Follow file symlinks in the UI to their target (#28835)

Symlinks are followed when you click on a link next to an entry, either
until a file has been found or until we know that the link is dead.
When the link cannot be accessed, we fall back to the current behavior
of showing the document containing the target.

---------

Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

modules/fileicon/entry.go

@@ -6,17 +6,17 @@ package fileicon
 import "code.gitea.io/gitea/modules/git"
 
 type EntryInfo struct {
-	FullName      string
+	BaseName      string
 	EntryMode     git.EntryMode
 	SymlinkToMode git.EntryMode
 	IsOpen        bool
 }
 
-func EntryInfoFromGitTreeEntry(gitEntry *git.TreeEntry) *EntryInfo {
+func EntryInfoFromGitTreeEntry(commit *git.Commit, fullPath string, gitEntry *git.TreeEntry) *EntryInfo {
-	ret := &EntryInfo{FullName: gitEntry.Name(), EntryMode: gitEntry.Mode()}
+	ret := &EntryInfo{BaseName: gitEntry.Name(), EntryMode: gitEntry.Mode()}
 	if gitEntry.IsLink() {
-		if te, err := gitEntry.FollowLink(); err == nil && te.IsDir() {
+		if res, err := git.EntryFollowLink(commit, fullPath, gitEntry); err == nil && res.TargetEntry.IsDir() {
-			ret.SymlinkToMode = te.Mode()
+			ret.SymlinkToMode = res.TargetEntry.Mode()
 		}
 	}
 	return ret

modules/fileicon/material.go

@@ -5,7 +5,6 @@ package fileicon
 
 import (
 	"html/template"
-	"path"
 	"strings"
 	"sync"
 
@@ -134,7 +133,7 @@ func (m *MaterialIconProvider) FindIconName(entry *EntryInfo) string {
 		return "folder-git"
 	}
 
-	fileNameLower := strings.ToLower(path.Base(entry.FullName))
+	fileNameLower := strings.ToLower(entry.BaseName)
 	if entry.EntryMode.IsDir() {
 		if s, ok := m.rules.FolderNames[fileNameLower]; ok {
 			return s

modules/fileicon/material_test.go

@@ -20,8 +20,8 @@ func TestMain(m *testing.M) {
 func TestFindIconName(t *testing.T) {
 	unittest.PrepareTestEnv(t)
 	p := fileicon.DefaultMaterialIconProvider()
-	assert.Equal(t, "php", p.FindIconName(&fileicon.EntryInfo{FullName: "foo.php", EntryMode: git.EntryModeBlob}))
+	assert.Equal(t, "php", p.FindIconName(&fileicon.EntryInfo{BaseName: "foo.php", EntryMode: git.EntryModeBlob}))
-	assert.Equal(t, "php", p.FindIconName(&fileicon.EntryInfo{FullName: "foo.PHP", EntryMode: git.EntryModeBlob}))
+	assert.Equal(t, "php", p.FindIconName(&fileicon.EntryInfo{BaseName: "foo.PHP", EntryMode: git.EntryModeBlob}))
-	assert.Equal(t, "javascript", p.FindIconName(&fileicon.EntryInfo{FullName: "foo.js", EntryMode: git.EntryModeBlob}))
+	assert.Equal(t, "javascript", p.FindIconName(&fileicon.EntryInfo{BaseName: "foo.js", EntryMode: git.EntryModeBlob}))
-	assert.Equal(t, "visualstudio", p.FindIconName(&fileicon.EntryInfo{FullName: "foo.vba", EntryMode: git.EntryModeBlob}))
+	assert.Equal(t, "visualstudio", p.FindIconName(&fileicon.EntryInfo{BaseName: "foo.vba", EntryMode: git.EntryModeBlob}))
 }

modules/git/commit.go

@@ -20,7 +20,8 @@ import (
 
 // Commit represents a git commit.
 type Commit struct {
-	Tree
+	Tree // FIXME: bad design, this field can be nil if the commit is from "last commit cache"
+
 	ID            ObjectID // The ID of this commit object
 	Author        *Signature
 	Committer     *Signature

modules/git/error.go

@@ -32,22 +32,6 @@ func (err ErrNotExist) Unwrap() error {
 	return util.ErrNotExist
 }
 
