bugfix: access nonexistent fields in the "ngx" table in init_by_lua* …

…could lead to the exception "no request object found" because of the overreacting __index metamethod of the "ngx" table.

src/ngx_http_lua_misc.c

@@ -44,12 +44,14 @@ ngx_http_lua_ngx_get(lua_State *L)
 
     r = ngx_http_lua_get_req(L);
     if (r == NULL) {
-        return luaL_error(L, "no request object found");
+        lua_pushnil(L);
+        return 1;
     }
 
     ctx = ngx_http_get_module_ctx(r, ngx_http_lua_module);
     if (ctx == NULL) {
-        return luaL_error(L, "no request ctx found");
+        lua_pushnil(L);
+        return 1;
     }
 
     p = (u_char *) luaL_checklstring(L, -1, &len);

t/086-init-by.t

@@ -9,7 +9,7 @@ use Test::Nginx::Socket::Lua;
 
 repeat_each(2);
 
-plan tests => repeat_each() * (blocks() * 3 + 2);
+plan tests => repeat_each() * (blocks() * 3 + 3);
 
 #no_diff();
 #no_long_string();
@@ -278,3 +278,30 @@ baz = 78
 [error]
 Failed to resume our co: 
 
+
+
+=== TEST 11: access a field in the ngx. table
+--- http_config
+    init_by_lua '
+        print("INIT 1: foo = ", ngx.foo)
+        ngx.foo = 3
+        print("INIT 2: foo = ", ngx.foo)
+    ';
+--- config
+    location /t {
+        echo ok;
+    }
+--- request
+GET /t
+--- response_body
+ok
+--- no_error_log
+[error]
+--- grep_error_log eval: qr/INIT \d+: foo = \S+/
+--- grep_error_log_out eval
+[
+"INIT 1: foo = nil
+INIT 2: foo = 3
+",
+"",
+]