action put validation error when code is the string "true"

[rabbah]

echo 'true' > oops.js

> wsk action create oops oop.js --kind nodejs:default
error: Unable to create action 'oops': There was an internal server error. (code pkXxz1XCQ1ACuw5bVLJRAcxfiCgS3gch)

controller logs show:

[2020-04-16T07:14:22.949Z] [ERROR] [#tid_9nDLFGWhC3gCXtau8wa7wgvNSZ94O9VS] [ActionsApi] [PUT] entity failed: Illegal base64 character a

wsk is posting the following PUT:

{"namespace":"_","name":"y","exec":{"kind":"nodejs:default","code":"true\n"}}

i suspect the b64 regex matches incorrectly and thinks true is base64 encoded string.

[rabbah]

The regex is

^([A-Za-z0-9+\/]{4})*([A-Za-z0-9+\/]{4}|[A-Za-z0-9+\/]{3}=|[A-Za-z0-9+\/]{2}==)$

which will match any 4 character string.

In the grand scheme, this is an unlikely bug (no valid function for the languages we support can match the base64 regex, I think) but fixing it is not a trivial amount of work because of the inter dependencies between API and tools.