[logging-log4cxx] 01/01: Fix NPE when attempting to cast a null pointer

[rm...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

rmiddleton pushed a commit to branch null-cast-check
in repository https://gitbox.apache.org/repos/asf/logging-log4cxx.git

commit daa8ebbbff92102324e3e03bb6ae8c0508ae65a3
Author: Robert Middleton <ro...@rm5248.com>
AuthorDate: Sun Jan 9 14:38:26 2022 -0500

    Fix NPE when attempting to cast a null pointer
---
 src/main/include/log4cxx/helpers/object.h |  5 +++++
 src/test/cpp/helpers/casttestcase.cpp     | 11 ++++++++++-
 2 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/src/main/include/log4cxx/helpers/object.h b/src/main/include/log4cxx/helpers/object.h
index 18b6728..b8382a5 100644
--- a/src/main/include/log4cxx/helpers/object.h
+++ b/src/main/include/log4cxx/helpers/object.h
@@ -121,6 +121,11 @@ template<typename Ret,
 	bool = std::is_base_of<Type, helpers::Object>::value>
 std::shared_ptr<Ret> cast(const std::shared_ptr<Type>& incoming)
 {
+	if(!incoming)
+	{
+		return std::shared_ptr<Ret>();
+	}
+
 	Ret* casted = reinterpret_cast<Ret*>(const_cast<void*>(incoming->cast(Ret::getStaticClass())));
 
 	if ( casted )
diff --git a/src/test/cpp/helpers/casttestcase.cpp b/src/test/cpp/helpers/casttestcase.cpp
index e7d8f53..4d2e5ab 100644
--- a/src/test/cpp/helpers/casttestcase.cpp
+++ b/src/test/cpp/helpers/casttestcase.cpp
@@ -33,7 +33,7 @@ LOGUNIT_CLASS(CastTestCase)
 	LOGUNIT_TEST_SUITE( CastTestCase );
 	LOGUNIT_TEST(testGoodCast);
 	LOGUNIT_TEST(testBadCast);
-
+	LOGUNIT_TEST(testNullParameter);
 	LOGUNIT_TEST_SUITE_END();
 
 public:
@@ -59,6 +59,15 @@ public:
 		LOGUNIT_ASSERT(!fos);
 	}
 
+	void testNullParameter()
+	{
+		OutputStreamPtr out = nullptr;
+
+		FileOutputStreamPtr fos = log4cxx::cast<FileOutputStream>(out);
+
+		LOGUNIT_ASSERT(!fos);
+	}
+
 };
 
 LOGUNIT_TEST_SUITE_REGISTRATION(CastTestCase);