-// ErrSymlinkUnresolved entry.FollowLink error
-type ErrSymlinkUnresolved struct {
-	Name    string
-	Message string
-}
-
-func (err ErrSymlinkUnresolved) Error() string {
-	return fmt.Sprintf("%s: %s", err.Name, err.Message)
-}
-
-// IsErrSymlinkUnresolved if some error is ErrSymlinkUnresolved
-func IsErrSymlinkUnresolved(err error) bool {
-	_, ok := err.(ErrSymlinkUnresolved)
-	return ok
-}
-
 // ErrBranchNotExist represents a "BranchNotExist" kind of error.
 type ErrBranchNotExist struct {
 	Name string

modules/git/tree_blob_nogogit.go

@@ -11,7 +11,7 @@ import (
 )
 
 // GetTreeEntryByPath get the tree entries according the sub dir
-func (t *Tree) GetTreeEntryByPath(relpath string) (*TreeEntry, error) {
+func (t *Tree) GetTreeEntryByPath(relpath string) (_ *TreeEntry, err error) {
 	if len(relpath) == 0 {
 		return &TreeEntry{
 			ptree:     t,
@@ -21,27 +21,25 @@ func (t *Tree) GetTreeEntryByPath(relpath string) (*TreeEntry, error) {
 		}, nil
 	}
 
-	// FIXME: This should probably use git cat-file --batch to be a bit more efficient
 	relpath = path.Clean(relpath)
 	parts := strings.Split(relpath, "/")
-	var err error
+
 	tree := t
-	for i, name := range parts {
+	for _, name := range parts[:len(parts)-1] {
-		if i == len(parts)-1 {
+		tree, err = tree.SubTree(name)
-			entries, err := tree.ListEntries()
+		if err != nil {
-			if err != nil {
+			return nil, err
-				return nil, err
+		}
-			}
+	}
-			for _, v := range entries {
+
-				if v.Name() == name {
+	name := parts[len(parts)-1]
-					return v, nil
+	entries, err := tree.ListEntries()
-				}
+	if err != nil {
-			}
+		return nil, err
-		} else {
+	}
-			tree, err = tree.SubTree(name)
+	for _, v := range entries {
-			if err != nil {
+		if v.Name() == name {
-				return nil, err
+			return v, nil
-			}
 		}
 	}
 	return nil, ErrNotExist{"", relpath}

modules/git/tree_entry.go

@@ -5,7 +5,7 @@
 package git
 
 import (
-	"io"
+	"path"
 	"sort"
 	"strings"
 
@@ -24,77 +24,57 @@ func (te *TreeEntry) Type() string {
 	}
 }
 
-// FollowLink returns the entry pointed to by a symlink
+type EntryFollowResult struct {
-func (te *TreeEntry) FollowLink() (*TreeEntry, error) {
+	SymlinkContent string
-	if !te.IsLink() {
+	TargetFullPath string
-		return nil, ErrSymlinkUnresolved{te.Name(), "not a symlink"}
+	TargetEntry    *TreeEntry
-	}
-
-	// read the link
-	r, err := te.Blob().DataAsync()
-	if err != nil {
-		return nil, err
-	}
-	closed := false
-	defer func() {
-		if !closed {
-			_ = r.Close()
-		}
-	}()
-	buf := make([]byte, te.Size())
-	_, err = io.ReadFull(r, buf)
-	if err != nil {
-		return nil, err
-	}
-	_ = r.Close()
-	closed = true
-
-	lnk := string(buf)
-	t := te.ptree
-
-	// traverse up directories
-	for ; t != nil && strings.HasPrefix(lnk, "../"); lnk = lnk[3:] {
-		t = t.ptree
-	}
-
-	if t == nil {
-		return nil, ErrSymlinkUnresolved{te.Name(), "points outside of repo"}
-	}
-
-	target, err := t.GetTreeEntryByPath(lnk)
-	if err != nil {
-		if IsErrNotExist(err) {
-			return nil, ErrSymlinkUnresolved{te.Name(), "broken link"}
-		}
-		return nil, err
-	}
-	return target, nil
 }
 
