Store returns snap metadata containing carriage return characters

[Robert Ancell]

While investigating bug 1702539 in GNOME Software I found that snapd was returning '\r\n' for line endings for some snap descriptions (the rest were just '\n'). Prompting the store shows these appear to be coming from there:

$ http --json https://api.snapcraft.io/api/v1/snaps/details/hiri X-Ubuntu-Series:16 fields==description
HTTP/1.1 200 OK
Content-Length: 397
Content-Type: application/json
Date: Thu, 14 Sep 2017 08:39:05 GMT
Server: gunicorn/19.7.1
X-Request-Id: 8396f777-47bb-4d25-941b-f868d1b04f2a
X-VCS-Revision: 5f3da77

{
    "description": "Hiri is an email client for Office 365 / Exchange / outlook.com / msn.com / hotmail.com / live.com. Basically all the Microsoft Email services :)\r\n\r\nHiri has full email, calendar and tasks functionality.\r\n\r\nHiri is a subscription service but you do have 14 days free to try it to see if you like it. \r\n\r\nVisit www.hiri.com for more information.",
    "package_name": "hiri"
}

When discussing on the forum [1] it was suggested that these might have come from the store HTML form input.

Regardless of the source, it would be ideal to standardise the newline character, and I propose to use '\n'. This might require the store to filter input to extract the carriage returns.

[1] https://forum.snapcraft.io/t/snap-metadata-newline-characters/2116