Add support for UTC[+-]\d+(:\d+){,2} time zone IDs

We presently only support the UTC-based offset timezones that are
listed in the CLDR; and it doesn't make sense to list more than these
in the list of available zones. However, if someone sets their TZ
environment variable to a conformant UTC-offset string, we should make
sense of it even if CLDR doesn't mention it. Only do so as final
fall-back, as backends may handle the givne name better (some such IDs
appear in the windows-compatibility list, for example).

Added tests for the new UTC-offset time-zone names.
Removed one test that relied on them not being supported.

[ChangeLog][QtCore][QTimeZone] The constructor can now handle general
UTC-offset zone names. The reported id() of such a zone shall be in
canonical form, so might not match the ID passed to the constructor.

Fixes: QTBUG-77738
Change-Id: I9a0aa68281a345c4717915c8a8fbc2978490d0aa
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/src/corelib/time/qtimezoneprivate_p.h b/src/corelib/time/qtimezoneprivate_p.h
index 5f6491ef81..a57f61f381 100644
--- a/src/corelib/time/qtimezoneprivate_p.h
+++ b/src/corelib/time/qtimezoneprivate_p.h
@@ -188,6 +188,9 @@ public:
     QUtcTimeZonePrivate(const QUtcTimeZonePrivate &other);
     virtual ~QUtcTimeZonePrivate();
 
+    // Fall-back for UTC[+-]\d+(:\d+){,2} IDs.
+    static qint64 offsetFromUtcString(const QByteArray &id);
+
     QUtcTimeZonePrivate *clone() const override;
 
     Data data(qint64 forMSecsSinceEpoch) const override;