From 3ac29fae435fdb3a8ba7e7297591e6bf2e187d27 Mon Sep 17 00:00:00 2001
From: Soonho Kong <soonhok@cs.cmu.edu>
Date: Sun, 29 Mar 2015 23:06:22 -0400
Subject: [PATCH] fix(util/lua.cpp): 'implicit conversion of nullptr constant
 to bool' warning

clang-3.6.0 generated the following warning:

/Users/soonhok/work/lean/src/util/lua.cpp:49:12: warning: implicit conversion of nullptr constant to 'bool' [-Wnull-conversion]
    return nullptr;
    ~~~~~~ ^~~~~~~
           false
---
 src/util/lua.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/util/lua.cpp b/src/util/lua.cpp
index 69a2cc914..999fa508d 100644
--- a/src/util/lua.cpp
+++ b/src/util/lua.cpp
@@ -43,10 +43,10 @@ bool testudata(lua_State * L, int ud, char const * tname) {
             if (!lua_rawequal(L, -1, -2))
                 p = nullptr;
             lua_pop(L, 2);
-            return p;
+            return p != nullptr;
         }
     }
-    return nullptr;  // value is not a userdata with a metatable
+    return false;  // value is not a userdata with a metatable
 }
 
 int load(lua_State * L, lua_Reader reader, void * data, char const * source) {