Added walking through dereferenced symlink dir

Signed-off-by: Jakub Wójtowicz <jakub.wojtowic@gmail.com>

Author: sephriot

archives.go

@@ -100,10 +100,20 @@ func FilesFromDisk(ctx context.Context, options *FromDiskOptions, filenames map[
 var linkTarget string
 if isSymlink(info) {
 if options != nil && options.FollowSymlinks {
+originalFilename := filename
 filename, info, err = followSymlink(filename)
 if err != nil {
 return err
 }
+if info.IsDir() {
+symlinkDirFiles, err := FilesFromDisk(ctx, options, map[string]string{filename: nameInArchive})
+if err != nil {
+return fmt.Errorf("getting files from symlink directory %s dereferenced to %s: %w", originalFilename, linkTarget, err)
+}
+
+files = append(files, symlinkDirFiles...)
+return nil
+}
 } else {
 // preserve symlinks
 linkTarget, err = os.Readlink(filename)
@@ -128,6 +138,7 @@ func FilesFromDisk(ctx context.Context, options *FromDiskOptions, filenames map[
 }
 
 files = append(files, file)
+
 return nil
 })
 if walkErr != nil {

archives_test.go

@@ -1,11 +1,13 @@
 package archives
 
 import (
+"context"
 "fmt"
 "os"
 "path/filepath"
 "reflect"
 "runtime"
+"sort"
 "strings"
 "testing"
 )
@@ -510,3 +512,46 @@ func TestFollowSymlink(t *testing.T) {
 }
 })
 }
+
+func TestFilesFromDisk_SymlinkOutsideFileNamesMap(t *testing.T) {
+tmpDir := t.TempDir()
+otherTmpDir := t.TempDir()
+
+testDirName := "test_dir"
+testDir := filepath.Join(otherTmpDir, testDirName)
+if err := os.Mkdir(testDir, 0755); err != nil {
+t.Fatal(err)
+}
+
+testFileName := "test.txt"
+testFile := filepath.Join(testDir, testFileName)
+if err := os.WriteFile(testFile, []byte("test content"), 0644); err != nil {
+t.Fatal(err)
+}
+
+symlinkDirName := "symlink_dir"
+symlinkDir := filepath.Join(tmpDir, symlinkDirName)
+if err := os.Symlink(testDir, symlinkDir); err != nil {
+t.Fatal(err)
+}
+
+files, err := FilesFromDisk(context.Background(), &FromDiskOptions{
+FollowSymlinks: true,
+}, map[string]string{symlinkDir: ""})
+if err != nil {
+t.Fatal(err)
+}
+
+sort.Slice(files, func(i, j int) bool {
+return files[i].NameInArchive < files[j].NameInArchive
+})
+
+if files[0].NameInArchive != symlinkDirName {
+t.Fatalf("expected file name '%s', got '%s'", symlinkDirName, files[0].NameInArchive)
+}
+
+testFilePath := filepath.Join(symlinkDirName, testFileName)
+if files[1].NameInArchive != testFilePath {
+t.Fatalf("expected file name '%s', got '%s'", testFilePath, files[1].NameInArchive)
+}
+}