ipn: treat zero-length file state store file as missing
"errors"
"fmt"
"io/ioutil"
+ "log"
"os"
"path/filepath"
"sync"
@@ -100,6 +101,14 @@ func (s *FileStore) String() string { return fmt.Sprintf("FileStore(%q)", s.path
// NewFileStore returns a new file store that persists to path.
func NewFileStore(path string) (*FileStore, error) {
bs, err := ioutil.ReadFile(path)
+
+ // Treat an empty file as a missing file.
+ // (https://github.com/tailscale/tailscale/issues/895#issuecomment-723255589)
+ if err == nil && len(bs) == 0 {
+ log.Printf("ipn.NewFileStore(%q): file empty; treating it like a missing file [warning]", path)
+ err = os.ErrNotExist
+ }
+
if err != nil {
if os.IsNotExist(err) {
// Write out an initial file, to verify that we can write
