Fixed bug #80458

If there is no result set (e.g. for upsert queries), still allow
fetching to occur without error, i.e. treat it the same way as
an empty result set.

This normalizes behavior between native and emulated prepared
statements and addresses a regression in PHP 7.4.13.

3 files changed, 200 insertions, 11 deletions

diff --git a/NEWS b/NEWS
index c7fe41fd88..dab2198b9b 100644
--- a/NEWS
+++ b/NEWS
@@ -28,6 +28,10 @@ PHP                                                                        NEWS
   . Fixed bug #73809 (Phar Zip parse crash - mmap fail). (cmb)
   . Fixed #75102 (`PharData` says invalid checksum for valid tar). (cmb)
 
+- PDO MySQL:
+  . Fixed bug #80458 (PDOStatement::fetchAll() throws for upsert queries).
+    (Kamil Tekiela)
+
 - Phpdbg:
   . Fixed bug #76813 (Access violation near NULL on source operand). (cmb)
 
diff --git a/ext/pdo_mysql/mysql_statement.c b/ext/pdo_mysql/mysql_statement.c
index dbac374171..58711459ae 100644
--- a/ext/pdo_mysql/mysql_statement.c
+++ b/ext/pdo_mysql/mysql_statement.c
@@ -621,7 +621,12 @@ static int pdo_mysql_stmt_param_hook(pdo_stmt_t *stmt, struct pdo_bound_param_da
 static int pdo_mysql_stmt_fetch(pdo_stmt_t *stmt, enum pdo_fetch_orientation ori, zend_long offset) /* {{{ */
 {
 	pdo_mysql_stmt *S = (pdo_mysql_stmt*)stmt->driver_data;
-#if PDO_USE_MYSQLND
+
+	if (!S->result) {
+		PDO_DBG_RETURN(0);
+	}
+
+#ifdef PDO_USE_MYSQLND
 	zend_bool fetched_anything;
 
 	PDO_DBG_ENTER("pdo_mysql_stmt_fetch");
@@ -634,6 +639,10 @@ static int pdo_mysql_stmt_fetch(pdo_stmt_t *stmt, enum pdo_fetch_orientation ori
 
 		PDO_DBG_RETURN(1);
 	}
+
+	if (!S->stmt && S->current_data) {
+		mnd_free(S->current_data);
+	}
 #else
 	int ret;
 
@@ -657,16 +666,6 @@ static int pdo_mysql_stmt_fetch(pdo_stmt_t *stmt, enum pdo_fetch_orientation ori
 	}
 #endif /* PDO_USE_MYSQLND */
 
