Merge pull request #27621 from dylanahsmith/mysql2-nil-connection-test

activerecord/test: Fix Mysql2ConnectionTest#test_execute_after_disconnect

activerecord/test/cases/adapters/mysql2/connection_test.rb

@@ -66,9 +66,10 @@ def test_successful_reconnection_after_timeout_with_verify
   def test_execute_after_disconnect
     @connection.disconnect!
 
-    assert_raise(ActiveRecord::StatementInvalid) do
+    error = assert_raise(ActiveRecord::StatementInvalid) do
       @connection.execute("SELECT 1")
     end
+    assert_kind_of Mysql2::Error, error.cause
   end
 
   def test_quote_after_disconnect