.0,
+                    1.0
+                ],
+                "metallicFactor": 0.0
+            },
+            "name": "Red"
+        }
+    ],
+    "bufferViews": [
+        {
+            "buffer": 0,
+            "byteOffset": 576,
+            "byteLength": 72,
+            "target": 34963
+        },
+        {
+            "buffer": 0,
+            "byteOffset": 0,
+            "byteLength": 576,
+            "byteStride": 12,
+            "target": 34962
+        }
+    ],
+    "buffers": [
+        {
+            "byteLength": 648,
+            "uri": "IndexOutOfRange.bin"
+        }
+    ]
+}

test/unit/utglTF2ImportExport.cpp

@@ -541,3 +541,31 @@ TEST_F(utglTF2ImportExport, norootnode_issue_3269) {
     const aiScene *scene = importer.ReadFile(ASSIMP_TEST_MODELS_DIR "/glTF2/issue_3269/texcoord_crash.gltf", aiProcess_ValidateDataStructure);
     ASSERT_EQ(scene, nullptr);
 }
+
+#include <assimp/LogStream.hpp>
+#include <assimp/DefaultLogger.hpp>
+
+TEST_F(utglTF2ImportExport, indexOutOfRange) {
+    // The contents of an asset should not lead to an assert.
+    Assimp::Importer importer;
+
+    struct WarningObserver : Assimp::LogStream
+    {
+        bool m_observedWarning = false;
+        void write(const char *message) override
+        {
+            m_observedWarning = m_observedWarning || std::strstr(message, "faces were dropped");
+        }
+    };
+    WarningObserver warningObserver;
+    
+    DefaultLogger::get()->attachStream(&warningObserver);
+    const aiScene *scene = importer.ReadFile(ASSIMP_TEST_MODELS_DIR "/glTF2/IndexOutOfRange/IndexOutOfRange.gltf", aiProcess_ValidateDataStructure);
+    ASSERT_NE(scene, nullptr);
+    ASSERT_NE(scene->mRootNode, nullptr);
+    ASSERT_EQ(scene->mNumMeshes, 1);
+    EXPECT_EQ(scene->mMeshes[0]->mNumFaces, 11);
+    DefaultLogger::get()->detachStream(&warningObserver);
+    EXPECT_TRUE(warningObserver.m_observedWarning);
+}
+