bug#9255: Obscure epa-file error message

[Stefan Monnier <monnier@iro.umontreal.ca>]

>> Opening output file: Encrypt failed: ((exit) (invalid-recipient (reason
>> . 0) (requested-recipient . "36DB083C608CC24C")))
>> 
>> It turns out the problem was simply that my encryption key was expired.
>> Could someone figure out how to get a more helpful error message?

> I guess you won't get any further information even if you call gpg from
> the command line:

> $ gpg --encrypt -r A6CC6651 test.txt
> gpg: A6CC6651: skipped: unusable public key
> gpg: test.txt: encryption failed: unusable public key

It's not great, but "unusable public key" is a good improvement over
"Opening output file: Encrypt failed: ((exit) (invalid-recipient (reason
. 0) (requested-recipient . "36DB083C608CC24C")))"

I guess "invalid-recipient" does mean the same as "unusable public key"
at some level, but to this end user "unusable public key" is a lot
more clear.


        Stefan