Description of problem:
I tried to download the public key for Ken Coar, and got a very confusing error
message. I then logged in as a different user, and tried again, and it
succeeded. The import filter is over-active, and appears to be refusing to
import a key solely because an 8-digit identifier associated with the key
happens to have a substring that matches the username associated with my own
personal key.

Version-Release number of selected component (if applicable):
gnupg-1.4.18-1.fc20.x86_64

How reproducible:
100% for me, but not for all users

Steps to Reproduce:

1. Create a personal gpg key associated with a short all-hex username. In my

case, although my $USER of eblake is non-hex, my key happens to be associated
with a secondary email address ebb9@byu.net: gpg --fingerprint eblake

2. Try to download another public subkey where the associated master key has the

same all-hex substring: gpg --recv-keys f46d6ac2

3. Try to inspect the key: gpg --fingerprint 0xf46d6ac2
4. As a work-around, import the subkey directly: gpg --fingerprint 0xf46d6ac2
5. Now try to inspect it: gpg --fingerprint 0xf46d6ac2
6. Log on as a different user: su -l dummy; echo $USER
7. Try again to download: gpg --recv-keys f46d6ac2

Actual results:

1. $ gpg --fingerprint eblake

pub 2048R/2527436A 2010-04-16

Key fingerprint = 71C2 CC22 B1C4 6029 27D2  F3AA A7A1 6B4A 2527 436A

uid Eric Blake <eblake@redhat.com>
uid Eric Blake (Free Software Programmer) <ebb9@byu.net>
uid [jpeg image of size 6874]
sub 2048R/D2E4726C 2010-04-16

2. $ gpg --recv-keys f46d6ac2

gpg: requesting key F46D6AC2 from hkp server keys.gnupg.net
gpg: key 4EBB96FF: rejected by import filter
gpg: Total number processed: 1

3. $ gpg --fingerprint 0xf46d6ac2

gpg: error reading key: public key not found

4. $ gpg --recv-keys 4ebb96ff

gpg: requesting key 4EBB96FF from hkp server keys.gnupg.net
gpg: key 4EBB96FF: public key "Ken Coar (Open sourcerer) <coar@apache.org>" imported
gpg: 3 marginal(s) needed, 1 complete(s) needed, classic trust model
gpg: depth: 0 valid: 1 signed: 6 trust: 0-, 0q, 0n, 0m, 0f, 1u
gpg: depth: 1 valid: 6 signed: 46 trust: 0-, 4q, 0n, 0m, 2f, 0u
gpg: depth: 2 valid: 41 signed: 29 trust: 1-, 1q, 0n, 28m, 11f, 0u
gpg: depth: 3 valid: 10 signed: 21 trust: 0-, 6q, 0n, 1m, 3f, 0u
gpg: depth: 4 valid: 4 signed: 9 trust: 2-, 1q, 0n, 0m, 1f, 0u
gpg: next trustdb check due at 2015-01-29
gpg: Total number processed: 1
gpg: imported: 1 (RSA: 1)

5. $ gpg --fingerprint 0xf46d6ac2

pub 4096R/4EBB96FF 1997-01-24

Key fingerprint = 4333 9E61 30A2 CA74 206F  8653 5ADF 9B5C 4EBB 96FF

uid Ken Coar (Open sourcerer) <coar@apache.org>
uid Ken Coar (Open sourcerer, PHP hacker) <coar@php.net>
uid Ken Coar (Open sourcerer, opinionist) <Ken@Coar.Org>
uid Ken Coar (Open sourcerer, Perl hacker) <ROUS@CPAN.Org>
uid Ken Coar (Open methodology evangelist) <coar@opensource.org>
uid Ken Coar (Opinionist [eddress retired]) <Ken.Coar@Golux.Com>
uid Ken Coar/Rodent of Unusual Size (Born 1960-04, Florida, USA)
uid Ken Coar (Opinionist [eddress retired]) <Ken.Coar@MeepZor.Com>
uid Ken Coar (Open sourcerer, systems rationaliser)
<coar@redhat.com>
uid Ken Coar (Open sourcerer, systems rationaliser)
<kcoar@redhat.com>
uid Ken Coar (Open sourcerer, systems rationaliser)
<genghisken@redhat.com>
uid Ken Coar (Open sourcerer, opinionist, fallback eddress)
<Ken.Coar@GMail.Com>
sub 2048R/5D5F76E9 1997-01-24
sub 1024D/31F752F3 2014-07-22 [expires: 2016-07-21]
sub 4096R/F46D6AC2 2014-07-22 [expires: 2016-07-21]

6. echo $USER

dummy

7. $ gpg --recv-keys f46d6ac2

gpg: requesting key F46D6AC2 from hkp server keys.gnupg.net
gpg: key 4EBB96FF: public key "Ken Coar (Open sourcerer) <coar@apache.org>" imported
gpg: no ultimately trusted keys found
gpg: Total number processed: 1
gpg: imported: 1 (RSA: 1)

Expected results:

At step 2, the input filter should not have prevented me from getting the key.
I should not have had to resort to either step 4 (change my download request) or
7 (log on as a different user)