When awesome restarts because a new screen was added or removed, clients can end
up being on a different screen than before the restart. However, the tags will
be carried across the restart. This means that a client could end up being
tagged with a tag from another screen. This results in weird behavior of tag
switches and confuses users.
To work around this, remove the client from any tags that are on a different
screen during startup. If the client ends up without any tags, it will then be
tagged with the currently selected tags.
Signed-off-by: Uli Schlachter <psychon@znc.in>
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