-// FollowLinks returns the entry ultimately pointed to by a symlink
+func EntryFollowLink(commit *Commit, fullPath string, te *TreeEntry) (*EntryFollowResult, error) {
-func (te *TreeEntry) FollowLinks(optLimit ...int) (*TreeEntry, error) {
 	if !te.IsLink() {
-		return nil, ErrSymlinkUnresolved{te.Name(), "not a symlink"}
+		return nil, util.ErrorWrap(util.ErrUnprocessableContent, "%q is not a symlink", fullPath)
 	}
+
+	// git's filename max length is 4096, hopefully a link won't be longer than multiple of that
+	const maxSymlinkSize = 20 * 4096
+	if te.Blob().Size() > maxSymlinkSize {
+		return nil, util.ErrorWrap(util.ErrUnprocessableContent, "%q content exceeds symlink limit", fullPath)
+	}
+
+	link, err := te.Blob().GetBlobContent(maxSymlinkSize)
+	if err != nil {
+		return nil, err
+	}
+	if strings.HasPrefix(link, "/") {
+		// It's said that absolute path will be stored as is in Git
+		return &EntryFollowResult{SymlinkContent: link}, util.ErrorWrap(util.ErrUnprocessableContent, "%q is an absolute symlink", fullPath)
+	}
+
+	targetFullPath := path.Join(path.Dir(fullPath), link)
+	targetEntry, err := commit.GetTreeEntryByPath(targetFullPath)
+	if err != nil {
+		return &EntryFollowResult{SymlinkContent: link}, err
+	}
+	return &EntryFollowResult{SymlinkContent: link, TargetFullPath: targetFullPath, TargetEntry: targetEntry}, nil
+}
+
+func EntryFollowLinks(commit *Commit, firstFullPath string, firstTreeEntry *TreeEntry, optLimit ...int) (res *EntryFollowResult, err error) {
 	limit := util.OptionalArg(optLimit, 10)
-	entry := te
+	treeEntry, fullPath := firstTreeEntry, firstFullPath
 	for range limit {
-		if !entry.IsLink() {
+		res, err = EntryFollowLink(commit, fullPath, treeEntry)
+		if err != nil {
+			return res, err
+		}
+		treeEntry, fullPath = res.TargetEntry, res.TargetFullPath
+		if !treeEntry.IsLink() {
 			break
 		}
-		next, err := entry.FollowLink()
-		if err != nil {
-			return nil, err
-		}
-		if next.ID == entry.ID {
-			return nil, ErrSymlinkUnresolved{entry.Name(), "recursive link"}
-		}
-		entry = next
 	}
-	if entry.IsLink() {
+	if treeEntry.IsLink() {
-		return nil, ErrSymlinkUnresolved{te.Name(), "too many levels of symbolic links"}
+		return res, util.ErrorWrap(util.ErrUnprocessableContent, "%q has too many links", firstFullPath)
 	}
-	return entry, nil
+	return res, nil
 }
 
 // returns the Tree pointed to by this TreeEntry, or nil if this is not a tree

modules/git/tree_entry_common_test.go

@@ -0,0 +1,76 @@
+// Copyright 2024 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package git
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/modules/util"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestFollowLink(t *testing.T) {
+	r, err := openRepositoryWithDefaultContext("tests/repos/repo1_bare")
+	require.NoError(t, err)
+	defer r.Close()
+
+	commit, err := r.GetCommit("37991dec2c8e592043f47155ce4808d4580f9123")
+	require.NoError(t, err)
+
+	// get the symlink
+	{
+		lnkFullPath := "foo/bar/link_to_hello"
+		lnk, err := commit.Tree.GetTreeEntryByPath("foo/bar/link_to_hello")
+		require.NoError(t, err)
+		assert.True(t, lnk.IsLink())
+
+		// should be able to dereference to target
+		res, err := EntryFollowLink(commit, lnkFullPath, lnk)
+		require.NoError(t, err)
+		assert.Equal(t, "hello", res.TargetEntry.Name())
+		assert.Equal(t, "foo/nar/hello", res.TargetFullPath)
+		assert.False(t, res.TargetEntry.IsLink())
+		assert.Equal(t, "b14df6442ea5a1b382985a6549b85d435376c351", res.TargetEntry.ID.String())
+	}
+
+	{
+		// should error when called on a normal file
+		entry, err := commit.Tree.GetTreeEntryByPath("file1.txt")
+		require.NoError(t, err)
+		res, err := EntryFollowLink(commit, "file1.txt", entry)
+		assert.ErrorIs(t, err, util.ErrUnprocessableContent)
+		assert.Nil(t, res)
+	}
+
+	{
+		// should error for broken links
+		entry, err := commit.Tree.GetTreeEntryByPath("foo/broken_link")
+		require.NoError(t, err)
+		assert.True(t, entry.IsLink())
+		res, err := EntryFollowLink(commit, "foo/broken_link", entry)
+		assert.ErrorIs(t, err, util.ErrNotExist)
+		assert.Equal(t, "nar/broken_link", res.SymlinkContent)
+	}
+
+	{
+		// should error for external links
+		entry, err := commit.Tree.GetTreeEntryByPath("foo/outside_repo")
+		require.NoError(t, err)
+		assert.True(t, entry.IsLink())
+		res, err := EntryFollowLink(commit, "foo/outside_repo", entry)
+		assert.ErrorIs(t, err, util.ErrNotExist)
+		assert.Equal(t, "../../outside_repo", res.SymlinkContent)
+	}
+
+	{
+		// testing fix for short link bug
+		entry, err := commit.Tree.GetTreeEntryByPath("foo/link_short")
+		require.NoError(t, err)
+		res, err := EntryFollowLink(commit, "foo/link_short", entry)
+		assert.ErrorIs(t, err, util.ErrNotExist)
+		assert.Equal(t, "a", res.SymlinkContent)
+	}
+}

