1 files changed, 52 insertions, 7 deletions

diff --git a/src/corelib/tools/qbytearray.cpp b/src/corelib/tools/qbytearray.cpp
index 6cc41a8956..9816b5cb32 100644
--- a/src/corelib/tools/qbytearray.cpp
+++ b/src/corelib/tools/qbytearray.cpp
@@ -165,7 +165,7 @@ int qFindByteArray(
     This function returns SIZE_MAX (~0) on overflow or if the memory block size
     would not fit an int.
 */
-size_t qCalculateBlockSize(size_t elementCount, size_t elementSize, size_t headerSize) Q_DECL_NOTHROW
+size_t qCalculateBlockSize(size_t elementCount, size_t elementSize, size_t headerSize) noexcept
 {
     unsigned count = unsigned(elementCount);
     unsigned size = unsigned(elementSize);
@@ -206,7 +206,7 @@ size_t qCalculateBlockSize(size_t elementCount, size_t elementSize, size_t heade
     needed.
 */
 CalculateGrowingBlockSizeResult
-qCalculateGrowingBlockSize(size_t elementCount, size_t elementSize, size_t headerSize) Q_DECL_NOTHROW
+qCalculateGrowingBlockSize(size_t elementCount, size_t elementSize, size_t headerSize) noexcept
 {
     CalculateGrowingBlockSizeResult result = {
         std::numeric_limits<size_t>::max(),std::numeric_limits<size_t>::max()
@@ -1281,7 +1281,7 @@ QByteArray qUncompress(const uchar* data, int nbytes)
     Assigns \a other to this byte array and returns a reference to
     this byte array.
 */
-QByteArray &QByteArray::operator=(const QByteArray & other) Q_DECL_NOTHROW
+QByteArray &QByteArray::operator=(const QByteArray & other) noexcept
 {
     other.d->ref.ref();
     if (!d->ref.deref())
@@ -1537,6 +1537,15 @@ QByteArray &QByteArray::operator=(const char *str)
     will apply to the character in the QByteArray from which you got
     the reference.
 
+    \note Before Qt 5.14 it was possible to use this operator to access
+    a character at an out-of-bounds position in the byte array, and
+    then assign to such position, causing the byte array to be
+    automatically resized. Furthermore, assigning a value to the
+    returned QByteRef would cause a detach of the byte array, even if the
+    byte array has been copied in the meanwhile (and the QByteRef kept
+    alive while the copy was taken). These behaviors are deprecated,
+    and will be changed in a future version of Qt.
+
     \sa at()
 */
 
@@ -3282,10 +3291,10 @@ static QByteArray toCase_template(T &input, const uchar * table)
     }
 
     if (firstBad == e)
-        return qMove(input);
+        return std::move(input);
 
     // transform the rest
-    QByteArray s = qMove(input);    // will copy if T is const QByteArray
+    QByteArray s = std::move(input);    // will copy if T is const QByteArray
     char *b = s.begin();            // will detach if necessary
     char *p = b + (firstBad - orig_begin);
     e = b + s.size();
@@ -4136,10 +4145,9 @@ ushort QByteArray::toUShort(bool *ok, int base) const
 
 double QByteArray::toDouble(bool *ok) const
 {
-    QByteArray nulled = nulTerminated();
     bool nonNullOk = false;
     int processed = 0;
-    double d = qt_asciiToDouble(nulled.constData(), nulled.length(),
+    double d = qt_asciiToDouble(constData(), size(),
                                 nonNullOk, processed, WhitespacesAllowed);
     if (ok)
         *ok = nonNullOk;
@@ -5055,4 +5063,41 @@ QByteArray QByteArray::toPercentEncoding(const QByteArray &exclude, const QByteA
     \sa QStringLiteral
 */
 
+namespace QtPrivate {
+namespace DeprecatedRefClassBehavior {
+void warn(WarningType w, EmittingClass c)
+{
+    static const char deprecatedBehaviorString[] =
+            "The corresponding behavior is deprecated, and will be changed"
+             " in a future version of Qt.";
+
+    const char *emittingClassName = nullptr;
+    const char *containerClassName = nullptr;
+
+    switch (c) {
+    case EmittingClass::QByteRef:
+        emittingClassName = "QByteRef";
+        containerClassName = "QByteArray";
+        break;
+    case EmittingClass::QCharRef:
+        emittingClassName = "QCharRef";
+        containerClassName = "QString";
+        break;
+    }
+
+    switch (w) {
+    case WarningType::OutOfRange:
+        qWarning("Using %s with an index pointing outside the valid range of a %s. %s",
+                 emittingClassName, containerClassName, deprecatedBehaviorString);
+        break;
+    case WarningType::DelayedDetach:
+        qWarning("Using %s with on a %s that is not already detached. %s",
+                 emittingClassName, containerClassName, deprecatedBehaviorString);
+        break;
+    }
+}
+} // namespace DeprecatedRefClassBehavior
+} // namespace QtPrivate
+
+
 QT_END_NAMESPACE