From af770ef9896c2d2078b3013f6666ffc41f6edf51 Mon Sep 17 00:00:00 2001
From: Chris Jones <cmsj@tenshu.net>
Date: Tue, 17 Feb 2015 15:58:03 +0000
Subject: [PATCH] Don't lua_call evalfn in MJLuaRunString() if it's not a
 function. If it's a string, which means it's an error, NSLog() it

---
 Hammerspoon/MJLua.m | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/Hammerspoon/MJLua.m b/Hammerspoon/MJLua.m
index ecd4ff01f..a9ac697d6 100644
--- a/Hammerspoon/MJLua.m
+++ b/Hammerspoon/MJLua.m
@@ -125,6 +125,13 @@ void MJLuaTeardown(void) {
     lua_State* L = MJLuaState;
     
     lua_rawgeti(L, LUA_REGISTRYINDEX, evalfn);
+    if (!lua_isfunction(L, -1)) {
+        NSLog(@"ERROR: MJLuaRunString doesn't seem to have an evalfn");
+        if (lua_isstring(L, -1)) {
+            NSLog(@"evalfn appears to be a string: %s", lua_tostring(L, -1));
+        }
+        return @"";
+    }
     lua_pushstring(L, [command UTF8String]);
     lua_call(L, 1, 1);