From 4427dda116d81ef0d041c4b258432da824ad3685 Mon Sep 17 00:00:00 2001
From: Francois Perrad <francois.perrad@gadz.org>
Date: Sat, 25 Mar 2017 12:07:16 +0100
Subject: [PATCH] backport math.tointeger from 5.3

---
 src/lib_math.c | 13 +++++++++++++
 src/lj_api.c   | 40 +++++++++++++++++++++++++++++++++-------
 src/lua.h      |  2 ++
 3 files changed, 48 insertions(+), 7 deletions(-)

diff --git a/src/lib_math.c b/src/lib_math.c
index 073a628a..e35e1c49 100644
--- a/src/lib_math.c
+++ b/src/lib_math.c
@@ -94,6 +94,19 @@ LJLIB_ASM(math_min)		LJLIB_REC(math_minmax IR_MIN)
 }
 LJLIB_ASM_(math_max)		LJLIB_REC(math_minmax IR_MAX)
 
+LJLIB_CF(math_tointeger)
+{
+  int valid;
+  lua_Integer n = lua_tointegerx(L, 1, &valid);
+  if (valid)
+    lua_pushinteger(L, n);
+  else {
+    luaL_checkany(L, 1);
+    lua_pushnil(L);  /* value is not convertible to integer */
+  }
+  return 1;
+}
+
 LJLIB_CF(math_type)
 {
   if (lua_type(L, 1) == LUA_TNUMBER) {
diff --git a/src/lj_api.c b/src/lj_api.c
index f1c704da..802e76a8 100644
--- a/src/lj_api.c
+++ b/src/lj_api.c
@@ -319,16 +319,25 @@ LUA_API int lua_lessthan(lua_State *L, int idx1, int idx2)
   }
 }
 
-LUA_API lua_Number lua_tonumber(lua_State *L, int idx)
+LUA_API lua_Number lua_tonumberx (lua_State *L, int idx, int *pisnum)
 {
   cTValue *o = index2adr(L, idx);
   TValue tmp;
-  if (LJ_LIKELY(tvisnumber(o)))
+  if (LJ_LIKELY(tvisnumber(o))) {
+    if (pisnum) *pisnum = 1;
     return numberVnum(o);
-  else if (tvisstr(o) && lj_strscan_num(strV(o), &tmp))
+  } else if (tvisstr(o) && lj_strscan_num(strV(o), &tmp)) {
+    if (pisnum) *pisnum = 1;
     return numV(&tmp);
-  else
+  } else {
+    if (pisnum) *pisnum = 0;
     return 0;
+  }
+}
+
+LUA_API lua_Number lua_tonumber(lua_State *L, int idx)
+{
+  return lua_tonumberx(L, idx, NULL);
 }
 
 LUALIB_API lua_Number luaL_checknumber(lua_State *L, int idx)
@@ -355,22 +364,34 @@ LUALIB_API lua_Number luaL_optnumber(lua_State *L, int idx, lua_Number def)
   return numV(&tmp);
 }
 
-LUA_API lua_Integer lua_tointeger(lua_State *L, int idx)
+LUA_API lua_Integer lua_tointegerx (lua_State *L, int idx, int *pisnum)
 {
   cTValue *o = index2adr(L, idx);
   TValue tmp;
   lua_Number n;
   if (LJ_LIKELY(tvisint(o))) {
+    if (pisnum) *pisnum = 1;
     return intV(o);
   } else if (LJ_LIKELY(tvisnum(o))) {
     n = numV(o);
   } else {
-    if (!(tvisstr(o) && lj_strscan_number(strV(o), &tmp)))
+    if (!(tvisstr(o) && lj_strscan_number(strV(o), &tmp))) {
+      if (pisnum) *pisnum = 0;
       return 0;
-    if (tvisint(&tmp))
+    }
+    if (tvisint(&tmp)) {
+      if (pisnum) *pisnum = 1;
       return (lua_Integer)intV(&tmp);
+    }
     n = numV(&tmp);
   }
+#if LJ52
+  if ((lua_Number)(lua_Integer)n != n) {
+    if (pisnum) *pisnum = 0;
+    return 0;
+  }
+#endif
+  if (pisnum) *pisnum = 1;
 #if LJ_64
   return (lua_Integer)n;
 #else
@@ -378,6 +399,11 @@ LUA_API lua_Integer lua_tointeger(lua_State *L, int idx)
 #endif
 }
 
+LUA_API lua_Integer lua_tointeger(lua_State *L, int idx)
+{
+  return lua_tointegerx(L, idx, NULL);
+}
+
 LUALIB_API lua_Integer luaL_checkinteger(lua_State *L, int idx)
 {
   cTValue *o = index2adr(L, idx);
diff --git a/src/lua.h b/src/lua.h
index bee120ef..31571252 100644
--- a/src/lua.h
+++ b/src/lua.h
@@ -347,6 +347,8 @@ LUA_API void *lua_upvalueid (lua_State *L, int idx, int n);
 LUA_API void lua_upvaluejoin (lua_State *L, int idx1, int n1, int idx2, int n2);
 LUA_API int lua_loadx (lua_State *L, lua_Reader reader, void *dt,
 		       const char *chunkname, const char *mode);
+LUA_API lua_Number lua_tonumberx (lua_State *L, int idx, int *isnum);
+LUA_API lua_Integer lua_tointegerx (lua_State *L, int idx, int *isnum);
 /* From Lua 5.3. */
 LUA_API int lua_isinteger (lua_State *L, int idx);