move redirect handler to repo, escape params, and add unit tests

Author: bohde

routers/web/repo/view_home.go

@@ -8,6 +8,7 @@ import (
 	"fmt"
 	"html/template"
 	"net/http"
+	"net/url"
 	"path"
 	"strings"
 	"time"
@@ -412,3 +413,32 @@ func Home(ctx *context.Context) {
 
 	ctx.HTML(http.StatusOK, tplRepoHome)
 }
+
+// HomeRedirect redirects from /tree/* to /src/* in order to maintain a similar URL structure.
+func HomeRedirect(ctx *context.Context) {
+	prefix := "/"
+	if setting.AppSubURL != "" {
+		prefix = setting.AppSubURL
+	}
+
+	url := treeRedirectURL(
+		prefix,
+		ctx.PathParam("username"),
+		ctx.PathParam("reponame"),
+		ctx.PathParam("*"),
+	)
+	ctx.Redirect(url)
+}
+
+// treeRedirectURL constructs a "src" URL from the given "tree"
+// prefixed path params. This is a private function for testing
+// purposes.
+func treeRedirectURL(prefix, username, reponame, remainder string) string {
+	return path.Join(
+		prefix,
+		url.PathEscape(username),
+		url.PathEscape(reponame),
+		"src",
+		util.PathEscapeSegments(remainder),
+	)
+}

routers/web/repo/view_home_test.go

@@ -0,0 +1,50 @@
+// Copyright 2025 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package repo
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestTreeRedirectURL(t *testing.T) {
+	type testcase struct {
+		name                                  string
+		prefix, username, reponame, remainder string
+		expected                              string
+	}
+
+	cases := []testcase{
+		{
+			name:   "ref",
+			prefix: "/", username: "user2", reponame: "readme-test", remainder: "main",
+			expected: "/user2/readme-test/src/main",
+		},
+		{
+			name:   "sha",
+			prefix: "/", username: "user2", reponame: "readme-test", remainder: "fe495ea336f079ef2bed68648d0ba9a37cdbd4aa",
+			expected: "/user2/readme-test/src/fe495ea336f079ef2bed68648d0ba9a37cdbd4aa",
+		},
+		{
+			name:   "escape",
+			prefix: "/", username: "user/2%", reponame: "readme/test?", remainder: "$/&",
+			expected: "/user%2F2%25/readme%2Ftest%3F/src/$/&",
+		},
+		{
+			name:   "appPath",
+			prefix: "/app-path", username: "user2", reponame: "readme-test", remainder: "main",
+			expected: "/app-path/user2/readme-test/src/main",
+		},
+	}
+
+	for _, c := range cases {
+		c := c
+		t.Run(c.name, func(t *testing.T) {
+			actual := treeRedirectURL(c.prefix, c.username, c.reponame, c.remainder)
+			assert.Equal(t, c.expected, actual)
+		})
+	}
+
+}

routers/web/web.go

@@ -5,7 +5,6 @@ package web
 
 import (
 	"net/http"
-	"path"
 	"strings"
 
 	auth_model "code.gitea.io/gitea/models/auth"
@@ -1587,15 +1586,7 @@ func registerRoutes(m *web.Router) {
 
 		// Add a /tree/* path to redirect to the deprecated /src/*
 		// path. This emulates both Github & Gitlab's URL structure.
-		m.Get("/tree/*", func(ctx *context.Context) {
-			prefix := "/"
-			if setting.AppSubURL != "" {
-				prefix = setting.AppSubURL
-			}
-
-			url := path.Join(prefix, ctx.PathParam("username"), ctx.PathParam("reponame"), "src", ctx.PathParam("*"))
-			ctx.Redirect(url)
-		})
+		m.Get("/tree/*", repo.HomeRedirect)
 
 		m.Get("/forks", context.RepoRef(), repo.Forks)
 		m.Get("/commit/{sha:([a-f0-9]{7,64})}.{ext:patch|diff}", repo.MustBeNotEmpty, repo.RawDiff)