From dfaf7986de0e3f8ae3a310b96213d99a14f34236 Mon Sep 17 00:00:00 2001
From: Saki Takamachi <34942839+SakiTakamachi@users.noreply.github.com>
Date: Mon, 27 Nov 2023 12:38:48 +0900
Subject: [PATCH] [pdo_firebird] Transaction management optimization (#12741)

take2 of #12657

## About Firebird transaction

Firebird is a full transactional database, so the DB itself does not support autocommit mode. (Strictly, there is an autocommit mode, but it is a different concept from the "autocommit" that we are used to with MySQL and others.)

Therefore, a transaction must have started before any operation is performed, and autocommit mode had to be emulated in PHP.

I made sure that a transaction always exists when in autocommit mode. Since the `in_transacntion` function does not work as expected, I have introduced `H->in_manually_txn` to determine whether a transaction is being manually manipulated.

## There are two types of commit/rollback

(I'm not talking about two-phase commit. This change does not take into account two-phase commit.)

There are `isc_commit_retaining` which starts a transaction again in the same context immediately after committing, and `isc_commit_transaction` which closes the transaction as is.

Similarly, there are two types of rollback.

-----------

Due to the default value of the transaction isolation level, autocommit mode may obtain unintended results.
Regarding this, it would be too large to include support for transaction isolation levels in this PR, so I will leave it as is for now.
---
 ext/pdo/tests/pdo_017.phpt                    |   1 -
 ext/pdo_firebird/firebird_driver.c            | 190 ++++++++++++++----
 ext/pdo_firebird/firebird_statement.c         |   3 +-
 ext/pdo_firebird/php_pdo_firebird_int.h       |   6 +-
 ext/pdo_firebird/tests/autocommit.phpt        |  80 ++++++++
 .../tests/autocommit_change_mode.phpt         | 134 ++++++++++++
 ext/pdo_firebird/tests/bug_47415.phpt         |   4 -
 ext/pdo_firebird/tests/bug_48877.phpt         |   2 -
 ext/pdo_firebird/tests/bug_53280.phpt         |   2 -
 ext/pdo_firebird/tests/bug_62024.phpt         |   6 -
 ext/pdo_firebird/tests/bug_64037.phpt         |   4 -
 ext/pdo_firebird/tests/ddl2.phpt              |  37 ++++
 ext/pdo_firebird/tests/payload_test.phpt      |   5 +-
 ext/pdo_firebird/tests/rowCount.phpt          |   4 -
 14 files changed, 405 insertions(+), 73 deletions(-)
 create mode 100644 ext/pdo_firebird/tests/autocommit.phpt
 create mode 100644 ext/pdo_firebird/tests/autocommit_change_mode.phpt
 create mode 100644 ext/pdo_firebird/tests/ddl2.phpt

diff --git a/ext/pdo/tests/pdo_017.phpt b/ext/pdo/tests/pdo_017.phpt
index bc514bff2c3..d24aff1c15f 100644
--- a/ext/pdo/tests/pdo_017.phpt
+++ b/ext/pdo/tests/pdo_017.phpt
@@ -8,7 +8,6 @@ $dir = getenv('REDIR_TEST_DIR');
 if (false == $dir) die('skip no driver');
 require_once $dir . 'pdo_test.inc';
 PDOTest::skip();
-if (str_starts_with(getenv('PDOTEST_DSN'), "firebird")) die('xfail firebird driver does not behave as expected');
 
 $db = PDOTest::factory();
 try {
diff --git a/ext/pdo_firebird/firebird_driver.c b/ext/pdo_firebird/firebird_driver.c
index bb9eb29ee91..8b4572970a2 100644
--- a/ext/pdo_firebird/firebird_driver.c
+++ b/ext/pdo_firebird/firebird_driver.c
@@ -33,6 +33,7 @@
 
 static int php_firebird_alloc_prepare_stmt(pdo_dbh_t*, const zend_string*, XSQLDA*, isc_stmt_handle*,
 	HashTable*);
+static bool php_firebird_rollback_transaction(pdo_dbh_t *dbh);
 
 const char CHR_LETTER = 1;
 const char CHR_DIGIT = 2;
@@ -526,17 +527,14 @@ static void firebird_handle_closer(pdo_dbh_t *dbh) /* {{{ */
 {
 	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
 
