GPG remove notation piping in input failing due to control character

[shombando]

GPG doesn't provide unattended notation manipulation capabilities through the cli to my knowledge. While "interactively" sending the notation information works for GPG during adding a notation. GPG rejects deleting the notation since it has to be sent with a control character and GPG has no knowledge that I'm not trying to add this notation. I've not been able to escape the "-" to sneak it past.

The function called deleteNotation is intended to interact with GPG and edit a key to remove a notation. This function is setup exactly the same addNotation^refactor which works just fine. The relevant snippet is here where removeNotation just prepends a "-" to the notation string:

   removeNotation="-$1"
   {
      echo notation
      echo $removeNotation
      echo save
   } | gpg --command-fd=0 --status-fd=1 --edit-key $fingerPrint

The relevant commit is: 5489d68

Here's the output and error:

gpg (GnuPG) 2.2.19; Copyright (C) 2019 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

[GNUPG:] REMOVED THE KEY INFO THAT IS PRINTED

[GNUPG:] GET_LINE keyedit.prompt
[GNUPG:] GOT_IT
[GNUPG:] GET_LINE keyedit.add_notation
[GNUPG:] GOT_IT
gpg: a notation value must not use any control characters

[GNUPG:] GET_LINE keyedit.prompt
[GNUPG:] GOT_IT
Key not changed so no update needed.

I'm opening this issue to seek help from the community.

[refactor]: after this issue is resolved the idea is to refactor to a single modifyNotation function.