modules/git/tree_entry_gogit.go

@@ -19,16 +19,12 @@ type TreeEntry struct {
 	gogitTreeEntry *object.TreeEntry
 	ptree          *Tree
 
-	size     int64
+	size  int64
-	sized    bool
+	sized bool
-	fullName string
 }
 
 // Name returns the name of the entry
 func (te *TreeEntry) Name() string {
-	if te.fullName != "" {
-		return te.fullName
-	}
 	return te.gogitTreeEntry.Name
 }
 
@@ -55,7 +51,7 @@ func (te *TreeEntry) Size() int64 {
 	return te.size
 }
 
-// IsSubModule if the entry is a sub module
+// IsSubModule if the entry is a submodule
 func (te *TreeEntry) IsSubModule() bool {
 	return te.gogitTreeEntry.Mode == filemode.Submodule
 }

modules/git/tree_entry_mode.go

@@ -15,7 +15,7 @@ type EntryMode int
 // one of these.
 const (
 	// EntryModeNoEntry is possible if the file was added or removed in a commit. In the case of
-	// added the base commit will not have the file in its tree so a mode of 0o000000 is used.
+	// when adding the base commit doesn't have the file in its tree, a mode of 0o000000 is used.
 	EntryModeNoEntry EntryMode = 0o000000
 
 	EntryModeBlob    EntryMode = 0o100644
@@ -30,7 +30,7 @@ func (e EntryMode) String() string {
 	return strconv.FormatInt(int64(e), 8)
 }
 
-// IsSubModule if the entry is a sub module
+// IsSubModule if the entry is a submodule
 func (e EntryMode) IsSubModule() bool {
 	return e == EntryModeCommit
 }

modules/git/tree_entry_nogogit.go

@@ -57,7 +57,7 @@ func (te *TreeEntry) Size() int64 {
 	return te.size
 }
 
-// IsSubModule if the entry is a sub module
+// IsSubModule if the entry is a submodule
 func (te *TreeEntry) IsSubModule() bool {
 	return te.entryMode.IsSubModule()
 }

modules/git/tree_entry_test.go

@@ -53,50 +53,3 @@ func TestEntriesCustomSort(t *testing.T) {
 	assert.Equal(t, "bcd", entries[6].Name())
 	assert.Equal(t, "abc", entries[7].Name())
 }
-
-func TestFollowLink(t *testing.T) {
-	r, err := openRepositoryWithDefaultContext("tests/repos/repo1_bare")
-	assert.NoError(t, err)
-	defer r.Close()
-
-	commit, err := r.GetCommit("37991dec2c8e592043f47155ce4808d4580f9123")
-	assert.NoError(t, err)
-
-	// get the symlink
-	lnk, err := commit.Tree.GetTreeEntryByPath("foo/bar/link_to_hello")
-	assert.NoError(t, err)
-	assert.True(t, lnk.IsLink())
-
-	// should be able to dereference to target
-	target, err := lnk.FollowLink()
-	assert.NoError(t, err)
-	assert.Equal(t, "hello", target.Name())
-	assert.False(t, target.IsLink())
-	assert.Equal(t, "b14df6442ea5a1b382985a6549b85d435376c351", target.ID.String())
-
-	// should error when called on normal file
-	target, err = commit.Tree.GetTreeEntryByPath("file1.txt")
-	assert.NoError(t, err)
-	_, err = target.FollowLink()
-	assert.EqualError(t, err, "file1.txt: not a symlink")
-
-	// should error for broken links
-	target, err = commit.Tree.GetTreeEntryByPath("foo/broken_link")
-	assert.NoError(t, err)
-	assert.True(t, target.IsLink())
-	_, err = target.FollowLink()
-	assert.EqualError(t, err, "broken_link: broken link")
-
-	// should error for external links
-	target, err = commit.Tree.GetTreeEntryByPath("foo/outside_repo")
-	assert.NoError(t, err)
-	assert.True(t, target.IsLink())
-	_, err = target.FollowLink()
-	assert.EqualError(t, err, "outside_repo: points outside of repo")
-
-	// testing fix for short link bug
-	target, err = commit.Tree.GetTreeEntryByPath("foo/link_short")
-	assert.NoError(t, err)
-	_, err = target.FollowLink()
-	assert.EqualError(t, err, "link_short: broken link")
-}

