synchronized with lua-nginx-module #33a5517 (fixed clang warnings).

Upstream patch from agentzh.

Author: thibaultcha

src/subsys/ngx_subsys_lua_semaphore.c.tt2

@@ -88,6 +88,8 @@ ngx_[% subsys %]_lua_alloc_sema(void)
     lmcf = ngx_[% subsys %]_cycle_get_module_main_conf(ngx_cycle,
                                                        ngx_[% subsys %]_lua_module);
 
+    ngx_[% subsys %]_lua_assert(lmcf != NULL);
+
     mm = lmcf->sema_mm;
 
     if (!ngx_queue_empty(&mm->free_queue)) {
@@ -174,6 +176,8 @@ ngx_[% subsys %]_lua_sema_mm_cleanup(void *data)
         sem = ngx_queue_data(q, ngx_[% subsys %]_lua_sema_t, chain);
         block = sem->block;
 
+        ngx_[% subsys %]_lua_assert(block != NULL);
+
         if (block->used == 0) {
             iter = (ngx_[% subsys %]_lua_sema_t *) (block + 1);
 

src/subsys/ngx_subsys_lua_util.c.tt2

@@ -277,7 +277,6 @@ ngx_[% subsys %]_lua_new_state(lua_State *parent_vm, ngx_cycle_t *cycle,
 
         lua_pushliteral(L, LUA_DEFAULT_PATH ";"); /* package default */
         lua_getfield(L, -2, "path"); /* package default old */
-        old_path = lua_tolstring(L, -1, &old_path_len);
         lua_concat(L, 2); /* package new */
         lua_setfield(L, -2, "path"); /* package */
 #endif