FIX Ensure primary connection is updated with temporary database

_config.php

@@ -12,7 +12,7 @@
  */
 if (class_exists('Resque_Event') && class_exists('SSResqueRun')) {
  Resque_Event::listen('beforeFork', function ($data) {
- $databaseConfig = DB::getConfig();
+ $databaseConfig = DB::getConfig(DB::CONN_PRIMARY);
 
  // Reconnect to the database - this may connect to the old DB first, but is required because these processes
  // are long-lived, and MySQL connections often get closed in between worker runs. We need to connect before

src/TestSessionEnvironment.php

@@ -272,7 +272,7 @@ public function applyState($state)
  $this->extend('onBeforeApplyState', $state);
 
  // back up source
- $databaseConfig = DB::getConfig();
+ $databaseConfig = DB::getConfig(DB::CONN_PRIMARY);
  $this->oldDatabaseName = $databaseConfig['database'];
 
  // Load existing state from $this->state into $state, if there is any
@@ -523,9 +523,9 @@ public function loadFixtureIntoDb($fixtureFile)
  public function resetDatabaseName()
  {
  if ($this->oldDatabaseName) {
- $databaseConfig = DB::getConfig();
+ $databaseConfig = DB::getConfig(DB::CONN_PRIMARY);
  $databaseConfig['database'] = $this->oldDatabaseName;
- DB::setConfig($databaseConfig);
+ DB::setConfig($databaseConfig, DB::CONN_PRIMARY);
 
  $conn = DB::get_conn();
 
@@ -568,7 +568,7 @@ public function connectToDatabase($state = null)
  $state = $this->getState();
  }
 
- $databaseConfig = DB::getConfig();
+ $databaseConfig = DB::getConfig(DB::CONN_PRIMARY);
 
  if (isset($state->database) && $state->database) {
  if (!DB::get_conn()) {
@@ -579,14 +579,14 @@ public function connectToDatabase($state = null)
  }
 
  // Connect to database
- DB::connect($databaseConfig);
+ $this->connectToDB($databaseConfig);
  } else {
  // We've already connected to the database, do a fast check to see what database we're currently using
  $db = DB::get_conn()->getSelectedDatabase();
  if (isset($state->database) && $db != $state->database) {
  $this->oldDatabaseName = $databaseConfig['database'];
  $databaseConfig['database'] = $state->database;
- DB::connect($databaseConfig);
+ $this->connectToDB($databaseConfig);
  }
  }
  }
@@ -622,4 +622,17 @@ public function waitForPendingRequests($await = 700, $timeout = 10000)
 
  return true;
  }
+
+ private function connectToDB(array $databaseConfig): void
+ {
+ if (method_exists(DB::class, 'hasConfig')) {
+ // CMS 5.4+ - ensure we connect the primary connection and not a replica
+ // which can happen if we use the default value of DB::CONN_DYNAMIC
+ // and there is a replica database configured
+ DB::connect($databaseConfig, DB::CONN_PRIMARY);
+ } else {
+ // CMS 5.3 and below do not support replica connections, use 'default' connection
+ DB::connect($databaseConfig);
+ }
+ }
 }