While common script typically adapts the surrounding script, it is
possible for strings of only punctuation (for instance) to remain
undetermined. In addition, Qt considers Latin and Common the same in
font matching, so in order to get merging for latin, we need to
conflate them in the application fallback API as well.
This also adds a couple of missing clears of caches (clearing
the font cache itself when adding a new fallback, since the
fallbacks are kept as part of the cached font engine + clearing
the fallback cache when adding a new application font, since the
new application font may be a fallback candidate).
Note: This also adds some missing removeApplicationFont() calls
from other tests, since these were causing issues with the
new test.
Task-number: QTBUG-124914
Change-Id: Idbfa0f6b492a9194eca67b57101e674f7b8a4ec4
Reviewed-by: Eirik Aavitsland <eirik.aavitsland@qt.io>
99e94f1035