From 218aead649d970177df2a6486a33691400c9c8c0 Mon Sep 17 00:00:00 2001
From: Rusty Conover <rusty@conover.me>
Date: Sun, 26 Jan 2020 10:53:26 -0500
Subject: [PATCH 1/2] debug: Fix crash handling null strings

When internal debug is enabled output null strings as
"(null)" rather than crashing matching glibc's behavior.
---
 src/debug_utils-inl.h | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/debug_utils-inl.h b/src/debug_utils-inl.h
index f24643fbae3ad8..f84d51d8112090 100644
--- a/src/debug_utils-inl.h
+++ b/src/debug_utils-inl.h
@@ -21,7 +21,9 @@ struct ToStringHelper {
                 enable_if<std::is_arithmetic<T>::value, bool>::type,
             typename dummy = bool>
   static std::string Convert(const T& value) { return std::to_string(value); }
-  static std::string Convert(const char* value) { return value; }
+  static std::string Convert(const char* value) {
+    return value ? value : "(null)";
+  }
   static std::string Convert(const std::string& value) { return value; }
   static std::string Convert(bool value) { return value ? "true" : "false"; }
 };

From 6727bc0fcab49e226e074de391d56f23646915c6 Mon Sep 17 00:00:00 2001
From: Rusty Conover <rusty@conover.me>
Date: Sun, 26 Jan 2020 11:43:28 -0500
Subject: [PATCH 2/2] Add test and fix nit.

---
 src/debug_utils-inl.h    | 2 +-
 test/cctest/test_util.cc | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/debug_utils-inl.h b/src/debug_utils-inl.h
index f84d51d8112090..2f6137700d8a37 100644
--- a/src/debug_utils-inl.h
+++ b/src/debug_utils-inl.h
@@ -22,7 +22,7 @@ struct ToStringHelper {
             typename dummy = bool>
   static std::string Convert(const T& value) { return std::to_string(value); }
   static std::string Convert(const char* value) {
-    return value ? value : "(null)";
+    return value != nullptr ? value : "(null)";
   }
   static std::string Convert(const std::string& value) { return value; }
   static std::string Convert(bool value) { return value ? "true" : "false"; }
diff --git a/test/cctest/test_util.cc b/test/cctest/test_util.cc
index 843d16d9f527c6..a38f549f0387dc 100644
--- a/test/cctest/test_util.cc
+++ b/test/cctest/test_util.cc
@@ -281,6 +281,7 @@ TEST(UtilTest, SPrintF) {
   const char* bar = "bar";
   EXPECT_EQ(SPrintF("%s %s", foo, "bar"), "foo bar");
   EXPECT_EQ(SPrintF("%s %s", foo, bar), "foo bar");
+  EXPECT_EQ(SPrintF("%s", nullptr), "(null)");
 
   EXPECT_EQ(SPrintF("[%% %s %%]", foo), "[% foo %]");