From 3b06f983ae0e57b90cdeb500c84bb524e5c3635b Mon Sep 17 00:00:00 2001
From: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 11 Dec 2018 11:54:14 -0200
Subject: [PATCH] Details

- in 'luaB_tonumber', do not need to "checkany" when argument
is a number.

- in 'lua_resume', the call to 'luaD_rawrunprotected' cannot return
a status equal to -1.
---
 lbaselib.c |  2 +-
 ldo.c      | 29 +++++++++++++----------------
 2 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/lbaselib.c b/lbaselib.c
index 201c93e3..7c0ebfec 100644
--- a/lbaselib.c
+++ b/lbaselib.c
@@ -68,7 +68,6 @@ static const char *b_str2int (const char *s, int base, lua_Integer *pn) {
 
 static int luaB_tonumber (lua_State *L) {
   if (lua_isnoneornil(L, 2)) {  /* standard conversion? */
-    luaL_checkany(L, 1);
     if (lua_type(L, 1) == LUA_TNUMBER) {  /* already a number? */
       lua_settop(L, 1);  /* yes; return it */
       return 1;
@@ -79,6 +78,7 @@ static int luaB_tonumber (lua_State *L) {
       if (s != NULL && lua_stringtonumber(L, s) == l + 1)
         return 1;  /* successful conversion to number */
       /* else not a number */
+      luaL_checkany(L, 1);  /* (but there must be some parameter) */
     }
   }
   else {
diff --git a/ldo.c b/ldo.c
index 2762fefa..bdd7fb6d 100644
--- a/ldo.c
+++ b/ldo.c
@@ -678,22 +678,19 @@ LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
   L->nny = 0;  /* allow yields */
   api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs);
   status = luaD_rawrunprotected(L, resume, &nargs);
-  if (unlikely(status == -1))  /* error calling 'lua_resume'? */
-    status = LUA_ERRRUN;
-  else {  /* continue running after recoverable errors */
-    while (errorstatus(status) && recover(L, status)) {
-      /* unroll continuation */
-      status = luaD_rawrunprotected(L, unroll, &status);
-    }
-    if (likely(!errorstatus(status)))
-      lua_assert(status == L->status);  /* normal end or yield */
-    else {  /* unrecoverable error */
-      status = luaF_close(L, L->stack, status);  /* close all upvalues */
-      L->status = cast_byte(status);  /* mark thread as 'dead' */
-      luaD_seterrorobj(L, status, L->stack + 1);  /* push error message */
-      L->ci = &L->base_ci;  /* back to the original C level */
-      L->ci->top = L->top;
-    }
+   /* continue running after recoverable errors */
+  while (errorstatus(status) && recover(L, status)) {
+    /* unroll continuation */
+    status = luaD_rawrunprotected(L, unroll, &status);
+  }
+  if (likely(!errorstatus(status)))
+    lua_assert(status == L->status);  /* normal end or yield */
+  else {  /* unrecoverable error */
+    status = luaF_close(L, L->stack, status);  /* close all upvalues */
+    L->status = cast_byte(status);  /* mark thread as 'dead' */
+    luaD_seterrorobj(L, status, L->stack + 1);  /* push error message */
+    L->ci = &L->base_ci;  /* back to the original C level */
+    L->ci->top = L->top;
   }
   *nresults = (status == LUA_YIELD) ? L->ci->u2.nyield
                                     : cast_int(L->top - (L->ci->func + 1));