Simple anti-spam mechanism

inc/config.php

@@ -308,9 +308,16 @@
         'json_response',
         'user_flag',
         'no_country',
-        'tag'
+        'tag',
+        'simple_spam'
     );
 
+    // Enable simple anti-spam measure.
+    $config['simple_spam'] = array (
+            'question' => 'What is 2 + 2?',
+            'answer' => '4'
+        );
+
     // Enable reCaptcha to make spam even harder. Rarely necessary.
     $config['recaptcha'] = false;
 

post.php

@@ -483,6 +483,12 @@ function handle_post(){
             }
         }
 
+        if ($config['simple_spam'] && $post['op']) {
+            if(!isset($_POST['simple_spam']) || $config['simple_spam']['answer'] != $_POST['simple_spam'])){
+                $config['error']['spam'];
+            }
+        }
+
         if(isset($config['securimage']) && $config['securimage']){
 
             if(!isset($_POST['captcha'])){

templates/post_form.html

@@ -213,6 +213,16 @@
 				{{ antibot.html() }}
 			</td>
 		</tr>{% endif %}
+		{% if config.simple_anti_spam and not id %}<tr>
+			<th>
+				{{ config.simple_anti_spam.prompt }}
+				{{ antibot.html() }}
+			</th>
+			<td>
+				<input type="text" name="simple_anti_spam_answer" value="" size="12" maxlength="18" autocomplete="off"> 
+				{{ antibot.html() }}
+			</td>
+		</tr>{% endif %}
 	</table>
 {{ antibot.html(true) }}
 <input type="hidden" name="hash" value="{{ antibot.hash() }}">