Fix leak (#5762)

* Fix leak

* Update utLogger.cpp

code/Common/Assimp.cpp

@@ -359,20 +359,25 @@ void CallbackToLogRedirector(const char *msg, char *dt) {
     s->write(msg);
 }
 
+static LogStream *DefaultStream = nullptr;
+
 // ------------------------------------------------------------------------------------------------
 ASSIMP_API aiLogStream aiGetPredefinedLogStream(aiDefaultLogStream pStream, const char *file) {
     aiLogStream sout;
 
     ASSIMP_BEGIN_EXCEPTION_REGION();
-    LogStream *stream = LogStream::createDefaultStream(pStream, file);
-    if (!stream) {
+    if (DefaultStream == nullptr) {
+        DefaultStream = LogStream::createDefaultStream(pStream, file);
+    }
+    
+    if (!DefaultStream) {
         sout.callback = nullptr;
         sout.user = nullptr;
     } else {
         sout.callback = &CallbackToLogRedirector;
-        sout.user = (char *)stream;
+        sout.user = (char *)DefaultStream;
     }
-    gPredefinedStreams.push_back(stream);
+    gPredefinedStreams.push_back(DefaultStream);
     ASSIMP_END_EXCEPTION_REGION(aiLogStream);
     return sout;
 }

fuzz/assimp_fuzzer.cc

@@ -47,7 +47,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 using namespace Assimp;
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t dataSize) {
-    aiLogStream stream = aiGetPredefinedLogStream(aiDefaultLogStream_STDOUT,NULL);
+    aiLogStream stream = aiGetPredefinedLogStream(aiDefaultLogStream_STDOUT, nullptr);
     aiAttachLogStream(&stream);
 
     Importer importer;

test/CMakeLists.txt

@@ -100,6 +100,7 @@ SET( COMMON
   unit/Common/utBase64.cpp
   unit/Common/utHash.cpp
   unit/Common/utBaseProcess.cpp
+  unit/Common/utLogger.cpp
 )
 
 SET(Geometry 

test/unit/Common/utLogger.cpp

@@ -0,0 +1,52 @@
+/*
+---------------------------------------------------------------------------
+Open Asset Import Library (assimp)
+---------------------------------------------------------------------------
+
+Copyright (c) 2006-2024, assimp team
+
+All rights reserved.
+
+Redistribution and use of this software in source and binary forms,
+with or without modification, are permitted provided that the following
+conditions are met:
+
+* Redistributions of source code must retain the above
+copyright notice, this list of conditions and the
+following disclaimer.
+
+* Redistributions in binary form must reproduce the above
+copyright notice, this list of conditions and the
+following disclaimer in the documentation and/or other
+materials provided with the distribution.
+
+* Neither the name of the assimp team, nor the names of its
+contributors may be used to endorse or promote products
+derived from this software without specific prior
+written permission of the assimp team.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+---------------------------------------------------------------------------
+*/
+
+#include "UnitTestPCH.h"
+#include <assimp/Importer.hpp>
+
+using namespace Assimp;
+class utLogger : public ::testing::Test {};
+
+TEST_F(utLogger, aiGetPredefinedLogStream_leak_test) {
+    aiLogStream stream1 = aiGetPredefinedLogStream(aiDefaultLogStream_STDOUT, nullptr);
+    aiLogStream stream2 = aiGetPredefinedLogStream(aiDefaultLogStream_STDOUT, nullptr);
+    ASSERT_EQ(stream1.callback, stream2.callback);
+}