Bad query error when searching in GNOME Software (special chars snap)

[AsciiWolf]

If a user types "=" into the search bar in GNOME Software when searching for an application, he gets a "bad query" error instead of the actual search results.

Steps to reproduce:
1. Open GNOME Software.
2. Type "someapp=".

[Robert Ancell (robert-ancell)]

The bug appears to be in snapd which is returning this error.

[Robert Ancell (robert-ancell)]

From store/store.go in the snapd repository:

// these characters might have special meaning on the search
// server, and don't form part of a reasonable search, so
// abort if they're included.
//
// "-" might also be special on the server, but it's also a
// valid part of a package name, so we let it pass
if strings.ContainsAny(searchTerm, `+=&|><!(){}[]^"~*?:\/`) {
        return nil, ErrBadQuery
}

[Robert Ancell (robert-ancell)]

Testing shows +&><() seem to work fine, but =|!{}[]^"~*?:\/ do not.

[Robert Ancell (robert-ancell)]

I opened a forum topic to discuss with the snapd authors:
https://forum.snapcraft.io/t/special-characters-cause-searches-to-fail/2158

[AsciiWolf (asciiwolf)]

Still happening in Bionic.

[Michael Vogt (mvo)]

It seems what you need is the right error kind to distinguish this error, this is done in: https://github.com/snapcore/snapd/pull/4428 now