message: tests: check readability of cookie file
diff: @@ -326,7 +326,7 @@ def get_auth_cookie(datadir):
  if line.startswith("rpcpassword="):
  assert password is None # Ensure that there is only one rpcpassword line
  password = line.split("=")[1].strip("\n")
  - if os.path.isfile(os.path.join(datadir, "regtest", ".cookie")):
  + if os.path.isfile(os.path.join(datadir, "regtest", ".cookie")) and os.access(os.path.join(datadir, "regtest", ".cookie"), os.R_OK):
  with open(os.path.join(datadir, "regtest", ".cookie"), 'r', encoding="ascii") as f:
  userpass = f.read()
  split_userpass = userpass.split(':')
  