[Maniphest] [Created] T1861: Check for m_iface in every Archive methods

[elvisangelaccio (Elvis Angelaccio)]

elvisangelaccio created this task.
elvisangelaccio moved this task to In progress on the Ark workboard.

TASK DESCRIPTION
  Since we have introduced the concept of "archive instance with error" (using a dedicated constructor without `ArchiveInterface *` argument), we cannot anymore assume that `m_iface` is always not null.
  
  We currently don't trigger this kind of crashes, but this should be fixed anyway.

TASK DETAIL
  https://phabricator.kde.org/T1861

WORKBOARD
  https://phabricator.kde.org/project/board/46/

EMAIL PREFERENCES
  https://phabricator.kde.org/settings/panel/emailpreferences/

To: elvisangelaccio
Cc: kde-utils-devel, elvisangelaccio, tctara