From 5b6b2f98b7981d7b3ed05115f53a44c0fcfd750d Mon Sep 17 00:00:00 2001
From: philip <philip@gladstonefamily.net>
Date: Sun, 20 Sep 2020 10:57:09 -0400
Subject: [PATCH] Make round tripping work for lua53 and floats

---
 app/modules/node.c  | 24 ++++++++++++++++++++++++
 app/modules/sjson.c | 13 +++++++++----
 2 files changed, 33 insertions(+), 4 deletions(-)

diff --git a/app/modules/node.c b/app/modules/node.c
index 47e162c3..6567ef89 100644
--- a/app/modules/node.c
+++ b/app/modules/node.c
@@ -643,6 +643,28 @@ static int node_writercr (lua_State *L) {
   lua_pushinteger(L, n);
   return 1;
 }
+
+static int node_int2float(lua_State *L) {
+  union {
+    lua_Integer i;
+    lua_Float f;
+  } u;
+
+  u.i = luaL_checkinteger(L, 1);
+  lua_pushnumber(L, u.f);
+  return 1;
+}
+
+static int node_float2int(lua_State *L) {
+  union {
+    lua_Integer i;
+    lua_Float f;
+  } u;
+
+  u.f = luaL_checknumber(L, 1);
+  lua_pushinteger(L, u.i);
+  return 1;
+}
 #endif
 
 // Lua: n = node.LFS.reload(lfsimage)
@@ -915,6 +937,8 @@ LROT_BEGIN(node, NULL, 0)
 #endif
 #ifdef DEVELOPMENT_TOOLS
   LROT_FUNCENTRY( osprint, node_osprint )
+  LROT_FUNCENTRY( int2float, node_int2float )
+  LROT_FUNCENTRY( float2int, node_float2int )
 #endif
   LROT_FUNCENTRY( getpartitiontable, node_getpartitiontable )
   LROT_FUNCENTRY( setpartitiontable, node_setpartitiontable )
diff --git a/app/modules/sjson.c b/app/modules/sjson.c
index 2dc3ca08..8e2b2384 100644
--- a/app/modules/sjson.c
+++ b/app/modules/sjson.c
@@ -18,6 +18,8 @@
 
 #define DBG_PRINTF(...)
 
+#define SJSON_FLOAT_FMT   ((sizeof(lua_Float) == 8) ? "%.19g" : "%.9g")
+
 typedef struct {
   jsonsl_t jsn;
   int result_ref;
@@ -720,10 +722,13 @@ static void encode_lua_object(lua_State *L, ENC_DATA *data, int argno, const cha
     case LUA_TNUMBER:
     {
       lua_pushvalue(L, argno);
-      size_t len;
-      const char *str = lua_tolstring(L, -1, &len);
-      char value[len + 1];
-      strcpy(value, str);
+      char value[50];
+
+      if (lua_isinteger(L, -1)) {
+        l_sprintf(value, sizeof(value), LUA_INTEGER_FMT, lua_tointeger(L, -1));
+      } else {
+        l_sprintf(value, sizeof(value), SJSON_FLOAT_FMT, lua_tonumber(L, -1));
+      }
       lua_pop(L, 1);
       if (strcmp(value, "-Infinity") == 0 || strcmp(value, "NaN") == 0 || strcmp(value, "Infinity") == 0) {
         luaL_addstring(&b, "null");   // According to ECMA-262 section 24.5.2 Note 4