fix on_state_create circular logic issue

* if config.on_state_create() is a C function, call it by direct C
closure reconstruction in newly created states
* bumped version to 3.7.6

1 files changed, 43 insertions, 13 deletions

diff --git a/src/tools.c b/src/tools.c
index 60f9012..9f36858 100644
--- a/src/tools.c
+++ b/src/tools.c
@@ -8,7 +8,7 @@
 ===============================================================================
 
 Copyright (C) 2002-10 Asko Kauppi <akauppi@gmail.com>
-              2011-13 benoit Germain <bnt.germain@gmail.com>
+              2011-14 benoit Germain <bnt.germain@gmail.com>
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
@@ -161,6 +161,39 @@ void luaG_dump( lua_State* L ) {
         fprintf( stderr, "\n" );
 }
 
+static lua_CFunction s_on_state_create_func = NULL;
+int initialize_on_state_create( lua_State* L)
+{
+        STACK_CHECK( L);
+        lua_getfield( L, -1, "on_state_create");              // settings on_state_create|nil
+        if( !lua_isnil( L, -1))
+        {
+                // store C function pointer in an internal variable
+                s_on_state_create_func = lua_tocfunction( L, -1);   // settings on_state_create
+                if( s_on_state_create_func != NULL)
+                {
+                        // make sure the function doesn't have upvalues
+                        char const* upname = lua_getupvalue( L, -1, 1);   // settings on_state_create upval?
+                        if( upname != NULL) // should be "" for C functions with upvalues if any
+                        {
+                                luaL_error( L, "on_state_create shouldn't have upvalues");
+                        }
+                        // remove this C function from the config table so that it doesn't cause problems
+                        // when we transfer the config table in newly created Lua states
+                        lua_pushnil( L);                                    // settings on_state_create nil
+                        lua_setfield( L, -3, "on_state_create");            // settings on_state_create
+                }
+                else
+                {
+                        // optim: store marker saying we have such a function in the config table
+                        s_on_state_create_func = initialize_on_state_create;
+                }
+        }
+        lua_pop( L, 1);                                       // settings
+        STACK_END( L, 0);
+        return 0;
+}
+
 // just like lua_xmove, args are (from, to)
 void luaG_copy_one_time_settings( lua_State* L, lua_State* L2, char const* name_)
 {
@@ -569,7 +602,7 @@ void populate_func_lookup_table( lua_State* L, int _i, char const* name_)
 * Base ("unpack", "print" etc.) is always added, unless 'libs' is NULL.
 *
 */
-lua_State* luaG_newstate( lua_State* _from, int const _on_state_create, char const* libs)
+lua_State* luaG_newstate( lua_State* _from, char const* libs)
 {
         // reuse alloc function from the originating state
 #if PROPAGATE_ALLOCF
@@ -587,7 +620,7 @@ lua_State* luaG_newstate( lua_State* _from, int const _on_state_create, char con
         lua_setfield( L, LUA_REGISTRYINDEX, LOOKUP_REGKEY);
 
         // neither libs (not even 'base') nor special init func: we are done
-        if( libs == NULL && _on_state_create <= 0)
+        if( libs == NULL && s_on_state_create_func == NULL)
         {
                 DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "luaG_newstate(NULL)\n" INDENT_END));
                 return L;
@@ -655,22 +688,19 @@ lua_State* luaG_newstate( lua_State* _from, int const _on_state_create, char con
 
         STACK_CHECK( L);
         // call this after the base libraries are loaded and GC is restarted
-        if( _on_state_create > 0)
+        if( s_on_state_create_func != NULL)
         {
                 DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "calling on_state_create()\n" INDENT_END));
-                if( lua_iscfunction( _from, _on_state_create))
+                if( s_on_state_create_func != initialize_on_state_create)
                 {
                         // C function: recreate a closure in the new state, bypassing the lookup scheme
-                        lua_CFunction osc = lua_tocfunction( _from, _on_state_create);
-                        lua_pushcfunction( L, osc);
+                        lua_pushcfunction( L, s_on_state_create_func);
                 }
-                else
+                else // Lua function located in the config table
                 {
-                        STACK_CHECK( _from);
-                        // Lua function: transfer as usual (should work as long as it only uses base libraries)
-                        lua_pushvalue( _from, _on_state_create);
-                        luaG_inter_move( _from, L, 1, eLM_LaneBody);
-                        STACK_END( _from, 0);
+                        lua_getfield( L, LUA_REGISTRYINDEX, CONFIG_REGKEY);
+                        lua_getfield( L, -1, "on_state_create");
+                        lua_remove( L, -2);
                 }
                 // capture error and forward it to main state
                 if( lua_pcall( L, 0, 0, 0) != LUA_OK)