modules/git/tree_gogit.go

@@ -69,7 +69,7 @@ func (t *Tree) ListEntriesRecursiveWithSize() (Entries, error) {
 	seen := map[plumbing.Hash]bool{}
 	walker := object.NewTreeWalker(t.gogitTree, true, seen)
 	for {
-		fullName, entry, err := walker.Next()
+		_, entry, err := walker.Next()
 		if err == io.EOF {
 			break
 		}
@@ -84,7 +84,6 @@ func (t *Tree) ListEntriesRecursiveWithSize() (Entries, error) {
 			ID:             ParseGogitHash(entry.Hash),
 			gogitTreeEntry: &entry,
 			ptree:          t,
-			fullName:       fullName,
 		}
 		entries = append(entries, convertedEntry)
 	}

modules/util/error.go

@@ -17,8 +17,8 @@ var (
 	ErrNotExist         = errors.New("resource does not exist") // also implies HTTP 404
 	ErrAlreadyExist     = errors.New("resource already exists") // also implies HTTP 409
 
-	// ErrUnprocessableContent implies HTTP 422, syntax of the request content was correct,
+	// ErrUnprocessableContent implies HTTP 422, the syntax of the request content is correct,
-	// but server was unable to process the contained instructions
+	// but the server is unable to process the contained instructions
 	ErrUnprocessableContent = errors.New("unprocessable content")
 )
 

options/locale/locale_en-US.ini

@@ -2782,6 +2782,7 @@ topic.done = Done
 topic.count_prompt = You cannot select more than 25 topics
 topic.format_prompt = Topics must start with a letter or number, can include dashes ('-') and dots ('.'), can be up to 35 characters long. Letters must be lowercase.
 
+find_file.follow_symlink= Follow this symlink to where it is pointing at
 find_file.go_to_file = Go to file
 find_file.no_matching = No matching file found
 

routers/web/repo/treelist.go

@@ -6,6 +6,7 @@ package repo
 import (
 	"html/template"
 	"net/http"
+	"path"
 	"strings"
 
 	pull_model "code.gitea.io/gitea/models/pull"
@@ -111,7 +112,7 @@ func transformDiffTreeForWeb(renderedIconPool *fileicon.RenderedIconPool, diffTr
 		item := &WebDiffFileItem{FullName: file.HeadPath, DiffStatus: file.Status}
 		item.IsViewed = filesViewedState[item.FullName] == pull_model.Viewed
 		item.NameHash = git.HashFilePathForWebUI(item.FullName)
-		item.FileIcon = fileicon.RenderEntryIconHTML(renderedIconPool, &fileicon.EntryInfo{FullName: file.HeadPath, EntryMode: file.HeadMode})
+		item.FileIcon = fileicon.RenderEntryIconHTML(renderedIconPool, &fileicon.EntryInfo{BaseName: path.Base(file.HeadPath), EntryMode: file.HeadMode})
 
 		switch file.HeadMode {
 		case git.EntryModeTree:

routers/web/repo/view.go

@@ -12,6 +12,7 @@ import (
 	"io"
 	"net/http"
 	"net/url"
+	"path"
 	"strings"
 	"time"
 
@@ -260,7 +261,9 @@ func prepareDirectoryFileIcons(ctx *context.Context, files []git.CommitInfo) {
 	renderedIconPool := fileicon.NewRenderedIconPool()
 	fileIcons := map[string]template.HTML{}
 	for _, f := range files {
-		fileIcons[f.Entry.Name()] = fileicon.RenderEntryIconHTML(renderedIconPool, fileicon.EntryInfoFromGitTreeEntry(f.Entry))
+		fullPath := path.Join(ctx.Repo.TreePath, f.Entry.Name())
+		entryInfo := fileicon.EntryInfoFromGitTreeEntry(ctx.Repo.Commit, fullPath, f.Entry)
+		fileIcons[f.Entry.Name()] = fileicon.RenderEntryIconHTML(renderedIconPool, entryInfo)
 	}
 	fileIcons[".."] = fileicon.RenderEntryIconHTML(renderedIconPool, fileicon.EntryInfoFolder())
 	ctx.Data["FileIcons"] = fileIcons

routers/web/repo/view_home.go

@@ -143,7 +143,7 @@ func prepareToRenderDirectory(ctx *context.Context) {
 		ctx.Data["Title"] = ctx.Tr("repo.file.title", ctx.Repo.Repository.Name+"/"+path.Base(ctx.Repo.TreePath), ctx.Repo.RefFullName.ShortName())
 	}
 
