Fix #1493 router loop for param routes (#1501)

* Add test to reproduce router loop for #1493

* Simplify and correct  router param tests

* Fix #1493 to avoid router loop for param nodes

router.go

@@ -376,8 +376,8 @@ func (r *Router) Find(method, path string, c Context) {
 			continue
 		}
 
-		// Param node
 	Param:
+		// Param node
 		if child = cn.findChildByKind(pkind); child != nil {
 			// Issue #378
 			if len(pvalues) == n {
@@ -401,24 +401,37 @@ func (r *Router) Find(method, path string, c Context) {
 			continue
 		}
 
-		// Any node
 	Any:
-		if cn = cn.findChildByKind(akind); cn == nil {
+		// Any node
+		if cn = cn.findChildByKind(akind); cn != nil {
+			// If any node is found, use remaining path for pvalues
+			pvalues[len(cn.pnames)-1] = search
+			break
+		}
+
+		// No node found, continue at stored next node
+		// or find nearest "any" route
 		if nn != nil {
 			// No next node to go down in routing (issue #954)
 			// Find nearest "any" route going up the routing tree
 			search = ns
 			np := nn.parent
 			// Consider param route one level up only
-				// if no slash is remaining in search string
+			if cn = nn.findChildByKind(pkind); cn != nil {
-				if cn = nn.findChildByKind(pkind); cn != nil && strings.IndexByte(ns, '/') == -1 {
+				pos := strings.IndexByte(ns, '/')
+				if pos == -1 {
+					// If no slash is remaining in search string set param value
 					pvalues[len(cn.pnames)-1] = search
 					break
-				} else if cn != nil && strings.IndexByte(ns, '/') != 1 {
+				} else if pos > 0 {
-					// If slash is present, it means that this is a parameterized route.
+					// Otherwise continue route processing with restored next node
-					cn = cn.parent
+					cn = nn
+					nn = nil
+					ns = ""
 					goto Param
 				}
+			}
+			// No param route found, try to resolve nearest any route
 			for {
 				np = nn.parent
 				if cn = nn.findChildByKind(akind); cn != nil {
@@ -439,9 +452,7 @@ func (r *Router) Find(method, path string, c Context) {
 			}
 		}
 		return // Not found
-		}
+
-		pvalues[len(cn.pnames)-1] = search
-		break
 	}
 
 	ctx.handler = cn.findHandler(method)

router_test.go

@@ -1031,12 +1031,15 @@ func TestRouterParamBacktraceNotFound(t *testing.T) {
 	r.Find(http.MethodGet, "/a", c)
 	assert.Equal(t, "a", c.Param("param1"))
 
+	c = e.NewContext(nil, nil).(*context)
 	r.Find(http.MethodGet, "/a/foo", c)
 	assert.Equal(t, "a", c.Param("param1"))
 
+	c = e.NewContext(nil, nil).(*context)
 	r.Find(http.MethodGet, "/a/bar", c)
 	assert.Equal(t, "a", c.Param("param1"))
 
+	c = e.NewContext(nil, nil).(*context)
 	r.Find(http.MethodGet, "/a/bar/b", c)
 	assert.Equal(t, "a", c.Param("param1"))
 	assert.Equal(t, "b", c.Param("param2"))
@@ -1157,31 +1160,45 @@ func TestRouterParam1466(t *testing.T) {
 	r.Find(http.MethodGet, "/users/ajitem", c)
 	assert.Equal(t, "ajitem", c.Param("username"))
 
+	c = e.NewContext(nil, nil).(*context)
 	r.Find(http.MethodGet, "/users/sharewithme", c)
 	assert.Equal(t, "sharewithme", c.Param("username"))
 
+	c = e.NewContext(nil, nil).(*context)
 	r.Find(http.MethodGet, "/users/signup", c)
 	assert.Equal(t, "", c.Param("username"))
 	// Additional assertions for #1479
+	c = e.NewContext(nil, nil).(*context)
 	r.Find(http.MethodGet, "/users/sharewithme/likes/projects/ids", c)
 	assert.Equal(t, "sharewithme", c.Param("username"))
 
+	c = e.NewContext(nil, nil).(*context)
 	r.Find(http.MethodGet, "/users/ajitem/likes/projects/ids", c)
 	assert.Equal(t, "ajitem", c.Param("username"))
 
+	c = e.NewContext(nil, nil).(*context)
 	r.Find(http.MethodGet, "/users/sharewithme/profile", c)
 	assert.Equal(t, "sharewithme", c.Param("username"))
 
+	c = e.NewContext(nil, nil).(*context)
 	r.Find(http.MethodGet, "/users/ajitem/profile", c)
 	assert.Equal(t, "ajitem", c.Param("username"))
 
+	c = e.NewContext(nil, nil).(*context)
 	r.Find(http.MethodGet, "/users/sharewithme/uploads/self", c)
 	assert.Equal(t, "sharewithme", c.Param("username"))
 	assert.Equal(t, "self", c.Param("type"))
 
+	c = e.NewContext(nil, nil).(*context)
 	r.Find(http.MethodGet, "/users/ajitem/uploads/self", c)
 	assert.Equal(t, "ajitem", c.Param("username"))
 	assert.Equal(t, "self", c.Param("type"))
+
+	// Issue #1493 - check for routing loop
+	c = e.NewContext(nil, nil).(*context)
+	r.Find(http.MethodGet, "/users/tree/free", c)
+	assert.Equal(t, "", c.Param("id"))
+	assert.Equal(t, 0, c.response.Status)
 }
 
 func benchmarkRouterRoutes(b *testing.B, routes []*Route) {