fix(openai-ws): classify canceled client streams

backend/internal/handler/openai_client_disconnect_test.go

@@ -0,0 +1,25 @@
+package handler
+
+import (
+	"context"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+
+	"github.com/gin-gonic/gin"
+	"github.com/stretchr/testify/require"
+)
+
+func TestOpenAIEnsureForwardErrorResponse_SkipsCanceledClient(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	recorder := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(recorder)
+	ctx, cancel := context.WithCancel(context.Background())
+	c.Request = httptest.NewRequest(http.MethodPost, EndpointResponses, nil).WithContext(ctx)
+	cancel()
+
+	h := &OpenAIGatewayHandler{}
+	require.False(t, h.ensureForwardErrorResponse(c, true))
+	require.Equal(t, statusClientClosedRequest, c.Writer.Status())
+	require.Empty(t, recorder.Body.String())
+}

backend/internal/handler/openai_gateway_handler.go

@@ -792,6 +792,22 @@ func (h *OpenAIGatewayHandler) Responses(c *gin.Context) {
 			})
 		}
 		if err != nil {
+			if result != nil && result.ClientDisconnect {
+				reqLog.Info("openai.client_disconnected",
+					zap.Int64("account_id", account.ID),
+					zap.Error(err),
+				)
+				submitResponsesUsage(result)
+				return
+			}
+			if failoverClientGone(c) {
+				reqLog.Info("openai.client_disconnected",
+					zap.Int64("account_id", account.ID),
+					zap.Error(err),
+				)
+				submitResponsesUsage(result)
+				return
+			}
 			if result != nil && result.ImageCount > 0 {
 				reqLog.Warn("openai.forward_partial_error_with_image_result",
 					zap.Int64("account_id", account.ID),
@@ -3087,6 +3103,10 @@ func (h *OpenAIGatewayHandler) ensureForwardErrorResponse(c *gin.Context, stream
 	if c == nil || c.Writer == nil {
 		return false
 	}
+	if c.Request != nil && errors.Is(c.Request.Context().Err(), context.Canceled) {
+		failoverClientGone(c)
+		return false
+	}
 	// 先停 compact 心跳再读 Writer 状态，避免与心跳 goroutine 竞争。
 	compactKeepaliveCommitted := service.StopOpenAICompactSSEKeepaliveCommitted(c)
 	if compactKeepaliveCommitted {