-	subfolder, readmeFile, err := findReadmeFileInEntries(ctx, entries, true)
+	subfolder, readmeFile, err := findReadmeFileInEntries(ctx, ctx.Repo.TreePath, entries, true)
 	if err != nil {
 		ctx.ServerError("findReadmeFileInEntries", err)
 		return
@@ -377,8 +377,8 @@ func prepareHomeTreeSideBarSwitch(ctx *context.Context) {
 
 func redirectSrcToRaw(ctx *context.Context) bool {
 	// GitHub redirects a tree path with "?raw=1" to the raw path
-	// It is useful to embed some raw contents into markdown files,
+	// It is useful to embed some raw contents into Markdown files,
-	// then viewing the markdown in "src" path could embed the raw content correctly.
+	// then viewing the Markdown in "src" path could embed the raw content correctly.
 	if ctx.Repo.TreePath != "" && ctx.FormBool("raw") {
 		ctx.Redirect(ctx.Repo.RepoLink + "/raw/" + ctx.Repo.RefTypeNameSubURL() + "/" + util.PathEscapeSegments(ctx.Repo.TreePath))
 		return true
@@ -386,6 +386,20 @@ func redirectSrcToRaw(ctx *context.Context) bool {
 	return false
 }
 
+func redirectFollowSymlink(ctx *context.Context, treePathEntry *git.TreeEntry) bool {
+	if ctx.Repo.TreePath == "" || !ctx.FormBool("follow_symlink") {
+		return false
+	}
+	if treePathEntry.IsLink() {
+		if res, err := git.EntryFollowLinks(ctx.Repo.Commit, ctx.Repo.TreePath, treePathEntry); err == nil {
+			redirect := ctx.Repo.RepoLink + "/src/" + ctx.Repo.RefTypeNameSubURL() + "/" + util.PathEscapeSegments(res.TargetFullPath) + "?" + ctx.Req.URL.RawQuery
+			ctx.Redirect(redirect)
+			return true
+		} // else: don't handle the links we cannot resolve, so ignore the error
+	}
+	return false
+}
+
 // Home render repository home page
 func Home(ctx *context.Context) {
 	if handleRepoHomeFeed(ctx) {
@@ -394,6 +408,7 @@ func Home(ctx *context.Context) {
 	if redirectSrcToRaw(ctx) {
 		return
 	}
+
 	// Check whether the repo is viewable: not in migration, and the code unit should be enabled
 	// Ideally the "feed" logic should be after this, but old code did so, so keep it as-is.
 	checkHomeCodeViewable(ctx)
@@ -424,6 +439,10 @@ func Home(ctx *context.Context) {
 		return
 	}
 
+	if redirectFollowSymlink(ctx, entry) {
+		return
+	}
+
 	// prepare the tree path
 	var treeNames, paths []string
 	branchLink := ctx.Repo.RepoLink + "/src/" + ctx.Repo.RefTypeNameSubURL()

