From dd7340e5f75f60deeb1ce37b35440a111664fb68 Mon Sep 17 00:00:00 2001
From: Alex Smith <alex.smith@etas.com>
Date: Mon, 2 Jan 2023 17:38:26 +0000
Subject: [PATCH] Avoid dereferencing nullptr C-style strings

Added runtime checks for C-style strings (char*) being nullptr during matching and serialization.

This fix prevents nullptr dereferences in the case that the null character pointer (as opposed to the null nullptr_t) is expected and in the case that a non-null string is expected but nullptr is actually passed.
---
 include/turtle/matcher.hpp | 7 ++++++-
 include/turtle/stream.hpp  | 8 +++++++-
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/include/turtle/matcher.hpp b/include/turtle/matcher.hpp
index 7854d77..fc20a22 100644
--- a/include/turtle/matcher.hpp
+++ b/include/turtle/matcher.hpp
@@ -39,7 +39,12 @@ class matcher<const char*, const char*>
 {
 public:
     explicit matcher(const char* expected) : expected_(expected) {}
-    bool operator()(const char* actual) { return std::strcmp(actual, expected_) == 0; }
+    bool operator()(const char* actual)
+    {
+        if (nullptr == actual || nullptr == expected_)
+            return actual == expected_;
+        return std::strcmp(actual, expected_) == 0;
+    }
     friend std::ostream& operator<<(std::ostream& s, const matcher& m) { return s << mock::format(m.expected_); }
 
 private:
diff --git a/include/turtle/stream.hpp b/include/turtle/stream.hpp
index 52991ed..e3bf273 100644
--- a/include/turtle/stream.hpp
+++ b/include/turtle/stream.hpp
@@ -106,7 +106,13 @@ namespace detail {
     {
         s << '"' << str << '"';
     }
-    inline void serialize(stream& s, const char* const str) { s << '"' << str << '"'; }
+    inline void serialize(stream& s, const char* const str)
+    {
+        if (nullptr != str)
+            s << '"' << str << '"';
+        else
+            s << "nullptr";
+    }
     inline void serialize(stream& s, unsigned char c) { s << static_cast<int>(c); }
 } // namespace detail
 } // namespace mock