Fix #977: Handle the exception as structured even if the reason is null

Author: oogFranz

src/Elasticsearch/Connections/Connection.php

@@ -679,8 +679,15 @@ private function tryDeserializeError(array $response, string $errorClass): Elast
     {
         $error = $this->serializer->deserialize($response['body'], $response['transfer_stats']);
         if (is_array($error) === true) {
+            if (isset($error['error']) === false){
+                // <2.0 "i just blew up" nonstructured exception
+                // $error is an array but we don't know the format, reuse the response body instead
+                // added json_encode to convert into a string
+                return new $errorClass(json_encode($response['body']), (int) $response['status']);
+            }
+
             // 2.0 structured exceptions
-            if (isset($error['error']['reason']) === true) {
+            if (is_array($error['error']) && array_key_exists('reason', $error['error']) === true) {
                 // Try to use root cause first (only grabs the first root cause)
                 $root = $error['error']['root_cause'];
                 if (isset($root) && isset($root[0])) {
@@ -694,18 +701,12 @@ private function tryDeserializeError(array $response, string $errorClass): Elast
                 $original = new $errorClass(json_encode($response['body']), $response['status']);
 
                 return new $errorClass("$type: $cause", (int) $response['status'], $original);
-            } elseif (isset($error['error']) === true) {
-                // <2.0 semi-structured exceptions
-                // added json_encode to convert into a string
-                $original = new $errorClass(json_encode($response['body']), $response['status']);
-
-                return new $errorClass($error['error'], (int) $response['status'], $original);
             }
-
-            // <2.0 "i just blew up" nonstructured exception
-            // $error is an array but we don't know the format, reuse the response body instead
+            // <2.0 semi-structured exceptions
             // added json_encode to convert into a string
-            return new $errorClass(json_encode($response['body']), (int) $response['status']);
+            $original = new $errorClass(json_encode($response['body']), $response['status']);
+
+            return new $errorClass($error['error'], (int) $response['status'], $original);
         }
 
         // if responseBody is not string, we convert it so it can be used as Exception message