5 files changed, 49 insertions, 0 deletions
diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index 4d83f19db7..82b2c10a93 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -591,6 +591,20 @@ bool QtPrivate::isLatin1(QStringView s) noexcept
     return true;
 }
 
+bool QtPrivate::isValidUtf16(QStringView s) noexcept
+{
+    Q_CONSTEXPR uint InvalidCodePoint = UINT_MAX;
+
+    QStringIterator i(s);
+    while (i.hasNext()) {
+        uint c = i.next(InvalidCodePoint);
+        if (c == InvalidCodePoint)
+            return false;
+    }
+
+    return true;
+}
+
 // conversion between Latin 1 and UTF-16
 void qt_from_latin1(ushort *dst, const char *str, size_t size) noexcept
 {
@@ -9046,6 +9060,21 @@ bool QString::isRightToLeft() const
     return QtPrivate::isRightToLeft(QStringView(*this));
 }
 
+/*!
+    \fn bool QString::isValidUtf16() const noexcept
+    \since 5.15
+
+    Returns \c true if the string contains valid UTF-16 encoded data,
+    or \c false otherwise.
+
+    Note that this function does not perform any special validation of the
+    data; it merely checks if it can be successfully decoded from UTF-16.
+    The data is assumed to be in host byte order; the presence of a BOM
+    is meaningless.
+
+    \sa QStringView::isValidUtf16()
+*/
+
 /*! \fn QChar *QString::data()
 
     Returns a pointer to the data stored in the QString. The pointer
diff --git a/src/corelib/text/qstring.h b/src/corelib/text/qstring.h
index 1669d7c94a..1f4e856660 100644
--- a/src/corelib/text/qstring.h
+++ b/src/corelib/text/qstring.h
@@ -919,6 +919,8 @@ public:
 
     bool isSimpleText() const;
     bool isRightToLeft() const;
+    Q_REQUIRED_RESULT bool isValidUtf16() const noexcept
+    { return QStringView(*this).isValidUtf16(); }
 
     QString(int size, Qt::Initialization);
     Q_DECL_CONSTEXPR inline QString(QStringDataPtr dd) : d(dd.ptr) {}
diff --git a/src/corelib/text/qstringalgorithms.h b/src/corelib/text/qstringalgorithms.h
index d54e376aa9..0b7774b4f3 100644
--- a/src/corelib/text/qstringalgorithms.h
+++ b/src/corelib/text/qstringalgorithms.h
@@ -99,6 +99,7 @@ Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool isAscii(QLatin1String
 Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool isAscii(QStringView   s) noexcept;
 Q_REQUIRED_RESULT Q_DECL_CONSTEXPR inline            bool isLatin1(QLatin1String s) noexcept;
 Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool isLatin1(QStringView   s) noexcept;
+Q_REQUIRED_RESULT Q_CORE_EXPORT Q_DECL_PURE_FUNCTION bool isValidUtf16(QStringView s) noexcept;
 
 } // namespace QtPRivate
 
diff --git a/src/corelib/text/qstringview.cpp b/src/corelib/text/qstringview.cpp
index 75de827583..c4ddb06ea4 100644
--- a/src/corelib/text/qstringview.cpp
+++ b/src/corelib/text/qstringview.cpp
@@ -865,6 +865,21 @@ QT_BEGIN_NAMESPACE
 */
 
 /*!
+    \fn bool QStringView::isValidUtf16() const
+    \since 5.15
+
+    Returns \c true if the string contains valid UTF-16 encoded data,
+    or \c false otherwise.
+
+    Note that this function does not perform any special validation of the
+    data; it merely checks if it can be successfully decoded from UTF-16.
+    The data is assumed to be in host byte order; the presence of a BOM
+    is meaningless.
+
+    \sa QString::isValidUtf16()
+*/
+
+/*!
     \fn QStringView::toWCharArray(wchar_t *array) const
     \since 5.14
 
diff --git a/src/corelib/text/qstringview.h b/src/corelib/text/qstringview.h
index 4ab4d2570f..06391ffef4 100644
--- a/src/corelib/text/qstringview.h
+++ b/src/corelib/text/qstringview.h
@@ -294,6 +294,8 @@ public:
 
     Q_REQUIRED_RESULT bool isRightToLeft() const noexcept
     { return QtPrivate::isRightToLeft(*this); }
+    Q_REQUIRED_RESULT bool isValidUtf16() const noexcept
+    { return QtPrivate::isValidUtf16(*this); }
 
     Q_REQUIRED_RESULT inline int toWCharArray(wchar_t *array) const; // defined in qstring.h