I used the test desktop/test/deployment/website_update/web6.oxt together withe
the extension repository (extensions.services.openoffice...).

When the update dialog is open, then it shows an available udpate. Because web
based update was not supported before jl79, the update is only displayed when
the check box "Show all udpates" is checked. The description in missing that
this it is a browser based update, that is, it cannot be downloaded
automatically. When clicking on the disabled checkbox of the extension then it
crashes.

When jl79 is integrated, then "browser based updates" are immediately displayed
and the error description does not exist any more. Then one may not reproduce
the problem with this test case. However, this may also affect other scenarios,
for example when there is an update for a shared extension, which cannot be
installed because of insufficient user rights.