From f9e97332f3bebd2c26753f7dc679588a22cb387d Mon Sep 17 00:00:00 2001
From: Vishal Rana <vr@labstack.com>
Date: Tue, 15 Nov 2016 20:09:52 -0800
Subject: [PATCH] fixed #729

Signed-off-by: Vishal Rana <vr@labstack.com>
---
 router.go      |  5 ++++-
 router_test.go | 47 ++++++++++++++++++++++++++++++-----------------
 2 files changed, 34 insertions(+), 18 deletions(-)

diff --git a/router.go b/router.go
index 83895a45..b53edb5a 100644
--- a/router.go
+++ b/router.go
@@ -172,7 +172,10 @@ func (r *Router) insert(method, path string, h HandlerFunc, t kind, ppath string
 			if h != nil {
 				cn.addHandler(method, h)
 				cn.ppath = ppath
-				for i, n := range cn.pnames {
+				if len(cn.pnames) == 0 { // Issue #729
+					cn.pnames = pnames
+				}
+				for i, n := range pnames {
 					// Param name aliases
 					if !strings.Contains(n, pnames[i]) {
 						cn.pnames[i] += "," + pnames[i]
diff --git a/router_test.go b/router_test.go
index 968c8dde..ee48f951 100644
--- a/router_test.go
+++ b/router_test.go
@@ -812,29 +812,42 @@ func TestRouterStaticDynamicConflict(t *testing.T) {
 	assert.Equal(t, 3, c.Get("c"))
 }
 
-func TestRouterAPI(t *testing.T) {
+func testRouterAPI(t *testing.T, api []Route) {
 	e := New()
 	r := e.router
 
-	for _, route := range gitHubAPI {
+	for _, route := range api {
 		r.Add(route.Method, route.Path, func(c Context) error {
 			return nil
 		})
 	}
 	c := e.NewContext(nil, nil).(*context)
-	for _, route := range gitHubAPI {
+	for _, route := range api {
 		r.Find(route.Method, route.Path, c)
-		for _, n := range c.pnames {
-			for _, p := range strings.Split(n, ",") {
-				if assert.NotEmpty(t, p) {
-					assert.Equal(t, c.Param(p), ":"+p)
-				}
+		tokens := strings.Split(route.Path[1:], "/")
+		for _, token := range tokens {
+			if token[0] == ':' {
+				assert.Equal(t, c.Param(token[1:]), token)
 			}
 		}
 	}
 }
 
-func benchmarkRoutes(b *testing.B, routes []Route) {
+func TestRouterGitHubAPI(t *testing.T) {
+	testRouterAPI(t, gitHubAPI)
+}
+
+// Issue #729
+func TestRouterParamAlias(t *testing.T) {
+	api := []Route{
+		{GET, "/users/:userID/following", ""},
+		{GET, "/users/:userID/followedBy", ""},
+		{GET, "/users/:userID/follow", ""},
+	}
+	testRouterAPI(t, api)
+}
+
+func benchmarkRouterRoutes(b *testing.B, routes []Route) {
 	e := New()
 	r := e.router
 	b.ReportAllocs()
@@ -856,20 +869,20 @@ func benchmarkRoutes(b *testing.B, routes []Route) {
 	}
 }
 
-func BenchmarkStaticRoute(b *testing.B) {
-	benchmarkRoutes(b, staticRoutes)
+func BenchmarkRouterStaticRoutes(b *testing.B) {
+	benchmarkRouterRoutes(b, staticRoutes)
 }
 
-func BenchmarkGitHubAPI(b *testing.B) {
-	benchmarkRoutes(b, gitHubAPI)
+func BenchmarkRouterGitHubAPI(b *testing.B) {
+	benchmarkRouterRoutes(b, gitHubAPI)
 }
 
-func BenchmarkParseAPI(b *testing.B) {
-	benchmarkRoutes(b, parseAPI)
+func BenchmarkRouterParseAPI(b *testing.B) {
+	benchmarkRouterRoutes(b, parseAPI)
 }
 
-func BenchmarkGooglePlusAPI(b *testing.B) {
-	benchmarkRoutes(b, googlePlusAPI)
+func BenchmarkRouterGooglePlusAPI(b *testing.B) {
+	benchmarkRouterRoutes(b, googlePlusAPI)
 }
 
 func (n *node) printTree(pfx string, tail bool) {