-	if (dbh->in_txn) {
+	if (H->tr) {
 		if (dbh->auto_commit) {
-			if (isc_commit_transaction(H->isc_status, &H->tr)) {
-				php_firebird_error(dbh);
-			}
+			php_firebird_commit_transaction(dbh, /* release */ false);
 		} else {
-			if (isc_rollback_transaction(H->isc_status, &H->tr)) {
-				php_firebird_error(dbh);
-			}
+			php_firebird_rollback_transaction(dbh);
 		}
 	}
+	H->in_manually_txn = 0;
 
 	if (isc_detach_database(H->isc_status, &H->db)) {
 		php_firebird_error(dbh);
@@ -702,9 +700,10 @@ static zend_long firebird_handle_doer(pdo_dbh_t *dbh, const zend_string *sql) /*
 		}
 	}
 
-	/* commit if we're in auto_commit mode */
-	if (dbh->auto_commit && isc_commit_retaining(H->isc_status, &H->tr)) {
-		php_firebird_error(dbh);
+	if (dbh->auto_commit && !H->in_manually_txn) {
+		if (!php_firebird_commit_transaction(dbh, /* retain */ true)) {
+			ret = -1;
+		}
 	}
 
 free_statement:
@@ -756,8 +755,8 @@ static zend_string* firebird_handle_quoter(pdo_dbh_t *dbh, const zend_string *un
 }
 /* }}} */
 
-/* called by PDO to start a transaction */
-static bool firebird_handle_begin(pdo_dbh_t *dbh) /* {{{ */
+/* php_firebird_begin_transaction */
+static bool php_firebird_begin_transaction(pdo_dbh_t *dbh) /* {{{ */
 {
 	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
 	char tpb[8] = { isc_tpb_version3 }, *ptpb = tpb+1;
@@ -809,12 +808,84 @@ static bool firebird_handle_begin(pdo_dbh_t *dbh) /* {{{ */
 }
 /* }}} */
 
-/* called by PDO to commit a transaction */
-static bool firebird_handle_commit(pdo_dbh_t *dbh) /* {{{ */
+/* called by PDO to start a transaction */
+static bool firebird_handle_manually_begin(pdo_dbh_t *dbh) /* {{{ */
 {
 	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
 
-	if (isc_commit_transaction(H->isc_status, &H->tr)) {
+	/**
+	 * If in autocommit mode and in transaction, we will need to close the transaction once.
+	 */
+	if (dbh->auto_commit && H->tr) {
+		if (!php_firebird_commit_transaction(dbh, /* release */ false)) {
+			return false;
+		}
+	}
+
+	if (!php_firebird_begin_transaction(dbh)) {
+		return false;
+	}
+	H->in_manually_txn = 1;
+	return true;
+}
+/* }}} */
+
+/* php_firebird_commit_transaction */
+bool php_firebird_commit_transaction(pdo_dbh_t *dbh, bool retain) /* {{{ */
+{
+	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
+
+	/**
+	 * `retaining` keeps the transaction open without closing it.
+	 *
+	 * firebird needs to always have a transaction open to emulate autocommit mode,
+	 * and in autocommit mode it keeps the transaction open.
+	 *
+	 * Same as close and then begin again, but use retain to save overhead.
+	 */
+	if (retain) {
+		if (isc_commit_retaining(H->isc_status, &H->tr)) {
+			php_firebird_error(dbh);
+			return false;
+		}
+	} else {
+		if (isc_commit_transaction(H->isc_status, &H->tr)) {
+			php_firebird_error(dbh);
+			return false;
+		}
+	}
+	return true;
+}
+/* }}} */
+
+/* called by PDO to commit a transaction */
+static bool firebird_handle_manually_commit(pdo_dbh_t *dbh) /* {{{ */
+{
+	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
+	if (!php_firebird_commit_transaction(dbh, /*release*/ false)) {
+		return false;
+	}
+
+	/**
+	 * If in autocommit mode, begin the transaction again
+	 * Reopen instead of retain because isolation level may change
+	 */
+	if (dbh->auto_commit) {
+		if (!php_firebird_begin_transaction(dbh)) {
+			return false;
+		}
+	}
+	H->in_manually_txn = 0;
+	return true;
+}
+/* }}} */
+
+/* php_firebird_rollback_transaction */
+static bool php_firebird_rollback_transaction(pdo_dbh_t *dbh) /* {{{ */
+{
+	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
+
+	if (isc_rollback_transaction(H->isc_status, &H->tr)) {
 		php_firebird_error(dbh);
 		return false;
 	}
@@ -823,14 +894,24 @@ static bool firebird_handle_commit(pdo_dbh_t *dbh) /* {{{ */
 /* }}} */
 
