# HG changeset patch
# User jbe
# Date 1463406118 -7200
# Node ID 8145293e3f4a9fd3fadaa2fd57633277646e2660
# Parent  5d307886bd89d18ac8f5442f34038873235602b0
Do not use luaL_addchar unless Lua string buffer is on top of stack (possible segmentation fault)

diff -r 5d307886bd89 -r 8145293e3f4a libraries/json/json.c
--- a/libraries/json/json.c	Sun Feb 28 19:16:03 2016 +0100
+++ b/libraries/json/json.c	Mon May 16 15:41:58 2016 +0200
@@ -1312,14 +1312,14 @@
       case JSON_TABLETYPE_OBJECT:
         // finish iteration if all string keys have been processed:
         if (container->pos == container->count) goto json_export_close;
-        // push current string key on top of stack:
-        key = &container->keys[container->pos];
-        lua_pushlstring(L, key->data, key->length);
         // check if the key has already been exported:
         if (!containerkey) {
           // if no,
           // add a comma to the output buffer if necessary:
           if (container->pos) luaL_addchar(&buf, ',');
+          // push current string key on top of stack:
+          key = &container->keys[container->pos];
+          lua_pushlstring(L, key->data, key->length);
           // set containerkey variable to true:
           containerkey = 1;
         } else {
@@ -1328,6 +1328,9 @@
           luaL_addchar(&buf, ':');
           // add a space to the output buffer for pretty results:
           if (pretty) luaL_addchar(&buf, ' ');
+          // push current string key on top of stack:
+          key = &container->keys[container->pos];
+          lua_pushlstring(L, key->data, key->length);
           // replace string key on top of stack with corresponding value:
           lua_rawget(L, json_export_luacontainer_idx);
           // reset containerkey variable