Merge pull request #4609 from assimp/kimkulling/fix-issue-4238

Try to fix issue 4238

code/AssetLib/MDL/MDLMaterialLoader.cpp

@@ -449,6 +449,9 @@ void MDLImporter::ParseSkinLump_3DGS_MDL7(
         unsigned int iWidth,
         unsigned int iHeight) {
     std::unique_ptr<aiTexture> pcNew;
+    if (szCurrent == nullptr) {
+        return;
+    }
 
     // get the type of the skin
     unsigned int iMasked = (unsigned int)(iType & 0xF);