 /* called by PDO to rollback a transaction */
-static bool firebird_handle_rollback(pdo_dbh_t *dbh) /* {{{ */
+static bool firebird_handle_manually_rollback(pdo_dbh_t *dbh) /* {{{ */
 {
 	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
 
-	if (isc_rollback_transaction(H->isc_status, &H->tr)) {
-		php_firebird_error(dbh);
+	if (!php_firebird_rollback_transaction(dbh)) {
 		return false;
 	}
+
+	/**
+	 * If in autocommit mode, begin the transaction again
+	 * Reopen instead of retain because isolation level may change
+	 */
+	if (dbh->auto_commit) {
+		if (!php_firebird_begin_transaction(dbh)) {
+			return false;
+		}
+	}
+	H->in_manually_txn = 0;
 	return true;
 }
 /* }}} */
@@ -848,16 +929,6 @@ static int php_firebird_alloc_prepare_stmt(pdo_dbh_t *dbh, const zend_string *sq
 		return 0;
 	}
 
-	/* start a new transaction implicitly if auto_commit is enabled and no transaction is open */
-	if (dbh->auto_commit && !dbh->in_txn) {
-		/* dbh->transaction_flags = PDO_TRANS_READ_UNCOMMITTED; */
-
-		if (!firebird_handle_begin(dbh)) {
-			return 0;
-		}
-		dbh->in_txn = true;
-	}
-
 	/* allocate the statement */
 	if (isc_dsql_allocate_statement(H->isc_status, &H->db, s)) {
 		php_firebird_error(dbh);
@@ -898,21 +969,34 @@ static bool pdo_firebird_set_attribute(pdo_dbh_t *dbh, zend_long attr, zval *val
 					return false;
 				}
 
+				if (H->in_manually_txn) {
+					/* change auto commit mode with an open transaction is illegal, because
+						we won't know what to do with it */
+					pdo_raise_impl_error(dbh, NULL, "HY000", "Cannot change autocommit mode while a transaction is already open");
+					return false;
+				}
+
 				/* ignore if the new value equals the old one */
 				if (dbh->auto_commit ^ bval) {
-					if (dbh->in_txn) {
-						if (bval) {
-							/* turning on auto_commit with an open transaction is illegal, because
-							   we won't know what to do with it */
-							const char *msg = "Cannot enable auto-commit while a transaction is already open";
-							php_firebird_error_with_info(dbh, "HY000", strlen("HY000"), msg, strlen(msg));
-							return false;
-						} else {
-							/* close the transaction */
-							if (!firebird_handle_commit(dbh)) {
-								break;
+					if (bval) {
+						/* change to auto commit mode.
+						 * If the transaction is not started, start it.
+						 * However, this is a fallback since such a situation usually does not occur.
+						 */
+						if (!H->tr) {
+							if (!php_firebird_begin_transaction(dbh)) {
+								return false;
+							}
+						}
+					} else {
+						/* change to not auto commit mode.
+						 * close the transaction if exists.
+						 * However, this is a fallback since such a situation usually does not occur.
+						 */
+						if (H->tr) {
+							if (!php_firebird_commit_transaction(dbh, /* release */ false)) {
+								return false;
 							}
-							dbh->in_txn = false;
 						}
 					}
 					dbh->auto_commit = bval;
@@ -1058,14 +1142,27 @@ static void pdo_firebird_fetch_error_func(pdo_dbh_t *dbh, pdo_stmt_t *stmt, zval
 }
 /* }}} */
 
