Fix the condition in QWidgetPrivate::resolveLocale() to decide whether
to propagate locale: make it match setLocale_helper()'s condition when
deciding whether to propagate to descendants. This lead to a
QDateTimeEdit's calendar popup not getting told what locale to use
correctly, unless we setLocale() on it overtly, which then blocked
propagation of locale changes to it unless QDateTimeEdit manually
propagated the changes.
Fix the documentation of WA_WindowPropagation to mention locale as
also being propagated (which it was in several places, only neglecting
this one in resolveLocale).
[ChangeLog][QWidget][Qt::WA_WindowPropagation] Propagate locale
consistently, along with font and palette, within the widget
hierarchy. Previously, locale was propagated on ancestral
setLocale(), but not on creation of the descendant.
Task-number: QTBUG-59106
Change-Id: I92270f7789c8eda66a458274a658c84c7b0df754
Reviewed-by: David Faure <david.faure@kdab.com>