Merge pull request #497 from fooishbar/download-validate-empty

download: Actually validate empty pathnames

actions/download_action.go

@@ -76,7 +76,7 @@ func (d *DownloadAction) validateFilename(context *debos.DebosContext, url *url.
  } else {
  filename = path.Base(d.Filename)
  }
- if len(filename) == 0 {
+ if len(filename) == 0 || filename == "." || filename == "/" {
  return "", fmt.Errorf("Incorrect filename is provided for '%s'", d.Url)
  }
  filename = path.Join(context.Scratchdir, filename)