Fix for Bug #55582 mysqli_num_rows() returns always 0 for unbuffered, when mysqlnd is used

ext/mysqli/mysqli_api.c

@@ -1612,7 +1612,7 @@ PHP_FUNCTION(mysqli_num_rows)
 	}
 	MYSQLI_FETCH_RESOURCE(result, MYSQL_RES *, &mysql_result, "mysqli_result", MYSQLI_STATUS_VALID);
 
-	if (mysqli_result_is_unbuffered(result)) {
+	if (mysqli_result_is_unbuffered_and_not_everything_is_fetched(result)) {
 		php_error_docref(NULL TSRMLS_CC, E_WARNING, "Function cannot be used with MYSQL_USE_RESULT");
 		RETURN_LONG(0);
 	}

ext/mysqli/mysqli_libmysql.h

@@ -30,6 +30,7 @@
 
 /* r->data should be always NULL, at least in recent libmysql versions, the status changes once data is read*/
 #define mysqli_result_is_unbuffered(r)		(((r)->handle && (r)->handle->status == MYSQL_STATUS_USE_RESULT) || ((r)->data == NULL))
+#define mysqli_result_is_unbuffered_and_not_everything_is_fetched(r)		(((r)->handle && (r)->handle->status == MYSQL_STATUS_USE_RESULT) || ((r)->data == NULL))
 #define mysqli_server_status(c)				(c)->server_status
 #define mysqli_stmt_get_id(s)				((s)->stmt_id)
 #define mysqli_stmt_warning_count(s)		mysql_warning_count((s)->mysql)

ext/mysqli/mysqli_mysqlnd.h

@@ -31,6 +31,7 @@
 #define MYSQLI_CLOSE_DISCONNECTED              MYSQLND_CLOSE_DISCONNECTED
 
 #define mysqli_result_is_unbuffered(r)	((r)->unbuf)
+#define mysqli_result_is_unbuffered_and_not_everything_is_fetched(r)	((r)->unbuf && !(r)->unbuf->eof_reached)
 #define mysqli_server_status(c)			(c)->upsert_status.server_status
 #define mysqli_stmt_get_id(s)			((s)->data->stmt_id)
 #define mysqli_stmt_warning_count(s)	mysqlnd_stmt_warning_count((s))

ext/mysqli/mysqli_result_iterator.c

@@ -133,7 +133,7 @@ static void php_mysqli_result_iterator_rewind(zend_object_iterator *iter TSRMLS_
 
 	if (mysqli_result_is_unbuffered(result)) {
 #if MYSQLI_USE_MYSQLND
-		if (result->unbuf && result->unbuf->eof_reached) {
+		if (result->unbuf->eof_reached) {
 #else
 		if (result->eof) {
 #endif

ext/mysqli/tests/bug55582.phpt

@@ -0,0 +1,41 @@
+--TEST--
+Bug #55582 mysqli_num_rows() returns always 0 for unbuffered, when mysqlnd is used
+--SKIPIF--
+<?php
+require_once('skipif.inc');
+require_once('skipifconnectfailure.inc');
+require_once("connect.inc");
+?>
+--FILE--
+<?php
+	include "connect.inc";
+	if (!($link = my_mysqli_connect($host, $user, $passwd, $db, $port, $socket))) {
+		printf("[001] Cannot connect to the server");
+	}
+	
+	var_dump($link->real_query("SELECT 1"));
+	$res = $link->use_result();
+	var_dump(mysqli_num_rows($res));
+	var_dump($res->fetch_assoc());
+	var_dump(mysqli_num_rows($res));
+	var_dump($res->fetch_assoc());
+	var_dump(mysqli_num_rows($res));
+
+	$link->close();
+	echo "done\n";
+?>
+--EXPECTF--
+bool(true)
+
+Warning: mysqli_num_rows(): Function cannot be used with MYSQL_USE_RESULT in %s on line %d
+int(0)
+array(1) {
+  [1]=>
+  string(1) "1"
+}
+
+Warning: mysqli_num_rows(): Function cannot be used with MYSQL_USE_RESULT in %s on line %d
+int(0)
+NULL
+int(1)
+done

ext/mysqlnd/mysqlnd_result.c

@@ -601,19 +601,18 @@ mysqlnd_fetch_lengths_buffered(MYSQLND_RES * const result TSRMLS_DC)
 static unsigned long *
 mysqlnd_fetch_lengths_unbuffered(MYSQLND_RES * const result TSRMLS_DC)
 {
-	return result->lengths;
+	/* simulate output of libmysql */
+	return (!result->unbuf || result->unbuf->last_row_data || result->unbuf->eof_reached)? result->lengths:NULL;
 }
 /* }}} */
 
 
-#if !defined(MYSQLND_USE_OPTIMISATIONS) || MYSQLND_USE_OPTIMISATIONS == 0
 /* {{{ mysqlnd_res::fetch_lengths */
 PHPAPI unsigned long * _mysqlnd_fetch_lengths(MYSQLND_RES * const result TSRMLS_DC)
 {
 	return result->m.fetch_lengths? result->m.fetch_lengths(result TSRMLS_CC) : NULL;
 }
 /* }}} */
-#endif
 
 
 /* {{{ mysqlnd_fetch_row_unbuffered_c */