routers/web/repo/view_readme.go

@@ -32,15 +32,7 @@ import (
 //	entries == ctx.Repo.Commit.SubTree(ctx.Repo.TreePath).ListEntries()
 //
 // FIXME: There has to be a more efficient way of doing this
-func findReadmeFileInEntries(ctx *context.Context, entries []*git.TreeEntry, tryWellKnownDirs bool) (string, *git.TreeEntry, error) {
+func findReadmeFileInEntries(ctx *context.Context, parentDir string, entries []*git.TreeEntry, tryWellKnownDirs bool) (string, *git.TreeEntry, error) {
-	// Create a list of extensions in priority order
-	// 1. Markdown files - with and without localisation - e.g. README.en-us.md or README.md
-	// 2. Txt files - e.g. README.txt
-	// 3. No extension - e.g. README
-	exts := append(localizedExtensions(".md", ctx.Locale.Language()), ".txt", "") // sorted by priority
-	extCount := len(exts)
-	readmeFiles := make([]*git.TreeEntry, extCount+1)
-
 	docsEntries := make([]*git.TreeEntry, 3) // (one of docs/, .gitea/ or .github/)
 	for _, entry := range entries {
 		if tryWellKnownDirs && entry.IsDir() {
@@ -62,16 +54,23 @@ func findReadmeFileInEntries(ctx *context.Context, entries []*git.TreeEntry, try
 					docsEntries[2] = entry
 				}
 			}
-			continue
 		}
+	}
+
+	// Create a list of extensions in priority order
+	// 1. Markdown files - with and without localisation - e.g. README.en-us.md or README.md
+	// 2. Txt files - e.g. README.txt
+	// 3. No extension - e.g. README
+	exts := append(localizedExtensions(".md", ctx.Locale.Language()), ".txt", "") // sorted by priority
+	extCount := len(exts)
+	readmeFiles := make([]*git.TreeEntry, extCount+1)
+	for _, entry := range entries {
 		if i, ok := util.IsReadmeFileExtension(entry.Name(), exts...); ok {
-			log.Debug("Potential readme file: %s", entry.Name())
+			fullPath := path.Join(parentDir, entry.Name())
 			if readmeFiles[i] == nil || base.NaturalSortLess(readmeFiles[i].Name(), entry.Blob().Name()) {
 				if entry.IsLink() {
-					target, err := entry.FollowLinks()
+					res, err := git.EntryFollowLinks(ctx.Repo.Commit, fullPath, entry)
-					if err != nil && !git.IsErrSymlinkUnresolved(err) {
+					if err == nil && (res.TargetEntry.IsExecutable() || res.TargetEntry.IsRegular()) {
-						return "", nil, err
-					} else if target != nil && (target.IsExecutable() || target.IsRegular()) {
 						readmeFiles[i] = entry
 					}
 				} else {
@@ -80,6 +79,7 @@ func findReadmeFileInEntries(ctx *context.Context, entries []*git.TreeEntry, try
 			}
 		}
 	}
+
 	var readmeFile *git.TreeEntry
 	for _, f := range readmeFiles {
 		if f != nil {
@@ -103,7 +103,7 @@ func findReadmeFileInEntries(ctx *context.Context, entries []*git.TreeEntry, try
 				return "", nil, err
 			}
 
-			subfolder, readmeFile, err := findReadmeFileInEntries(ctx, childEntries, false)
+			subfolder, readmeFile, err := findReadmeFileInEntries(ctx, parentDir, childEntries, false)
 			if err != nil && !git.IsErrNotExist(err) {
 				return "", nil, err
 			}
@@ -139,22 +139,29 @@ func localizedExtensions(ext, languageCode string) (localizedExts []string) {
 }
 
 func prepareToRenderReadmeFile(ctx *context.Context, subfolder string, readmeFile *git.TreeEntry) {
-	target := readmeFile
+	if readmeFile == nil {
-	if readmeFile != nil && readmeFile.IsLink() {
-		target, _ = readmeFile.FollowLinks()
-	}
-	if target == nil {
-		// if findReadmeFile() failed and/or gave us a broken symlink (which it shouldn't)
-		// simply skip rendering the README
 		return
 	}
 
+	readmeFullPath := path.Join(ctx.Repo.TreePath, subfolder, readmeFile.Name())
+	readmeTargetEntry := readmeFile
+	if readmeFile.IsLink() {
+		if res, err := git.EntryFollowLinks(ctx.Repo.Commit, readmeFullPath, readmeFile); err == nil {
+			readmeTargetEntry = res.TargetEntry
+		} else {
+			readmeTargetEntry = nil // if we cannot resolve the symlink, we cannot render the readme, ignore the error
+		}
+	}
+	if readmeTargetEntry == nil {
+		return // if no valid README entry found, skip rendering the README
+	}
+
 	ctx.Data["RawFileLink"] = ""
 	ctx.Data["ReadmeInList"] = path.Join(subfolder, readmeFile.Name()) // the relative path to the readme file to the current tree path
 	ctx.Data["ReadmeExist"] = true
 	ctx.Data["FileIsSymlink"] = readmeFile.IsLink()
 
-	buf, dataRc, fInfo, err := getFileReader(ctx, ctx.Repo.Repository.ID, target.Blob())
+	buf, dataRc, fInfo, err := getFileReader(ctx, ctx.Repo.Repository.ID, readmeTargetEntry.Blob())
 	if err != nil {
 		ctx.ServerError("getFileReader", err)
 		return
@@ -162,7 +169,7 @@ func prepareToRenderReadmeFile(ctx *context.Context, subfolder string, readmeFil
 	defer dataRc.Close()
 
 	ctx.Data["FileIsText"] = fInfo.st.IsText()
-	ctx.Data["FileTreePath"] = path.Join(ctx.Repo.TreePath, subfolder, readmeFile.Name())
+	ctx.Data["FileTreePath"] = readmeFullPath
 	ctx.Data["FileSize"] = fInfo.fileSize
 	ctx.Data["IsLFSFile"] = fInfo.isLFSFile()
 
