更新

server/tests/PrescriptionAiUpstreamContractTest.php

@@ -192,6 +192,40 @@ expectSame(false, callPrivate('shouldRetryWithoutFiles', [400, []]), 'a text-onl
 expectSame(false, callPrivate('shouldRetryWithoutFiles', [401, $capped['kept']]), 'a credential failure is not retried');
 expectSame(false, callPrivate('shouldRetryWithoutFiles', [500, $capped['kept']]), 'an upstream outage is not retried here');
 
+// 协议回退会把最初的“附件被拒”换成另一协议的状态码（Dify 400 -> OpenAI 404），
+// 降级判断必须按每次响应累计，否则去掉附件的重试永远不会发生。
+expectSame(
+    true,
+    callPrivate('isFileRejection', [['errno' => 0, 'http_code' => 400], $capped['kept']]),
+    'an attachment rejection is recognised on the response that carried it'
+);
+expectSame(
+    false,
+    callPrivate('isFileRejection', [['errno' => 0, 'http_code' => 404], $capped['kept']]),
+    'the fallback protocol 404 is not itself an attachment rejection'
+);
+expectSame(
+    true,
+    callPrivate('isFileRejection', [
+        ['errno' => 0, 'http_code' => 200, 'upstream_error' => true],
+        $capped['kept'],
+    ]),
+    'a 200 stream carrying event:error counts as an attachment rejection'
+);
+expectSame(
+    false,
+    callPrivate('isFileRejection', [
+        ['errno' => 0, 'http_code' => 200, 'upstream_error' => true],
+        [],
+    ]),
+    'a text-only request never degrades further'
+);
+expectSame(
+    false,
+    callPrivate('isFileRejection', [['errno' => 28, 'http_code' => 0], $capped['kept']]),
+    'a transport failure is not mistaken for an attachment rejection'
+);
+
 // Dify 的 inputs 必须是 JSON 对象。PHP 空数组会被编码成 []，上游以
 // invalid_param 拒绝整单——空 inputs 的调用方会 100% 失败。
 $emptyInputs = callPrivate('buildRequestSpecs', [