TypeError: Cannot read property 'length' of null

[clochix]

User is bulk deleting around 500 contacts just after importing them. Cf #301:

info - Contact controller | Starting bulk delete of 504 contacts
info - Contact controller | Starting bulk delete of 504 contacts
info - Contact controller | Deletion of 504 contacts done.
[Fri, 30 Sep 2016 10:14:33 GMT] - POST /contacts/bulk-delete - 200 - 8656.794 ms -  32
info - Contact controller | Deletion of 504 contacts done.
[Fri, 30 Sep 2016 10:14:33 GMT] - POST /contacts/bulk-delete - 200 - 2315.861 ms -  32
[Fri, 30 Sep 2016 10:14:36 GMT] - GET / - 200 - 282.246 ms -  -
[Fri, 30 Sep 2016 10:14:37 GMT] - GET /contacts - 200 - 40.613 ms -  906
[Fri, 30 Sep 2016 10:14:37 GMT] - GET /tags - 200 - 128.470 ms -  -
error - contact:application | {"type":"error","href":"https://92.cozycloud.cc/apps/contacts/#contacts","url":"https://92.cozycloud.cc/apps/contacts/scripts/app.js","line":"4","col":"20451"}
error - contact:application | Uncaught TypeError: Cannot read property 'length' of null
error - contact:application | TypeError: Cannot read property 'length' of null
    at o.exports.o.toggleResults (https://92.cozycloud.cc/apps/contacts/scripts/app.js:4:20451)
    at v (https://92.cozycloud.cc/apps/contacts/scripts/vendor.js:4:24520)
    at y (https://92.cozycloud.cc/apps/contacts/scripts/vendor.js:4:24254)
    at f (https://92.cozycloud.cc/apps/contacts/scripts/vendor.js:4:22173)
    at l.trigger (https://92.cozycloud.cc/apps/contacts/scripts/vendor.js:4:24147)
    at o.search (https://92.cozycloud.cc/apps/contacts/scripts/app.js:1:2698)
    at o.keyup @ui.search._.debounce.trailing (https://92.cozycloud.cc/apps/contacts/scripts/app.js:7:7249)
    at i (https://92.cozycloud.cc/apps/contacts/scripts/vendor.js:1:27782)
    at s (https://92.cozycloud.cc/apps/contacts/scripts/vendor.js:1:27878)
[Fri, 30 Sep 2016 10:14:37 GMT] - POST /log - 204 - 0.331 ms -  -