-	if (!S->result) {
-		strcpy(stmt->error_code, "HY000");
-		PDO_DBG_RETURN(0);
-	}
-#if PDO_USE_MYSQLND
-	if (!S->stmt && S->current_data) {
-		mnd_free(S->current_data);
-	}
-#endif /* PDO_USE_MYSQLND */
-
 	if ((S->current_data = mysql_fetch_row(S->result)) == NULL) {
 		if (!S->H->buffered && mysql_errno(S->H->server)) {
 			pdo_mysql_error_stmt(stmt);
diff --git a/ext/pdo_mysql/tests/bug80458.phpt b/ext/pdo_mysql/tests/bug80458.phpt
new file mode 100644
index 0000000000..86e171d302
--- /dev/null
+++ b/ext/pdo_mysql/tests/bug80458.phpt
@@ -0,0 +1,186 @@
+--TEST--
+Bug #80458 PDOStatement::fetchAll() throws for upsert queries
+--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');
+
+$db = MySQLPDOTest::factory();
+$db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+$db->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
+
+$db->query('DROP TABLE IF EXISTS test');
+$db->query('CREATE TABLE test (first int) ENGINE = InnoDB');
+$res = $db->query('INSERT INTO test(first) VALUES (1),(2),(3),(4),(5),(6),(7),(8),(9),(10),(11),(12),(13),(14),(15),(16)');
+var_dump($res->fetchAll());
+
+$stmt = $db->prepare('DELETE FROM test WHERE first=1');
+$stmt->execute();
+var_dump($stmt->fetchAll());
+
+$res = $db->query('DELETE FROM test WHERE first=2');
+var_dump($res->fetchAll());
+
+$stmt2 = $db->prepare('DELETE FROM test WHERE first=3');
+$stmt2->execute();
+foreach($stmt2 as $row){
+    // expect nothing
+}
+
+$stmt3 = $db->prepare('DELETE FROM test WHERE first=4');
+$stmt3->execute();
+var_dump($stmt3->fetch(PDO::FETCH_ASSOC));
+
+$stmt = $db->prepare('SELECT first FROM test WHERE first=5');
+$stmt->execute();
+var_dump($stmt->fetchAll());
+
+$db->exec('DROP PROCEDURE IF EXISTS nores');
+$db->exec('CREATE PROCEDURE nores() BEGIN DELETE FROM test WHERE first=6; END;');
+$stmt4 = $db->prepare('CALL nores()');
+$stmt4->execute();
+var_dump($stmt4->fetchAll());
+$db->exec('DROP PROCEDURE IF EXISTS nores');
+
+$db->exec('DROP PROCEDURE IF EXISTS ret');
+$db->exec('CREATE PROCEDURE ret() BEGIN SELECT first FROM test WHERE first=7; END;');
+$stmt5 = $db->prepare('CALL ret()');
+$stmt5->execute();
+var_dump($stmt5->fetchAll());
+$stmt5->nextRowset(); // needed to fetch the empty result set of CALL
+var_dump($stmt5->fetchAll());
+$db->exec('DROP PROCEDURE IF EXISTS ret');
+
+/* With emulated prepares */
+print("Emulated prepares\n");
+$db->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
+
+$stmt = $db->prepare('DELETE FROM test WHERE first=8');
+$stmt->execute();
+var_dump($stmt->fetchAll());
+
+$res = $db->query('DELETE FROM test WHERE first=9');
+var_dump($res->fetchAll());
+
+$stmt2 = $db->prepare('DELETE FROM test WHERE first=10');
+$stmt2->execute();
+foreach($stmt2 as $row){
+    // expect nothing
+}
+
+$stmt3 = $db->prepare('DELETE FROM test WHERE first=11');
+$stmt3->execute();
+var_dump($stmt3->fetch(PDO::FETCH_ASSOC));
+
+$stmt = $db->prepare('SELECT first FROM test WHERE first=12');
+$stmt->execute();
+var_dump($stmt->fetchAll());
+
+$db->exec('DROP PROCEDURE IF EXISTS nores');
+$db->exec('CREATE PROCEDURE nores() BEGIN DELETE FROM test WHERE first=13; END;');
+$stmt4 = $db->prepare('CALL nores()');
+$stmt4->execute();
+var_dump($stmt4->fetchAll());
+$db->exec('DROP PROCEDURE IF EXISTS nores');
+
+$db->exec('DROP PROCEDURE IF EXISTS ret');
+$db->exec('CREATE PROCEDURE ret() BEGIN SELECT first FROM test WHERE first=14; END;');
+$stmt5 = $db->prepare('CALL ret()');
+$stmt5->execute();
+var_dump($stmt5->fetchAll());
+$stmt5->nextRowset(); // needed to fetch the empty result set of CALL
+var_dump($stmt5->fetchAll());
+$db->exec('DROP PROCEDURE IF EXISTS ret');
+
+$db->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
+$db->setAttribute(PDO::MYSQL_ATTR_USE_BUFFERED_QUERY, false);
+
+$stmt = $db->prepare('DELETE FROM test WHERE first=15');
+$stmt->execute();
+var_dump($stmt->fetchAll());
+
+$stmt = $db->prepare('SELECT first FROM test WHERE first=16');
+$stmt->execute();
+var_dump($stmt->fetchAll());
+
+?>
+--CLEAN--
+<?php
+require __DIR__ . '/mysql_pdo_test.inc';
+MySQLPDOTest::dropTestTable();
+?>
+--EXPECT--
+array(0) {
+}
+array(0) {
+}
+array(0) {
+}
+bool(false)
+array(1) {
+  [0]=>
+  array(2) {
+    ["first"]=>
+    int(5)
+    [0]=>
+    int(5)
+  }
+}
+array(0) {
+}
+array(1) {
+  [0]=>
+  array(2) {
+    ["first"]=>
+    int(7)
+    [0]=>
+    int(7)
+  }
+}
+array(0) {
+}
+Emulated prepares
+array(0) {
+}
+array(0) {
+}
+bool(false)
+array(1) {
+  [0]=>
+  array(2) {
+    ["first"]=>
+    string(2) "12"
+    [0]=>
+    string(2) "12"
+  }
+}
+array(0) {
+}
+array(1) {
+  [0]=>
+  array(2) {
+    ["first"]=>
+    string(2) "14"
+    [0]=>
+    string(2) "14"
+  }
+}
+array(0) {
+}
+array(0) {
+}
+array(1) {
+  [0]=>
+  array(2) {
+    ["first"]=>
+    int(16)
+    [0]=>
+    int(16)
+  }
+}