Fix: Fix leak when sortbyp failes with exception (#6166)

Co-authored-by: Kim Kulling <kim.kulling@draeger.com>

code/Common/Assimp.cpp

@@ -354,9 +354,10 @@ ASSIMP_API const aiScene *aiApplyCustomizedPostProcessing(const aiScene *scene,
 void CallbackToLogRedirector(const char *msg, char *dt) {
     ai_assert(nullptr != msg);
     ai_assert(nullptr != dt);
-    LogStream *s = (LogStream *)dt;
-
-    s->write(msg);
+    LogStream *stream = (LogStream *)dt;
+    if (stream != nullptr) {
+        stream->write(msg);
+    }
 }
 
 static LogStream *DefaultStream = nullptr;

code/PostProcessing/SortByPTypeProcess.cpp

@@ -136,6 +136,9 @@ void SortByPTypeProcess::Execute(aiScene *pScene) {
     for (unsigned int i = 0; i < pScene->mNumMeshes; ++i) {
         aiMesh *const mesh = pScene->mMeshes[i];
         if (mesh->mPrimitiveTypes == 0) {
+            for (size_t idx = 0; idx < outMeshes.size(); ++idx) {
+                delete outMeshes[idx];
+            }
             throw DeadlyImportError("Mesh with invalid primitive type: ", mesh->mName.C_Str());
         }