+/* {{{ firebird_in_manually_transaction */
+static bool pdo_firebird_in_manually_transaction(pdo_dbh_t *dbh)
+{
+	/**
+	 * we can tell if a transaction exists now by checking H->tr,
+	 * but which will always be true in autocommit mode.
+	 * So this function checks if there is currently a "manually begun transaction".
+	 */
+	pdo_firebird_db_handle *H = (pdo_firebird_db_handle *)dbh->driver_data;
+	return H->in_manually_txn;
+}
+/* }}} */
+
 static const struct pdo_dbh_methods firebird_methods = { /* {{{ */
 	firebird_handle_closer,
 	firebird_handle_preparer,
 	firebird_handle_doer,
 	firebird_handle_quoter,
-	firebird_handle_begin,
-	firebird_handle_commit,
-	firebird_handle_rollback,
+	firebird_handle_manually_begin,
+	firebird_handle_manually_commit,
+	firebird_handle_manually_rollback,
 	pdo_firebird_set_attribute,
 	NULL, /* last_id not supported */
 	pdo_firebird_fetch_error_func,
@@ -1073,7 +1170,7 @@ static const struct pdo_dbh_methods firebird_methods = { /* {{{ */
 	NULL, /* check_liveness */
 	NULL, /* get driver methods */
 	NULL, /* request shutdown */
-	NULL, /* in transaction, use PDO's internal tracking mechanism */
+	pdo_firebird_in_manually_transaction,
 	NULL /* get gc */
 };
 /* }}} */
@@ -1154,6 +1251,11 @@ static int pdo_firebird_handle_factory(pdo_dbh_t *dbh, zval *driver_options) /*
 				"HY000", H->isc_status[1], errmsg);
 	}
 
+	H->in_manually_txn = 0;
+	if (dbh->auto_commit && !H->tr) {
+		ret = php_firebird_begin_transaction(dbh);
+	}
+
 	if (!ret) {
 		firebird_handle_closer(dbh);
 	}
diff --git a/ext/pdo_firebird/firebird_statement.c b/ext/pdo_firebird/firebird_statement.c
index bc973171b2f..000c74d6dda 100644
--- a/ext/pdo_firebird/firebird_statement.c
+++ b/ext/pdo_firebird/firebird_statement.c
@@ -180,8 +180,7 @@ static int pdo_firebird_stmt_execute(pdo_stmt_t *stmt) /* {{{ */
 				;
 		}
 
-		/* commit? */
-		if (stmt->dbh->auto_commit && isc_commit_retaining(H->isc_status, &H->tr)) {
+		if (stmt->dbh->auto_commit && !S->H->in_manually_txn && !php_firebird_commit_transaction(stmt->dbh, /* retain */ true)) {
 			break;
 		}
 
diff --git a/ext/pdo_firebird/php_pdo_firebird_int.h b/ext/pdo_firebird/php_pdo_firebird_int.h
index c7a0087ed6d..af598eae98a 100644
--- a/ext/pdo_firebird/php_pdo_firebird_int.h
+++ b/ext/pdo_firebird/php_pdo_firebird_int.h
@@ -66,7 +66,6 @@ typedef struct {
 } pdo_firebird_error_info;
 
 typedef struct {
-
 	/* the result of the last API call */
 	ISC_STATUS isc_status[20];
 
@@ -75,6 +74,7 @@ typedef struct {
 
 	/* the transaction handle */
 	isc_tr_handle tr;
+	bool in_manually_txn;
 
 	/* date and time format strings, can be set by the set_attribute method */
 	char *date_format;
@@ -93,7 +93,6 @@ typedef struct {
 
 
 typedef struct {
-
 	/* the link that owns this statement */
 	pdo_firebird_db_handle *H;
 
