From ddf0d9604f6aaca33e31e646db66a232984e32b1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Maur=C3=ADcio=20Meneghini=20Fauth?= <mauricio@fauth.dev>
Date: Sat, 12 Feb 2022 15:52:27 -0300
Subject: [PATCH] Clear config storage params from session after failed access
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Signed-off-by: Maurício Meneghini Fauth <mauricio@fauth.dev>
---
 libraries/classes/UserPreferences.php | 29 +++++++++++++++++++++------
 test/classes/UserPreferencesTest.php  |  4 +++-
 2 files changed, 26 insertions(+), 7 deletions(-)

diff --git a/libraries/classes/UserPreferences.php b/libraries/classes/UserPreferences.php
index 4e7ddfe4ca..b7113a457a 100644
--- a/libraries/classes/UserPreferences.php
+++ b/libraries/classes/UserPreferences.php
@@ -9,6 +9,7 @@ use PhpMyAdmin\Config\Forms\User\UserFormList;
 use function array_flip;
 use function array_merge;
 use function basename;
+use function htmlspecialchars;
 use function http_build_query;
 use function is_array;
 use function json_decode;
@@ -166,12 +167,17 @@ class UserPreferences
         }
         if (! $dbi->tryQuery($query, DatabaseInterface::CONNECT_CONTROL)) {
             $message = Message::error(__('Could not save configuration'));
-            $message->addMessage(
-                Message::rawError(
-                    $dbi->getError(DatabaseInterface::CONNECT_CONTROL)
-                ),
-                '<br><br>'
-            );
+            $message->addMessage(Message::error($dbi->getError(DatabaseInterface::CONNECT_CONTROL)), '<br><br>');
+            if (! $this->hasAccessToDatabase($cfgRelation['db'])) {
+                /**
+                 * When phpMyAdmin cached the configuration storage parameters, it checked if the database can be
+                 * accessed, so if it could not be accessed anymore, then the cache must be cleared as it's out of date.
+                 */
+                $_SESSION['relation'][$GLOBALS['server']] = [];
+                $message->addMessage(Message::error(htmlspecialchars(
+                    __('The phpMyAdmin configuration storage database could not be accessed.')
+                )), '<br><br>');
+            }
 
             return $message;
         }
@@ -179,6 +185,17 @@ class UserPreferences
         return true;
     }
 
+    private function hasAccessToDatabase(string $database): bool
+    {
+        $escapedDb = $GLOBALS['dbi']->escapeString($database);
+        $query = 'SELECT SCHEMA_NAME FROM INFORMATION_SCHEMA.SCHEMATA WHERE SCHEMA_NAME = \'' . $escapedDb . '\';';
+        if ($GLOBALS['cfg']['Server']['DisableIS']) {
+            $query = 'SHOW DATABASES LIKE \'' . Util::escapeMysqlWildcards($escapedDb) . '\';';
+        }
+
+        return (bool) $GLOBALS['dbi']->fetchSingleRow($query, 'ASSOC', DatabaseInterface::CONNECT_CONTROL);
+    }
+
     /**
      * Returns a user preferences array filtered by $cfg['UserprefsDisallow']
      * (exclude list) and keys from user preferences form (allow list)
diff --git a/test/classes/UserPreferencesTest.php b/test/classes/UserPreferencesTest.php
index 13a5d47f9f..3020e4ddaf 100644
--- a/test/classes/UserPreferencesTest.php
+++ b/test/classes/UserPreferencesTest.php
@@ -140,6 +140,7 @@ class UserPreferencesTest extends AbstractNetworkTestCase
      */
     public function testSave(): void
     {
+        $GLOBALS['cfg']['Server']['DisableIS'] = true;
         $GLOBALS['server'] = 2;
         $_SESSION['relation'][2]['PMA_VERSION'] = PMA_VERSION;
         $_SESSION['relation'][2]['userconfigwork'] = null;
@@ -251,7 +252,8 @@ class UserPreferencesTest extends AbstractNetworkTestCase
 
         $this->assertInstanceOf(Message::class, $result);
         $this->assertEquals(
-            'Could not save configuration<br><br>err1',
+            'Could not save configuration<br><br>err1'
+            . '<br><br>The phpMyAdmin configuration storage database could not be accessed.',
             $result->getMessage()
         );
     }