Detect stale symlinks by scanning target

main.go

@@ -471,45 +471,48 @@ func moveDirContents(srcDir, destDir string) error {
 }
 
 func findStaleLinks(filesDir, targetRoot string) ([]string, error) {
-	known := make(map[string]struct{})
-
-	err := filepath.WalkDir(filesDir, func(path string, entry fs.DirEntry, err error) error {
-		if err != nil {
-			return err
-		}
-		if path == filesDir || entry.IsDir() {
-			return nil
-		}
-		rel, err := filepath.Rel(filesDir, path)
-		if err != nil {
-			return err
-		}
-		known[filepath.Join(targetRoot, rel)] = struct{}{}
-		return nil
-	})
+	filesAbs, err := filepath.Abs(filesDir)
 	if err != nil {
 		return nil, err
 	}
 
 	var stale []string
-	for targetPath := range known {
-		info, err := os.Lstat(targetPath)
-		if errors.Is(err, os.ErrNotExist) {
-			continue
-		}
+	walkErr := filepath.WalkDir(targetRoot, func(path string, entry fs.DirEntry, err error) error {
 		if err != nil {
-			return nil, err
+			return err
+		}
+		if entry.IsDir() {
+			return nil
+		}
+		info, err := entry.Info()
+		if err != nil {
+			return err
 		}
 		if info.Mode()&os.ModeSymlink == 0 {
-			continue
+			return nil
 		}
-		src, err := os.Readlink(targetPath)
+
+		src, err := os.Readlink(path)
 		if err != nil {
-			return nil, err
+			return err
 		}
+		if !filepath.IsAbs(src) {
+			src = filepath.Join(filepath.Dir(path), src)
+		}
+		src = filepath.Clean(src)
+
+		if !strings.HasPrefix(src, filesAbs+string(os.PathSeparator)) && src != filesAbs {
+			return nil
+		}
+
 		if _, err := os.Stat(src); errors.Is(err, os.ErrNotExist) {
-			stale = append(stale, targetPath)
+			stale = append(stale, path)
 		}
+		return nil
+	})
+
+	if walkErr != nil {
+		return nil, walkErr
 	}
 
 	return stale, nil