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());
         }
 

test/unit/utSortByPType.cpp

@@ -43,6 +43,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 #include "Common/ScenePreprocessor.h"
 #include "PostProcessing/SortByPTypeProcess.h"
 #include <assimp/scene.h>
+#include <assimp/postprocess.h>
 
 using namespace std;
 using namespace Assimp;
@@ -202,3 +203,9 @@ TEST_F(SortByPTypeProcessTest, SortByPTypeStep) {
         }
     }
 }
+
+TEST_F(SortByPTypeProcessTest, issue389327770Test) {
+    Assimp::Importer importer;
+    const aiScene *scene = importer.ReadFile(ASSIMP_TEST_MODELS_DIR "/fuzzer_data/clusterfuzz-testcase-minimized-assimp_fuzzer-4751812606885888", aiProcessPreset_TargetRealtime_Fast);
+    EXPECT_NE(nullptr, scene);
+}