3 files changed, 9 insertions, 11 deletions
diff --git a/src/corelib/tools/qlocale.cpp b/src/corelib/tools/qlocale.cpp
index 9a46018ede..ebda40bd8d 100644
--- a/src/corelib/tools/qlocale.cpp
+++ b/src/corelib/tools/qlocale.cpp
@@ -3149,11 +3149,15 @@ 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) {
diff --git a/src/corelib/tools/qlocale_tools.cpp b/src/corelib/tools/qlocale_tools.cpp
index 3e4f37501e..4d969a4723 100644
--- a/src/corelib/tools/qlocale_tools.cpp
+++ b/src/corelib/tools/qlocale_tools.cpp
@@ -456,11 +456,6 @@ QString qulltoa(qulonglong l, int base, const QChar _zero)
     return QString(reinterpret_cast<QChar *>(p), 65 - (p - buff));
 }
 
-QString qlltoa(qlonglong l, int base, const QChar zero)
-{
-    return qulltoa(l < 0 ? -l : l, base, zero);
-}
-
 QString &decimalForm(QChar zero, QChar decimal, QChar group,
                      QString &digits, int decpt, int precision,
                      PrecisionMode pm,
diff --git a/src/corelib/tools/qlocale_tools_p.h b/src/corelib/tools/qlocale_tools_p.h
index 6133f67add..742abb4957 100644
--- a/src/corelib/tools/qlocale_tools_p.h
+++ b/src/corelib/tools/qlocale_tools_p.h
@@ -83,7 +83,6 @@ void doubleToAscii(double d, QLocaleData::DoubleForm form, int precision, char *
                    bool &sign, int &length, int &decpt);
 
 QString qulltoa(qulonglong l, int base, const QChar _zero);
-QString qlltoa(qlonglong l, int base, const QChar zero);
 Q_CORE_EXPORT QString qdtoa(qreal d, int *decpt, int *sign);
 
 enum PrecisionMode {