@@ -189,10 +196,10 @@ func prepareToRenderReadmeFile(ctx *context.Context, subfolder string, readmeFil
 
 		rctx := renderhelper.NewRenderContextRepoFile(ctx, ctx.Repo.Repository, renderhelper.RepoFileOptions{
 			CurrentRefPath:  ctx.Repo.RefTypeNameSubURL(),
-			CurrentTreePath: path.Join(ctx.Repo.TreePath, subfolder),
+			CurrentTreePath: path.Dir(readmeFullPath),
 		}).
 			WithMarkupType(markupType).
-			WithRelativePath(path.Join(ctx.Repo.TreePath, subfolder, readmeFile.Name())) // ctx.Repo.TreePath is the directory not the Readme so we must append the Readme filename (and path).
+			WithRelativePath(readmeFullPath)
 
 		ctx.Data["EscapeStatus"], ctx.Data["FileContent"], err = markupRender(ctx, rctx, rd)
 		if err != nil {

services/repository/files/tree.go

@@ -161,7 +161,7 @@ func newTreeViewNodeFromEntry(ctx context.Context, renderedIconPool *fileicon.Re
 		FullPath:  path.Join(parentDir, entry.Name()),
 	}
 
-	entryInfo := fileicon.EntryInfoFromGitTreeEntry(entry)
+	entryInfo := fileicon.EntryInfoFromGitTreeEntry(commit, node.FullPath, entry)
 	node.EntryIcon = fileicon.RenderEntryIconHTML(renderedIconPool, entryInfo)
 	if entryInfo.EntryMode.IsDir() {
 		entryInfo.IsOpen = true

templates/repo/view_list.tmpl

@@ -41,6 +41,9 @@
 						</a>
 					{{else}}
 						<a class="entry-name" href="{{$.TreeLink}}/{{PathEscapeSegments $entry.Name}}" title="{{$entry.Name}}">{{$entry.Name}}</a>
+						{{if $entry.IsLink}}
+							<a class="entry-symbol-link flex-text-inline" data-tooltip-content title="{{ctx.Locale.Tr "repo.find_file.follow_symlink"}}" href="{{$.TreeLink}}/{{PathEscapeSegments $entry.Name}}?follow_symlink=1">{{svg "octicon-link" 12}}</a>
+						{{end}}
 					{{end}}
 				{{end}}
 			</div>

tests/integration/repo_test.go

@@ -27,6 +27,7 @@ import (
 
 	"github.com/PuerkitoBio/goquery"
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 )
 
 func TestRepoView(t *testing.T) {
@@ -41,6 +42,7 @@ func TestRepoView(t *testing.T) {
 	t.Run("BlameFileInRepo", testBlameFileInRepo)
 	t.Run("ViewRepoDirectory", testViewRepoDirectory)
 	t.Run("ViewRepoDirectoryReadme", testViewRepoDirectoryReadme)
+	t.Run("ViewRepoSymlink", testViewRepoSymlink)
 	t.Run("MarkDownReadmeImage", testMarkDownReadmeImage)
 	t.Run("MarkDownReadmeImageSubfolder", testMarkDownReadmeImageSubfolder)
 	t.Run("GeneratedSourceLink", testGeneratedSourceLink)
@@ -412,6 +414,21 @@ func testViewRepoDirectoryReadme(t *testing.T) {
 	missing("symlink-loop", "/user2/readme-test/src/branch/symlink-loop/")
 }
 
+func testViewRepoSymlink(t *testing.T) {
+	session := loginUser(t, "user2")
+	req := NewRequest(t, "GET", "/user2/readme-test/src/branch/symlink")
+	resp := session.MakeRequest(t, req, http.StatusOK)
+
+	htmlDoc := NewHTMLParser(t, resp.Body)
+	AssertHTMLElement(t, htmlDoc, ".entry-symbol-link", true)
+	followSymbolLinkHref := htmlDoc.Find(".entry-symbol-link").AttrOr("href", "")
+	require.Equal(t, "/user2/readme-test/src/branch/symlink/README.md?follow_symlink=1", followSymbolLinkHref)
+
+	req = NewRequest(t, "GET", followSymbolLinkHref)
+	resp = session.MakeRequest(t, req, http.StatusSeeOther)
+	assert.Equal(t, "/user2/readme-test/src/branch/symlink/some/other/path/awefulcake.txt?follow_symlink=1", resp.Header().Get("Location"))
+}
+
 func testMarkDownReadmeImage(t *testing.T) {
 	defer tests.PrintCurrentTest(t)()