Port QLocalePrivate::*ToCode() to QLatin1String

The returned data is in US-ASCII (or else Latin-1), and resides in
consecutive memory. We can therefore return it in a QLatin1String,
which, however, will in general not be NUL-terminated.

Many users use the return value as part of a QStringBuilder
expression, and those which are not are not pessimized further by
this change.

The caller in qtimezoneprivate_icu looks as if it could simply zero
-terminate the return value and use it as-is, as opposed to
converting to UTF-8, but I left the code equivalent to the original
just the same.

Change-Id: I0e628af8c1320fcff8d0aacf160e859681d2b85a
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/src/corelib/tools/qtimezoneprivate_icu.cpp b/src/corelib/tools/qtimezoneprivate_icu.cpp
index 887486f567..a07b2593b9 100644
--- a/src/corelib/tools/qtimezoneprivate_icu.cpp
+++ b/src/corelib/tools/qtimezoneprivate_icu.cpp
@@ -477,9 +477,10 @@ QList<QByteArray> QIcuTimeZonePrivate::availableTimeZoneIds() const
 
 QList<QByteArray> QIcuTimeZonePrivate::availableTimeZoneIds(QLocale::Country country) const
 {
-    QByteArray regionCode = QLocalePrivate::countryToCode(country).toUtf8();
+    const QLatin1String regionCode = QLocalePrivate::countryToCode(country);
+    const QByteArray regionCodeUtf8 = QString(regionCode).toUtf8();
     UErrorCode status = U_ZERO_ERROR;
-    UEnumeration *uenum = ucal_openCountryTimeZones(regionCode, &status);
+    UEnumeration *uenum = ucal_openCountryTimeZones(regionCodeUtf8.data(), &status);
     QList<QByteArray> result;
     if (U_SUCCESS(status))
         result = uenumToIdList(uenum);