@@ -122,7 +121,6 @@ typedef struct {
 
 	/* the output SQLDA */
 	XSQLDA out_sqlda; /* last member */
-
 } pdo_firebird_stmt;
 
 extern const pdo_driver_t pdo_firebird_driver;
@@ -136,6 +134,8 @@ extern void php_firebird_set_error(pdo_dbh_t *dbh, pdo_stmt_t *stmt, const char
 #define php_firebird_error_with_info(d,e,el,m,ml) php_firebird_set_error(d, NULL, e, el, m, ml)
 #define php_firebird_error_stmt_with_info(s,e,el,m,ml) php_firebird_set_error(s->dbh, s, e, el, m, ml)
 
+extern bool php_firebird_commit_transaction(pdo_dbh_t *dbh, bool retain);
+
 enum {
 	PDO_FB_ATTR_DATE_FORMAT = PDO_ATTR_DRIVER_SPECIFIC,
 	PDO_FB_ATTR_TIME_FORMAT,
diff --git a/ext/pdo_firebird/tests/autocommit.phpt b/ext/pdo_firebird/tests/autocommit.phpt
new file mode 100644
index 00000000000..5ba61e11f7a
--- /dev/null
+++ b/ext/pdo_firebird/tests/autocommit.phpt
@@ -0,0 +1,80 @@
+--TEST--
+PDO_Firebird: auto commit
+--EXTENSIONS--
+pdo_firebird
+--SKIPIF--
+<?php require('skipif.inc'); ?>
+--XLEAK--
+A bug in firebird causes a memory leak when calling `isc_attach_database()`.
+See https://github.com/FirebirdSQL/firebird/issues/7849
+--FILE--
+<?php
+/* Part of the error messages probably vary depending on the version of Firebird,
+ * so it won't check them in detail. */
+
+require("testdb.inc");
+$table = "autocommit_pdo_firebird";
+
+echo "========== in auto commit mode ==========\n";
+echo "auto commit mode ON\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+
+echo "create table and insert\n";
+$dbh->exec("CREATE TABLE {$table} (val INT)");
+$dbh->exec("INSERT INTO {$table} VALUES (35)");
+
+echo "new connection\n";
+unset($dbh);
+$dbh = new PDO(PDO_FIREBIRD_TEST_DSN, PDO_FIREBIRD_TEST_USER, PDO_FIREBIRD_TEST_PASS);
+
+$r = $dbh->query("SELECT * FROM {$table}");
+var_dump($r->fetchAll());
+
+echo "========== not in auto commit mode ==========\n";
+echo "auto commit mode OFF\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+
+echo "insert, expect error\n";
+try {
+    $dbh->exec("INSERT INTO {$table} VALUES (35)");
+} catch (PDOException $e) {
+    echo $e->getMessage()."\n\n";
+}
+
+echo "select, expect error\n";
+try {
+    $r = $dbh->query("SELECT * FROM {$table}");
+} catch (PDOException $e) {
+    echo $e->getMessage()."\n\n";
+}
+
+echo "done!";
+?>
+--CLEAN--
+<?php
+require 'testdb.inc';
+@$dbh->exec("DROP TABLE autocommit_pdo_firebird");
+?>
+--EXPECTF--
+========== in auto commit mode ==========
+auto commit mode ON
+create table and insert
+new connection
+array(1) {
+  [0]=>
+  array(2) {
+    ["VAL"]=>
+    int(35)
+    [0]=>
+    int(35)
+  }
+}
+========== not in auto commit mode ==========
+auto commit mode OFF
+insert, expect error
+SQLSTATE[08003]: Connection does not exist: %s
+
+select, expect error
+SQLSTATE[08003]: Connection does not exist: %s
+
+done!
diff --git a/ext/pdo_firebird/tests/autocommit_change_mode.phpt b/ext/pdo_firebird/tests/autocommit_change_mode.phpt
new file mode 100644
index 00000000000..4eacdaa6975
--- /dev/null
+++ b/ext/pdo_firebird/tests/autocommit_change_mode.phpt
@@ -0,0 +1,134 @@
+--TEST--
+PDO_Firebird: change auto commit
+--EXTENSIONS--
+pdo_firebird
+--SKIPIF--
+<?php require('skipif.inc'); ?>
+--XLEAK--
+A bug in firebird causes a memory leak when calling `isc_attach_database()`.
+See https://github.com/FirebirdSQL/firebird/issues/7849
+--FILE--
+<?php
+require("testdb.inc");
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+
+echo "========== not in manually transaction ==========\n";
