Fixes for compiling with a newer (system) jsoncpp (#4429)

* Move included json code to jsoncpp subdirectory

This is needed to avoid having to specify the minetest src directory
as a system include when fixing the json includes.

* Fix json includes

They used "", so that the compiler searches the project's directory
first. The result was that when compiling with a system jsoncpp,
the project's own version of json.h was still included, instead of
the system version.

The includes now use <>, so a system location, or one specified with
'-Ilocation' is searched only.

* Fix for jsoncpp deprecated function warning

When compiling with a newer version of jsoncpp (and
ENABLE_SYSTEM_JSONCPP=true), jsoncpp emits a warning
about a deprecated function that minetest uses.

10 files changed, 11 insertions, 6 deletions

diff --git a/src/convert_json.h b/src/convert_json.h
index 6732fcfa3..55321af5f 100644
--- a/src/convert_json.h
+++ b/src/convert_json.h
@@ -20,7 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #ifndef __CONVERT_JSON_H__
 #define __CONVERT_JSON_H__
 
-#include "json/json.h"
+#include <json/json.h>
 
 struct ModStoreMod;
 struct ModStoreModDetails;
diff --git a/src/json/CMakeLists.txt b/src/jsoncpp/json/CMakeLists.txt
index 9056e4b6d..9056e4b6d 100644
--- a/src/json/CMakeLists.txt
+++ b/src/jsoncpp/json/CMakeLists.txt
diff --git a/src/json/UPDATING b/src/jsoncpp/json/UPDATING
index d00076601..d00076601 100644
--- a/src/json/UPDATING
+++ b/src/jsoncpp/json/UPDATING
diff --git a/src/json/json.h b/src/jsoncpp/json/json.h
index 396aafa82..396aafa82 100644
--- a/src/json/json.h
+++ b/src/jsoncpp/json/json.h
diff --git a/src/json/jsoncpp.cpp b/src/jsoncpp/json/jsoncpp.cpp
index 7a04736de..7a04736de 100644
--- a/src/json/jsoncpp.cpp
+++ b/src/jsoncpp/json/jsoncpp.cpp
diff --git a/src/mods.h b/src/mods.h
index 12576516d..af7777d18 100644
--- a/src/mods.h
+++ b/src/mods.h
@@ -26,7 +26,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <vector>
 #include <string>
 #include <map>
-#include "json/json.h"
+#include <json/json.h>
 #include "config.h"
 
 #define MODNAME_ALLOWED_CHARS "abcdefghijklmnopqrstuvwxyz0123456789_"
diff --git a/src/script/common/c_content.cpp b/src/script/common/c_content.cpp
index 06e20c2a0..c664101ea 100644
--- a/src/script/common/c_content.cpp
+++ b/src/script/common/c_content.cpp
@@ -33,7 +33,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "porting.h"
 #include "mg_schematic.h"
 #include "noise.h"
-#include "json/json.h"
+#include <json/json.h>
 
 struct EnumString es_TileAnimationType[] =
 {
@@ -1250,8 +1250,13 @@ static bool push_json_value_helper(lua_State *L, const Json::Value &value,
 			lua_newtable(L);
 			for (Json::Value::const_iterator it = value.begin();
 					it != value.end(); ++it) {
+#ifndef JSONCPP_STRING
 				const char *str = it.memberName();
 				lua_pushstring(L, str ? str : "");
+#else
+				std::string str = it.name();
+				lua_pushstring(L, str.c_str());
+#endif
 				push_json_value_helper(L, *it, nullindex);
 				lua_rawset(L, -3);
 			}
diff --git a/src/script/lua_api/l_util.cpp b/src/script/lua_api/l_util.cpp
index 95a5fc4d1..13c0d702f 100644
--- a/src/script/lua_api/l_util.cpp
+++ b/src/script/lua_api/l_util.cpp
@@ -23,7 +23,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "common/c_content.h"
 #include "cpp_api/s_async.h"
 #include "serialization.h"
-#include "json/json.h"
+#include <json/json.h>
 #include "cpp_api/s_security.h"
 #include "porting.h"
 #include "debug.h"
diff --git a/src/serverlist.cpp b/src/serverlist.cpp
index de7962a68..87ca5dc04 100644
--- a/src/serverlist.cpp
+++ b/src/serverlist.cpp
@@ -29,7 +29,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "porting.h"
 #include "log.h"
 #include "network/networkprotocol.h"
-#include "json/json.h"
+#include <json/json.h>
 #include "convert_json.h"
 #include "httpfetch.h"
 #include "util/string.h"
diff --git a/src/serverlist.h b/src/serverlist.h
index 8ffea44cc..0747c3920 100644
--- a/src/serverlist.h
+++ b/src/serverlist.h
@@ -20,7 +20,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include <iostream>
 #include "config.h"
 #include "mods.h"
-#include "json/json.h"
+#include <json/json.h>
 
 #ifndef SERVERLIST_HEADER
 #define SERVERLIST_HEADER