Fix issue with middleware from one route leaking into the middleware of other routes

Fixed #565

Signed-off-by: Vishal Rana <vr@labstack.com>

echo.go

@@ -476,7 +476,6 @@ func (e *Echo) add(method, path string, handler HandlerFunc, middleware ...Middl
 		Handler: name,
 	}
 	e.router.routes[method+path] = r
-	// e.router.routes = append(e.router.routes, r)
 }
 
 // Group creates a new router group with prefix and optional group-level middleware.

group.go

@@ -126,8 +126,10 @@ func (g *Group) Match(methods []string, path string, handler HandlerFunc, middle
 }
 
 // Group creates a new sub-group with prefix and optional sub-group-level middleware.
-func (g *Group) Group(prefix string, m ...MiddlewareFunc) *Group {
-	m = append(g.middleware, m...)
+func (g *Group) Group(prefix string, middleware ...MiddlewareFunc) *Group {
+	m := []MiddlewareFunc{}
+	m = append(m, g.middleware...)
+	m = append(m, middleware...)
 	return g.echo.Group(g.prefix+prefix, m...)
 }
 
@@ -142,6 +144,11 @@ func (g *Group) File(path, file string) {
 }
 
 func (g *Group) add(method, path string, handler HandlerFunc, middleware ...MiddlewareFunc) {
-	middleware = append(g.middleware, middleware...)
-	g.echo.add(method, g.prefix+path, handler, middleware...)
+	// Combine into a new slice, to avoid accidentally passing the same
+	// slice for multiple routes, which would lead to later add() calls overwriting
+	// the middleware from earlier calls
+	m := []MiddlewareFunc{}
+	m = append(m, g.middleware...)
+	m = append(m, middleware...)
+	g.echo.add(method, g.prefix+path, handler, m...)
 }

group_test.go

@@ -1,6 +1,9 @@
 package echo
 
-import "testing"
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
 
 // TODO: Fix me
 func TestGroup(t *testing.T) {
@@ -29,3 +32,23 @@ func TestGroup(t *testing.T) {
 	g.Static("/static", "/tmp")
 	g.File("/walle", "_fixture/images//walle.png")
 }
+
+func TestGroupRouteMiddleware(t *testing.T) {
+	// Ensure middleware slices are not re-used
+	e := New()
+	g := e.Group("/group")
+	h := func(Context) error { return nil }
+	m1 := WrapMiddleware(func(c Context) error { return nil })
+	m2 := WrapMiddleware(func(c Context) error { return nil })
+	m3 := WrapMiddleware(func(c Context) error { return nil })
+	m4 := WrapMiddleware(func(c Context) error { return c.NoContent(404) })
+	m5 := WrapMiddleware(func(c Context) error { return c.NoContent(405) })
+	g.Use(m1, m2, m3)
+	g.GET("/404", h, m4)
+	g.GET("/405", h, m5)
+
+	c, _ := request(GET, "/group/404", e)
+	assert.Equal(t, 404, c)
+	c, _ = request(GET, "/group/405", e)
+	assert.Equal(t, 405, c)
+}