+
+echo "auto commit ON from ON\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+echo "Success\n\n";
+
+echo "auto commit OFF from ON\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+echo "Success\n\n";
+
+echo "auto commit OFF from OFF\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+echo "Success\n\n";
+
+echo "auto commit ON from OFF\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+echo "Success\n\n";
+
+echo "========== in manually transaction ==========\n";
+
+echo "begin transaction\n";
+$dbh->beginTransaction();
+echo "\n";
+
+echo "auto commit ON from ON, expect error\n";
+try {
+    $dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+} catch (PDOException $e) {
+    var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+    echo $e->getMessage()."\n\n";
+}
+
+echo "auto commit OFF from ON, expect error\n";
+try {
+    $dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+} catch (PDOException $e) {
+    var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+    echo $e->getMessage()."\n\n";
+}
+
+echo "end transaction\n";
+$dbh->rollback();
+
+echo "auto commit OFF\n";
+$dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+
+echo "begin transaction\n";
+$dbh->beginTransaction();
+echo "\n";
+
+echo "auto commit ON from OFF, expect error\n";
+try {
+    $dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, true);
+} catch (PDOException $e) {
+    var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+    echo $e->getMessage()."\n\n";
+}
+
+echo "auto commit OFF from OFF, expect error\n";
+try {
+    $dbh->setAttribute(PDO::ATTR_AUTOCOMMIT, false);
+} catch (PDOException $e) {
+    var_dump($dbh->getAttribute(PDO::ATTR_AUTOCOMMIT));
+    echo $e->getMessage()."\n\n";
+}
+
+echo "end transaction\n";
+$dbh->rollback();
+echo "\n";
+
+echo "done!";
+?>
+--EXPECT--
+========== not in manually transaction ==========
+auto commit ON from ON
+int(1)
+Success
+
+auto commit OFF from ON
+int(0)
+Success
+
+auto commit OFF from OFF
+int(0)
+Success
+
+auto commit ON from OFF
+int(1)
+Success
+
+========== in manually transaction ==========
+begin transaction
+
+auto commit ON from ON, expect error
+int(1)
+SQLSTATE[HY000]: General error: Cannot change autocommit mode while a transaction is already open
+
+auto commit OFF from ON, expect error
+int(1)
+SQLSTATE[HY000]: General error: Cannot change autocommit mode while a transaction is already open
+
+end transaction
+auto commit OFF
+begin transaction
+
+auto commit ON from OFF, expect error
+int(0)
+SQLSTATE[HY000]: General error: Cannot change autocommit mode while a transaction is already open
+
+auto commit OFF from OFF, expect error
+int(0)
+SQLSTATE[HY000]: General error: Cannot change autocommit mode while a transaction is already open
+
+end transaction
+
+done!
diff --git a/ext/pdo_firebird/tests/bug_47415.phpt b/ext/pdo_firebird/tests/bug_47415.phpt
index e67a1b3f6da..6a7fc6ff7f7 100644
--- a/ext/pdo_firebird/tests/bug_47415.phpt
+++ b/ext/pdo_firebird/tests/bug_47415.phpt
@@ -16,8 +16,6 @@ $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);
 $dbh->exec('CREATE TABLE test47415 (idx int NOT NULL PRIMARY KEY, txt VARCHAR(20))');
 $dbh->exec('INSERT INTO test47415 VALUES(0, \'String0\')');
 
-$dbh->commit();
-
 $query = "SELECT idx, txt FROM test47415 ORDER by idx";
 $idx = $txt = 0;
 $stmt = $dbh->prepare($query);
@@ -32,8 +30,6 @@ var_dump($stmt->rowCount());
 $stmt = $dbh->prepare('DELETE FROM test47415');
 $stmt->execute();
 
