Backport of Lua exhancements from trunk, mostly to support 5.3

Changes with Apache 2.4.26

  *) mod_lua: Support for Lua 5.3

  *) mod_proxy_http2: support for ProxyPreserverHost directive. [Stefan Eissing]

  *) mod_http2: fix for crash when running out of memory.

#

XDEFINES	+= \

			-DLUA_COMPAT_ALL \

			-DLUA_COMPAT_5_2 \

			-DLUA_COMPAT_5_1 \

			-DLUA_COMPAT_MODULE \

			$(EOLIST)

#

-*- mode:org -*-

* Requirements:

** lua 5.1 ( http://www.lua.org/ )

** Apache HTTPD 2.2 ( http://httpd.apache.org/ ) or Apache HTTPD 2.3

** lua 5.1, 5.2, 5.3 ( http://www.lua.org/ ) or LuaJIT 2.x ( http://www.luajit.org/ )

** Apache HTTPD 2.4 ( http://httpd.apache.org/ ) or higher

* Documentation

  See docs/README

* Building

  For now, see docs/building-from-subversion.txt

* To Consider

  Allow definition of lua_State instances associated with arbitrary

  pool using the pool's user_data constuct. There would, here, be two

  types, pooled and singleton. On the other hand, singleton would work

  fine for almost all cases -- the exception being a process or server

  pool, and then we could stay singleton anyway and lock around it.

  The current "server scope" behavior could, instead, fall into

  connection scope, for long-lived connections, really we want thread

  scope (which Brian Akins knows how to do). Is there a pool

  associated with a thread? Contention on the pool is a pain in a

  highly concurrent environment.

  Could use apr_thread_data_(get|set) if I can find a way to hook into

  thread destruction. Looks like apr threads let you use the standard

  APR_POOL_DECLARE_ACCESSOR(thread); defined method, just need to look

  up what form that takes. -- apr_thread_pool_get -- just attach to

  that pool.

  Given that, we can associate a hash of lua_State instances with

  arbitrary pools, such as the request pool, thread pool, server pool,

  etc. We then use the file as key into the hash. Users, able to

  specify the handler function, can then make use of the same file

  with different handlers to reuse states.

* Task List

** TODO Use r->file to determine file, doing rewriting in translate_name   

   it is pre-handler, will prolly be on the request_config somewhere,

   but sometimes cannot put there, so... fun

** TODO Mapping in the server_rec

** TODO Connection scoped vms

** TODO Figure out how reentrancy works regarding filter chain stuff. 

   Do we need new "threads"?

** TODO Flesh out apw_*getvm for each flavor we allow

** TODO Rework apw_sgetvm to use the create_vm stuff like apw_rgetvm

** TODO apw_rgetvm needs to handle connection scoped vms     

** TODO provide means to implement authn and authz providers

** TODO: Flatten LuaHook* to LuaHook phase file fn ?

** TODO: document or remove block sections

** TODO: test per-dir behavior of block sections

** Stefan Fritsch

** Eric Covener

** Daniel Gruno

** Günter Knauf

** Jim Jagielski

    lua_getinfo(L, "Sl", &dbg);

    msg = luaL_checkstring(L, 2);

    /* Intentional no APLOGNO */

    ap_log_error(dbg.source, dbg.currentline, APLOG_MODULE_INDEX, level, 0,

                 cmd->server, "%s", msg);

    return 0;

                arguments = lua_tostring(L, 3);

                lua_settop(L, 0);

                if (strlen(arguments)) {

                if (*arguments) {

                    rc = apr_dbd_open_ex(dbdhandle->driver, pool, 

                            arguments, &dbdhandle->handle, &error);

                    if (rc == APR_SUCCESS) {