[Minor] Distinguish absent IP address in a more sane way

src/lua/lua_task.c

@@ -3843,7 +3843,12 @@ lua_task_get_from_ip (lua_State *L)
 	struct rspamd_task *task = lua_check_task (L, 1);
 
 	if (task) {
-		rspamd_lua_ip_push (L, task->from_addr);
+		if (task->from_addr) {
+			rspamd_lua_ip_push (L, task->from_addr);
+		}
+		else {
+			lua_pushnil (L);
+		}
 	}
 	else {
 		return luaL_error (L, "invalid arguments");
@@ -3901,7 +3906,12 @@ lua_task_get_client_ip (lua_State *L)
 	struct rspamd_task *task = lua_check_task (L, 1);
 
 	if (task) {
-		rspamd_lua_ip_push (L, task->client_addr);
+		if (task->client_addr) {
+			rspamd_lua_ip_push (L, task->client_addr);
+		}
+		else {
+			lua_pushnil (L);
+		}
 	}
 	else {
 		return luaL_error (L, "invalid arguments");

src/plugins/lua/dmarc.lua

@@ -181,7 +181,7 @@ local dmarc_grammar = gen_dmarc_grammar()
 local function dmarc_report(task, spf_ok, dkim_ok, disposition,
     sampled_out, hfromdom, spfdom, dres, spf_result)
   local ip = task:get_from_ip()
-  if not ip:is_valid() then
+  if ip and not ip:is_valid() then
     return nil
   end
   local rspamd_lua_utils = require "lua_util"

src/plugins/lua/rbl.lua

@@ -391,7 +391,7 @@ local function gen_rbl_callback(rule)
   local function check_local(task, _)
     local ip = task:get_from_ip()
 
-    if not ip:is_valid() then
+    if ip and not ip:is_valid() then
       ip = nil
     end
 

src/plugins/lua/settings.lua

@@ -552,7 +552,7 @@ local function process_settings_table(tbl, allow_ids, mempool)
           check = gen_check_closure(convert_to_table(elt.ip, ips_table), check_ip_setting),
           extract = function(task)
             local ip = task:get_from_ip()
-            if ip:is_valid() then return ip end
+            if ip and ip:is_valid() then return ip end
             return nil
           end,
         }