icon missing from update-managers unity launcher

[amias]

using a fully upto date 13.10 install if i run :

sudo update_manager -d

observed: when the dist upgrade is happening the icon in the launcher is the big grey question mark default one.

expected: a non default icon although i can't think of what one might look like to reflect a dist-upgrade but at least
not the default 'no icon' one as it doesn't inspire confidence in the upgrade or product.

i know not a major issue but should be an easy fix and it stops the migrants winging .

the dist upgrade is working fine so far.

notes:
this is a recent 32bit install (3 weeks) from scratch that is being updated to 14.04 , no themes have been applied
and minimal customisations have occured , ostensibly this is as supplied.

the launcher size is 32

Cheers
Amias

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[joshas (joshas)]

This issue still exists in "Distribution Upgrade" on Ubuntu 17.10 when updating to 18.04.

[joshas (joshas)]

In the middle of installing upgrades correct icon appeared, but on side launcher it is blurry.