-$dbh->commit();
-
 unset($stmt);
 unset($dbh);
 ?>
diff --git a/ext/pdo_firebird/tests/bug_48877.phpt b/ext/pdo_firebird/tests/bug_48877.phpt
index ecdd40baa8d..f7fa25ba1c8 100644
--- a/ext/pdo_firebird/tests/bug_48877.phpt
+++ b/ext/pdo_firebird/tests/bug_48877.phpt
@@ -18,7 +18,6 @@ $dbh->exec('CREATE TABLE test48877 (A integer)');
 $dbh->exec("INSERT INTO test48877 VALUES ('1')");
 $dbh->exec("INSERT INTO test48877 VALUES ('2')");
 $dbh->exec("INSERT INTO test48877 VALUES ('3')");
-$dbh->commit();
 
 $query = "SELECT * FROM test48877 WHERE A = :paramno";
 
@@ -33,7 +32,6 @@ var_dump($stmt->rowCount());
 $stmt = $dbh->prepare('DELETE FROM test48877');
 $stmt->execute();
 
-$dbh->commit();
 unset($stmt);
 unset($dbh);
 
diff --git a/ext/pdo_firebird/tests/bug_53280.phpt b/ext/pdo_firebird/tests/bug_53280.phpt
index 4b22ec4fa16..b1da6789ba8 100644
--- a/ext/pdo_firebird/tests/bug_53280.phpt
+++ b/ext/pdo_firebird/tests/bug_53280.phpt
@@ -14,7 +14,6 @@ require("testdb.inc");
 
 $dbh->exec('CREATE TABLE test53280(A VARCHAR(30), B VARCHAR(30), C VARCHAR(30))');
 $dbh->exec("INSERT INTO test53280 VALUES ('A', 'B', 'C')");
-$dbh->commit();
 
 $stmt1 = "SELECT B FROM test53280 WHERE A = ? AND B = ?";
 $stmt2 = "SELECT B, C FROM test53280 WHERE A = ? AND B = ?";
@@ -29,7 +28,6 @@ $stmth1->execute(array('A', 'B'));
 $rows = $stmth1->fetchAll(); // <------- segfault
 var_dump($rows);
 
-$dbh->commit();
 unset($stmth1);
 unset($stmth2);
 unset($stmt);
diff --git a/ext/pdo_firebird/tests/bug_62024.phpt b/ext/pdo_firebird/tests/bug_62024.phpt
index 9817e550ffc..2f8fa09a936 100644
--- a/ext/pdo_firebird/tests/bug_62024.phpt
+++ b/ext/pdo_firebird/tests/bug_62024.phpt
@@ -15,8 +15,6 @@ require("testdb.inc");
 $dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);
 $dbh->exec("CREATE TABLE test62024 (ID INTEGER NOT NULL, TEXT VARCHAR(10))");
 
-$dbh->commit();
-
 //start actual test
 
 $sql = "insert into test62024 (id, text) values (?, ?)";
@@ -31,15 +29,11 @@ var_dump($res);
 $res = $sttmt->execute($args_err);
 var_dump($res);
 
-$dbh->commit();
-
 
 //teardown test data
 $sttmt = $dbh->prepare('DELETE FROM test62024');
 $sttmt->execute();
 
-$dbh->commit();
-
 unset($sttmt);
 unset($dbh);
 
diff --git a/ext/pdo_firebird/tests/bug_64037.phpt b/ext/pdo_firebird/tests/bug_64037.phpt
index c37268352cd..545e6feaf69 100644
--- a/ext/pdo_firebird/tests/bug_64037.phpt
+++ b/ext/pdo_firebird/tests/bug_64037.phpt
@@ -18,8 +18,6 @@ $dbh->exec("INSERT INTO test64037 (ID, TEXT, COST) VALUES (1, 'test', -1.0)");
 $dbh->exec("INSERT INTO test64037 (ID, TEXT, COST) VALUES (2, 'test', -0.99)");
 $dbh->exec("INSERT INTO test64037 (ID, TEXT, COST) VALUES (3, 'test', -1.01)");
 
