edit

lib/Wechat.php

@@ -121,7 +121,7 @@ class Wechat extends Core
 			$string['noncestr'] = $order['nonce_str'];
 			$string['timestamp'] = $order['time'];
 			ksort($string);
-			$string = http_build_query($string);
+			$string = str_replace('%3D', '=', http_build_query($string));
 			$this->log('支付签名-app', $string);
 			if($order['sign_type'] == "MD5"){
 				$string = md5($string);