Further improve X500 addresses detection, don't overwrite existing address but do retain X500 address if available

[sanastasiadis]

To detect X500 addresses, the regular expression is used: "/o=[^/]+/ou=[^/]+(?:/cn=[^/]+)?"
This regular expression accepts only one appearance of "cn=".

It is possible to have X500 addresses with multiple "cn=" parts, eg: "/o=Test/ou=Unit/cn=Recipients/cn=anassta".
In this case the above regular expression will not work.

Proposed solution is to change the regular expression to search for "one or more" "cn=" parts, by changing the final "?" into "+".
Eg: "/o=[^/]+/ou=[^/]+(?:/cn=[^/]+)+".

I tested with the proposed regular expression and it works for both cases:

1. "/o=Test/ou=Unit/cn=Recipients/cn=anassta"
2. "/o=Test/ou=Unit/cn=anassta"

[bbottema]

Hi, thanks for helping out!

To detect X500 addresses, the regular expression is used: "/o=[^/]+/ou=[^/]+(?:/cn=[^/]+)?"
This regular expression accepts only one appearance of "cn=".

To be specific, it means it accepts at most only one. So it's optional.

Proposed solution is to change the regular expression to search for "one or more" "cn=" parts, by changing the final "?" into "+".
Eg: "/o=[^/]+/ou=[^/]+(?:/cn=[^/]+)+".

This, however, makes it mandatory (one or more).

I guess, the correct way to handle both the case you found and to be backwards compatible, is to make it zero or more. So

/o=[^/]+/ou=[^/]+(?:/cn=[^/]+)*

What do you think?

[sanastasiadis]

Yes, you are right. Using "*" was an afterthought for me as well.
I will align my PR.

[bbottema]

Change released in 1.13.1

[bbottema]

I may have to revert this change, as it caused a test case in Simple Java Mail to fail.

java.lang.AssertionError:
Expecting actual:
[Recipient{name='Sven Sielenkemper', address='sielenkemper@otris.de', type=To},
Recipient{name='sven.sielenkemper@gmail.com', address='sven.sielenkemper@gmail.com', type=To}]
to contain exactly (and in same order):
[Recipient{name='Sven Sielenkemper', address='/o=otris/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=ad5e65c5e53d40e2825d738a39904682-sielenkemper', type=To},
Recipient{name='sven.sielenkemper@gmail.com', address='sven.sielenkemper@gmail.com', type=To}]
but some elements were not found:
[Recipient{name='Sven Sielenkemper', address='/o=otris/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=ad5e65c5e53d40e2825d738a39904682-sielenkemper', type=To}]
and others were not expected:
[Recipient{name='Sven Sielenkemper', address='sielenkemper@otris.de', type=To}]

For the .eml and .msg files in this zip: #486 TestValidSigned messages.zip (from #40)

Perhaps you can have a look at it?