-$dbh->commit();
-
 $query = "SELECT * from test64037 order by ID";
 $stmt = $dbh->prepare($query);
 $stmt->execute();
@@ -32,8 +30,6 @@ var_dump($rows[2]['COST']);
 $stmt = $dbh->prepare('DELETE FROM test64037');
 $stmt->execute();
 
-$dbh->commit();
-
 unset($stmt);
 unset($dbh);
 
diff --git a/ext/pdo_firebird/tests/ddl2.phpt b/ext/pdo_firebird/tests/ddl2.phpt
new file mode 100644
index 00000000000..f258fb6f930
--- /dev/null
+++ b/ext/pdo_firebird/tests/ddl2.phpt
@@ -0,0 +1,37 @@
+--TEST--
+PDO_Firebird: DDL/transactions 2
+--EXTENSIONS--
+pdo_firebird
+--SKIPIF--
+<?php require('skipif.inc'); ?>
+--XLEAK--
+A bug in firebird causes a memory leak when calling `isc_attach_database()`.
+See https://github.com/FirebirdSQL/firebird/issues/7849
+--FILE--
+<?php
+require("testdb.inc");
+
+$dbh->exec("CREATE TABLE test_ddl2 (val int)");
+
+$dbh->beginTransaction();
+$dbh->exec("INSERT INTO test_ddl2 (val) VALUES (120)");
+$dbh->exec("CREATE TABLE test_ddl2_2 (val INT)");
+$dbh->rollback();
+
+$result = $dbh->query("SELECT * FROM test_ddl2");
+var_dump($result->fetchAll());
+
+unset($dbh);
+echo "done\n";
+?>
+--CLEAN--
+<?php
+require("testdb.inc");
+$dbh->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_WARNING);
+@$dbh->exec('DROP TABLE test_ddl2');
+@$dbh->exec('DROP TABLE test_ddl2_2');
+?>
+--EXPECT--
+array(0) {
+}
+done
diff --git a/ext/pdo_firebird/tests/payload_test.phpt b/ext/pdo_firebird/tests/payload_test.phpt
index 027c101d80b..e119a4068f6 100644
--- a/ext/pdo_firebird/tests/payload_test.phpt
+++ b/ext/pdo_firebird/tests/payload_test.phpt
@@ -17,6 +17,9 @@ $dsn = "firebird:dbname=inet://$address/test";
 $username = 'SYSDBA';
 $password = 'masterkey';
 
-new PDO($dsn, $username, $password, [PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION]);
+new PDO($dsn, $username, $password, [
+    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION,
+    PDO::ATTR_AUTOCOMMIT => false,
+]);
 ?>
 --EXPECT--
diff --git a/ext/pdo_firebird/tests/rowCount.phpt b/ext/pdo_firebird/tests/rowCount.phpt
index ec6748dd143..d435cc10a24 100644
--- a/ext/pdo_firebird/tests/rowCount.phpt
+++ b/ext/pdo_firebird/tests/rowCount.phpt
@@ -16,7 +16,6 @@ $dbh->exec('CREATE TABLE test_rowcount (A VARCHAR(10))');
 $dbh->exec("INSERT INTO test_rowcount VALUES ('A')");
 $dbh->exec("INSERT INTO test_rowcount VALUES ('A')");
 $dbh->exec("INSERT INTO test_rowcount VALUES ('B')");
-$dbh->commit();
 
 $query = "SELECT * FROM test_rowcount WHERE A = ?";
 
@@ -30,14 +29,11 @@ var_dump($stmt->rowCount());
 $stmt = $dbh->prepare('UPDATE test_rowcount SET A="A" WHERE A != ?');
 $stmt->execute(array('A'));
 var_dump($stmt->rowCount());
-$dbh->commit();
 
 $stmt = $dbh->prepare('DELETE FROM test_rowcount');
 $stmt->execute();
 var_dump($stmt->rowCount());
 
-$dbh->commit();
-
 unset($stmt);
 unset($dbh);