Merge 30a1dadcb0ae02dbfe894ab8c78b8ec22b79b694 into d9307dbcbbe796a64d9e0ef23452da888dd7f904

gin.go

@@ -122,6 +122,13 @@ type Engine struct {
 	// handler.
 	HandleMethodNotAllowed bool
 
+	// SkipMethodNotAllowedMiddleware if enabled, global middleware registered via Use()
+	// will not be executed for 405 Method Not Allowed responses. This allows
+	// NoMethod handlers to run without triggering middleware that may reject
+	// the request (e.g., authentication, checksum validation) before the 405
+	// response can be sent.
+	SkipMethodNotAllowedMiddleware bool
+
 	// ForwardedByClientIP if enabled, client IP will be parsed from the request's headers that
 	// match those stored at `(*gin.Engine).RemoteIPHeaders`. If no IP was
 	// fetched, it falls back to the IP obtained from
@@ -358,6 +365,10 @@ func (engine *Engine) rebuild404Handlers() {
 }
 
 func (engine *Engine) rebuild405Handlers() {
+	if engine.SkipMethodNotAllowedMiddleware {
+		engine.allNoMethod = engine.noMethod
+		return
+	}
 	engine.allNoMethod = engine.combineHandlers(engine.noMethod)
 }
 

gin_test.go

@@ -1156,3 +1156,62 @@ func TestUpdateRouteTreesCalledOnce(t *testing.T) {
 		assert.Equal(t, "ok", w.Body.String())
 	}
 }
+
+// Test the fix for https://github.com/gin-gonic/gin/issues/4189
+func TestSkipMethodNotAllowedMiddleware(t *testing.T) {
+	g := New()
+	g.HandleMethodNotAllowed = true
+	g.SkipMethodNotAllowedMiddleware = true
+
+	var middlewareCalled bool
+	middleware := func(c *Context) {
+		middlewareCalled = true
+		c.Next()
+	}
+	noMethodHandler := func(c *Context) {
+		c.String(http.StatusMethodNotAllowed, "method not allowed")
+	}
+
+	g.Use(middleware)
+	g.NoMethod(noMethodHandler)
+	g.POST("/test", func(c *Context) {
+		c.String(http.StatusOK, "ok")
+	})
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/test", nil)
+	g.ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusMethodNotAllowed, w.Code)
+	assert.Equal(t, "method not allowed", w.Body.String())
+	assert.False(t, middlewareCalled, "middleware should not be called when SkipMethodNotAllowedMiddleware is true")
+}
+
+func TestSkipMethodNotAllowedMiddlewareDisabled(t *testing.T) {
+	g := New()
+	g.HandleMethodNotAllowed = true
+	g.SkipMethodNotAllowedMiddleware = false
+
+	var middlewareCalled bool
+	middleware := func(c *Context) {
+		middlewareCalled = true
+		c.Next()
+	}
+	noMethodHandler := func(c *Context) {
+		c.String(http.StatusMethodNotAllowed, "method not allowed")
+	}
+
+	g.Use(middleware)
+	g.NoMethod(noMethodHandler)
+	g.POST("/test", func(c *Context) {
+		c.String(http.StatusOK, "ok")
+	})
+
+	w := httptest.NewRecorder()
+	req, _ := http.NewRequest(http.MethodGet, "/test", nil)
+	g.ServeHTTP(w, req)
+
+	assert.Equal(t, http.StatusMethodNotAllowed, w.Code)
+	assert.Equal(t, "method not allowed", w.Body.String())
+	assert.True(t, middlewareCalled, "middleware should be called when SkipMethodNotAllowedMiddleware is false")
+}