1 files changed, 51 insertions, 35 deletions

diff --git a/src/corelib/tools/qlocale.cpp b/src/corelib/tools/qlocale.cpp
index a072ea411c..5598dfe237 100644
--- a/src/corelib/tools/qlocale.cpp
+++ b/src/corelib/tools/qlocale.cpp
@@ -64,6 +64,9 @@
 #include "qstringbuilder.h"
 #include "private/qnumeric_p.h"
 #include <cmath>
+#ifndef QT_NO_SYSTEMLOCALE
+#   include "qmutex.h"
+#endif
 #ifdef Q_OS_WIN
 #   include <qt_windows.h>
 #   include <time.h>
@@ -107,31 +110,32 @@ QLocale::Language QLocalePrivate::codeToLanguage(QStringView code) Q_DECL_NOTHRO
             return QLocale::Language((c - language_code_list)/3);
     }
 
-    // legacy codes
-    if (uc1 == 'n' && uc2 == 'o' && uc3 == 0) { // no -> nb
-        Q_STATIC_ASSERT(QLocale::Norwegian == QLocale::NorwegianBokmal);
-        return QLocale::Norwegian;
-    }
-    if (uc1 == 't' && uc2 == 'l' && uc3 == 0) { // tl -> fil
-        Q_STATIC_ASSERT(QLocale::Tagalog == QLocale::Filipino);
-        return QLocale::Tagalog;
-    }
-    if (uc1 == 's' && uc2 == 'h' && uc3 == 0) { // sh -> sr[_Latn]
-        Q_STATIC_ASSERT(QLocale::SerboCroatian == QLocale::Serbian);
-        return QLocale::SerboCroatian;
-    }
-    if (uc1 == 'm' && uc2 == 'o' && uc3 == 0) { // mo -> ro
-        Q_STATIC_ASSERT(QLocale::Moldavian == QLocale::Romanian);
-        return QLocale::Moldavian;
+    if (uc3 == 0) {
+        // legacy codes
+        if (uc1 == 'n' && uc2 == 'o') { // no -> nb
+            Q_STATIC_ASSERT(QLocale::Norwegian == QLocale::NorwegianBokmal);
+            return QLocale::Norwegian;
+        }
+        if (uc1 == 't' && uc2 == 'l') { // tl -> fil
+            Q_STATIC_ASSERT(QLocale::Tagalog == QLocale::Filipino);
+            return QLocale::Tagalog;
+        }
+        if (uc1 == 's' && uc2 == 'h') { // sh -> sr[_Latn]
+            Q_STATIC_ASSERT(QLocale::SerboCroatian == QLocale::Serbian);
+            return QLocale::SerboCroatian;
+        }
+        if (uc1 == 'm' && uc2 == 'o') { // mo -> ro
+            Q_STATIC_ASSERT(QLocale::Moldavian == QLocale::Romanian);
+            return QLocale::Moldavian;
+        }
+        // Android uses the following deprecated codes
+        if (uc1 == 'i' && uc2 == 'w') // iw -> he
+            return QLocale::Hebrew;
+        if (uc1 == 'i' && uc2 == 'n') // in -> id
+            return QLocale::Indonesian;
+        if (uc1 == 'j' && uc2 == 'i') // ji -> yi
+            return QLocale::Yiddish;
     }
-    // Android uses the following deprecated codes
-    if (uc1 == 'i' && uc2 == 'w' && uc3 == 0) // iw -> he
-        return QLocale::Hebrew;
-    if (uc1 == 'i' && uc2 == 'n' && uc3 == 0) // in -> id
-        return QLocale::Indonesian;
-    if (uc1 == 'j' && uc2 == 'i' && uc3 == 0) // ji -> yi
-        return QLocale::Yiddish;
-
     return QLocale::C;
 }
 
@@ -593,8 +597,6 @@ static QLocalePrivate *c_private()
 }
 
 #ifndef QT_NO_SYSTEMLOCALE
-
-
 /******************************************************************************
 ** Default system locale behavior
 */
@@ -683,14 +685,24 @@ void QLocalePrivate::updateSystemPrivate()
     if (!res.isNull())
         system_data->m_plus = res.toString().at(0).unicode();
 }
-#endif
+#endif // !QT_NO_SYSTEMLOCALE
 
 static const QLocaleData *systemData()
 {
 #ifndef QT_NO_SYSTEMLOCALE
-    // copy over the information from the fallback locale and modify
-    if (!system_data || system_data->m_language_id == 0)
-        QLocalePrivate::updateSystemPrivate();
+    /*
+      Copy over the information from the fallback locale and modify.
+
+      This modifies (cross-thread) global state, so take care to only call it in
+      one thread.
+    */
+    {
+        static QBasicMutex systemDataMutex;
+        systemDataMutex.lock();
+        if (!system_data || system_data->m_language_id == 0)
+            QLocalePrivate::updateSystemPrivate();
+        systemDataMutex.unlock();
+    }
 
     return system_data;
 #else
@@ -3151,11 +3163,15 @@ QString QLocaleData::longLongToString(const QChar zero, const QChar group,
         negative = false; // neither are negative numbers
     }
 
-    QString num_str;
-    if (base == 10)
-        num_str = qlltoa(l, base, zero);
-    else
-        num_str = qulltoa(l, base, zero);
+QT_WARNING_PUSH
+    /* "unary minus operator applied to unsigned type, result still unsigned" */
+QT_WARNING_DISABLE_MSVC(4146)
+    /*
+      Negating std::numeric_limits<qlonglong>::min() hits undefined behavior, so
+      taking an absolute value has to cast to unsigned to change sign.
+     */
+    QString num_str = qulltoa(negative ? -qulonglong(l) : qulonglong(l), base, zero);
+QT_WARNING_POP
 
     uint cnt_thousand_sep = 0;
     if (flags & ThousandsGroup && base == 10) {