diff --git a/ext/pdo/pdo_dbh.c b/ext/pdo/pdo_dbh.c
index eb77693f5bf..8917b9b0dc1 100644
--- a/ext/pdo/pdo_dbh.c
+++ b/ext/pdo/pdo_dbh.c
@@ -814,9 +814,7 @@ static zend_result pdo_dbh_attribute_set(pdo_dbh_t *dbh, zend_long attr, zval *v
 	}
 
 fail:
-	if (attr == PDO_ATTR_AUTOCOMMIT) {
-		zend_throw_exception_ex(php_pdo_get_exception(), 0, "The auto-commit mode cannot be changed for this driver");
-	} else if (!dbh->methods->set_attribute) {
+	if (!dbh->methods->set_attribute) {
 		pdo_raise_impl_error(dbh, NULL, "IM001", "driver does not support setting attributes");
 	} else {
 		PDO_HANDLE_DBH_ERR();
diff --git a/ext/pdo_mysql/mysql_driver.c b/ext/pdo_mysql/mysql_driver.c
index a666489a503..641a9add1ae 100644
--- a/ext/pdo_mysql/mysql_driver.c
+++ b/ext/pdo_mysql/mysql_driver.c
@@ -349,7 +349,11 @@ static int mysql_handle_commit(pdo_dbh_t *dbh)
 {
 	PDO_DBG_ENTER("mysql_handle_commit");
 	PDO_DBG_INF_FMT("dbh=%p", dbh);
-	PDO_DBG_RETURN(0 == mysql_commit(((pdo_mysql_db_handle *)dbh->driver_data)->server));
+	if (mysql_commit(((pdo_mysql_db_handle *)dbh->driver_data)->server)) {
+		pdo_mysql_error(dbh);
+		PDO_DBG_RETURN(0);
+	}
+	PDO_DBG_RETURN(1);
 }
 /* }}} */
 
@@ -358,7 +362,11 @@ static int mysql_handle_rollback(pdo_dbh_t *dbh)
 {
 	PDO_DBG_ENTER("mysql_handle_rollback");
 	PDO_DBG_INF_FMT("dbh=%p", dbh);
-	PDO_DBG_RETURN(0 == mysql_rollback(((pdo_mysql_db_handle *)dbh->driver_data)->server));
+	if (mysql_rollback(((pdo_mysql_db_handle *)dbh->driver_data)->server)) {
+		pdo_mysql_error(dbh);
+		PDO_DBG_RETURN(0);
+	}
+	PDO_DBG_RETURN(1);
 }
 /* }}} */
 
@@ -368,7 +376,11 @@ static inline int mysql_handle_autocommit(pdo_dbh_t *dbh)
 	PDO_DBG_ENTER("mysql_handle_autocommit");
 	PDO_DBG_INF_FMT("dbh=%p", dbh);
 	PDO_DBG_INF_FMT("dbh->autocommit=%d", dbh->auto_commit);
-	PDO_DBG_RETURN(0 == mysql_autocommit(((pdo_mysql_db_handle *)dbh->driver_data)->server, dbh->auto_commit));
+	if (mysql_autocommit(((pdo_mysql_db_handle *)dbh->driver_data)->server, dbh->auto_commit)) {
+		pdo_mysql_error(dbh);
+		PDO_DBG_RETURN(0);
+	}
+	PDO_DBG_RETURN(1);
 }
 /* }}} */
 
@@ -385,7 +397,9 @@ static int pdo_mysql_set_attribute(pdo_dbh_t *dbh, zend_long attr, zval *val)
 			/* ignore if the new value equals the old one */
 			if (dbh->auto_commit ^ bval) {
 				dbh->auto_commit = bval;
-				mysql_handle_autocommit(dbh);
+				if (!mysql_handle_autocommit(dbh)) {
+					PDO_DBG_RETURN(0);
+				}
 			}
 			PDO_DBG_RETURN(1);
 
diff --git a/ext/pdo_mysql/tests/bug66528.phpt b/ext/pdo_mysql/tests/bug66528.phpt
new file mode 100644
index 00000000000..a5c79c12b32
--- /dev/null
+++ b/ext/pdo_mysql/tests/bug66528.phpt
@@ -0,0 +1,51 @@
+--TEST--
+Bug #66528: No PDOException or errorCode if database becomes unavailable before PDO::commit
+--SKIPIF--
+<?php
+if (!extension_loaded('pdo') || !extension_loaded('pdo_mysql')) die('skip not loaded');
+require_once(__DIR__ . DIRECTORY_SEPARATOR . 'skipif.inc');
+require_once(__DIR__ . DIRECTORY_SEPARATOR . 'mysql_pdo_test.inc');
+MySQLPDOTest::skip();
+?>
+--FILE--
+<?php
+require_once(__DIR__ . DIRECTORY_SEPARATOR . 'mysql_pdo_test.inc');
+
+$dbh = MySQLPDOTest::factory();
+$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+$dbh->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, false);
+
+$dbh->exec('DROP TABLE IF EXISTS test');
+$dbh->exec('CREATE TABLE test (a int) engine=innodb');
+$dbh->beginTransaction();
+$dbh->exec('INSERT INTO test (a) VALUES (1), (2)');
+$stmt = $dbh->query('SELECT * FROM test');
+
+try {
+	$dbh->commit();
+} catch (PDOException $e) {
+	echo $e->getMessage(), "\n";
+}
+
+try {
+	$dbh->rollBack();
+} catch (PDOException $e) {
+	echo $e->getMessage(), "\n";
+}
+
+try {
+    $dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+} catch (PDOException $e) {
+	echo $e->getMessage(), "\n";
+}
+
+?>
+--CLEAN--
+<?php
+require __DIR__ . '/mysql_pdo_test.inc';
+MySQLPDOTest::dropTestTable();
+?>
+--EXPECT--
+SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active.  Consider using PDOStatement::fetchAll().  Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.
+SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active.  Consider using PDOStatement::fetchAll().  Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.
+SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active.  Consider using PDOStatement::fetchAll().  Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.