Avoid invalid array access

Author: adoy

src/Adoy/FastCGI/Client.php

@@ -538,9 +538,7 @@ public function wait_for_response($requestId, $timeoutMs = 0) {
         // but still not get the response requested
         $startTime = microtime(true);
 
-        do {
-            $resp = $this->readPacket();
-
+        while ($resp = $this->readPacket()) {
             if ($resp['type'] == self::STDOUT || $resp['type'] == self::STDERR) {
                 if ($resp['type'] == self::STDERR) {
                     $this->_requests[$resp['requestId']]['state'] = self::REQ_STATE_ERR;
@@ -549,7 +547,7 @@ public function wait_for_response($requestId, $timeoutMs = 0) {
             }
             if ($resp['type'] == self::END_REQUEST) {
                 $this->_requests[$resp['requestId']]['state'] = self::REQ_STATE_OK;
-                if ($resp['requestId'] == $requestId) { 
+                if ($resp['requestId'] == $requestId) {
                     break;
                 }
             }
@@ -558,7 +556,7 @@ public function wait_for_response($requestId, $timeoutMs = 0) {
                 $this->set_ms_timeout($this->_readWriteTimeout);
                 throw new \Exception('Timed out');
             }
-        } while ($resp);
+        }
 
         if (!is_array($resp)) {
             $info = stream_get_meta_data($this->_sock);