PDO: Honor ATTR_STRINGIFY_FETCHES for booleans

Of the important PDO drivers, this affects only PDO PgSQL, as
both MySQL and SQLite do not return native boolean types.

Author: nikic

UPGRADING

@@ -35,6 +35,10 @@ PHP 8.1 UPGRADE NOTES
   . The mysqlnd.fetch_copy_data ini setting has been removed. However, this
     should not result in user-visible behavior changes.
 
+- PDO:
+  . PDO::ATTR_STRINGIFY_FETCHES now also stringifies values of type bool to
+    "0" or "1". Previously booleans were not stringified.
+
 - PDO MySQL:
   . Integers and floats in result sets will now be returned using native PHP
     types instead of strings when using emulated prepared statements. This

ext/pdo/pdo_stmt.c

@@ -616,6 +616,13 @@ static inline void fetch_value(pdo_stmt_t *stmt, zval *dest, int colno, int *typ
 
 	if (stmt->dbh->stringify) {
 		switch (Z_TYPE_P(dest)) {
+			case IS_FALSE:
+				/* Return "0" rather than "", because this is what database drivers that
+				 * don't have a dedicated boolean type would return. */
+				zval_ptr_dtor_nogc(dest);
+				ZVAL_INTERNED_STR(dest, ZSTR_CHAR('0'));
+				break;
+			case IS_TRUE:
 			case IS_LONG:
 			case IS_DOUBLE:
 				convert_to_string(dest);

ext/pdo_pgsql/tests/bug62593.phpt

@@ -13,6 +13,7 @@ require __DIR__ . '/../../../ext/pdo/tests/pdo_test.inc';
 $db = PDOTest::test_factory(__DIR__ . '/common.phpt');
 $db->setAttribute(PDO::ATTR_EMULATE_PREPARES, true);
 $db->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_SILENT);
+$db->setAttribute(PDO::ATTR_STRINGIFY_FETCHES, false);
 $errors = array();
 
 $value = true;

ext/pdo_pgsql/tests/bug71885.phpt

@@ -37,10 +37,10 @@ foreach ([false, true] as $emulate) {
 string(3) "ERR"
 array(1) {
   [0]=>
-  bool(true)
+  string(1) "1"
 }
 array(1) {
   [0]=>
-  bool(true)
+  string(1) "1"
 }
 ==OK==

ext/pdo_pgsql/tests/bug71885_2.phpt

@@ -40,18 +40,18 @@ foreach ([false, true] as $emulate) {
 --EXPECT--
 array(1) {
   [0]=>
-  bool(false)
+  string(1) "0"
 }
 array(1) {
   [0]=>
-  bool(true)
+  string(1) "1"
 }
 array(1) {
   [0]=>
-  bool(false)
+  string(1) "0"
 }
 array(1) {
   [0]=>
-  bool(true)
+  string(1) "1"
 }
 ==OK==

ext/pdo_pgsql/tests/bug75402.phpt

@@ -105,7 +105,7 @@ object(stdClass)#2 (1) {
       ["sprogress"]=>
       string(3) "100"
       ["bhidden"]=>
-      bool(false)
+      string(1) "0"
       ["sdatetime"]=>
       string(19) "2017.10.16 08:36:45"
     }