Ensure QLocale's shared C-locale QLocalePrivate is never deleted

Other static data such as QTextStream might be initialized before the
static C-locale, in which case QLocale would adopt c_private and bump
the ref-count to 2, only to see it reset back to 1 when the c_locale's
static initialization happened.

The result was that at application shutdown the ref-count would fall
down to 0, and we tried deleting the static data.

This issue was observed with clang in a debug build, where the c_private
is initialized at runtime.

Change-Id: If05221a5e87886e1805ad3c1b1520483f425c0fb
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

1 files changed, 7 insertions, 3 deletions

diff --git a/src/corelib/tools/qlocale.cpp b/src/corelib/tools/qlocale.cpp
index fb233c0640..0eb202c5e2 100644
--- a/src/corelib/tools/qlocale.cpp
+++ b/src/corelib/tools/qlocale.cpp
@@ -531,7 +531,11 @@ static const QLocaleData *default_data = 0;
 static uint default_number_options = 0;
 
 static const QLocaleData *const c_data = locale_data;
-static QLocalePrivate c_private = { c_data, Q_BASIC_ATOMIC_INITIALIZER(1), 0 };
+static QLocalePrivate *c_private()
+{
+    static QLocalePrivate c_locale = { c_data, Q_BASIC_ATOMIC_INITIALIZER(1), 0 };
+    return &c_locale;
+}
 
 #ifndef QT_NO_SYSTEMLOCALE
 
@@ -700,7 +704,7 @@ Q_GLOBAL_STATIC_WITH_ARGS(QSharedDataPointer<QLocalePrivate>, defaultLocalePriva
 static QLocalePrivate *localePrivateByName(const QString &name)
 {
     if (name == QLatin1String("C"))
-        return &c_private;
+        return c_private();
     return QLocalePrivate::create(findLocaleData(name));
 }
 
@@ -708,7 +712,7 @@ static QLocalePrivate *findLocalePrivate(QLocale::Language language, QLocale::Sc
                                          QLocale::Country country)
 {
     if (language == QLocale::C)
-        return &c_private;
+        return c_private();
 
     const QLocaleData *data = QLocaleData::findLocaleData(language, script, country);