Catch a DB connection exception earlier [MAILPOET-966]

lib/Config/Database.php

@@ -42,9 +42,17 @@ class Database {
       $driver_options[] = $character_set;
     }
 
+    /**
+     * Rethrow PDOExceptions to prevent exposing sensitive data in stack traces
+     */
+    try {
       $current_options = ORM::for_table("")
         ->raw_query('SELECT @@session.wait_timeout as wait_timeout')
         ->findOne();
+    } catch (\PDOException $e) {
+      throw new \Exception($e->getMessage());
+    }
+
     if($current_options && (int)$current_options->wait_timeout < $this->driver_option_wait_timeout) {
       $driver_options[] = 'SESSION wait_timeout = ' . $this->driver_option_wait_timeout;
     }

lib/Config/Initializer.php

@@ -31,7 +31,12 @@ class Initializer {
       return;
     }
 
+    try {
       $this->setupDB();
+    } catch(\Exception $e) {
+      $this->handleFailedInitialization($e);
+      return;
+    }
 
     // activation function
     register_activation_hook(
@@ -232,7 +237,10 @@ class Initializer {
   }
 
   function handleFailedInitialization($message) {
+    // Check if we are able to add pages at this point
+    if (function_exists('wp_get_current_user')) {
       Menu::addErrorPage();
+    }
     return WPNotice::displayError($message);
   }
 }