QByteArray/QString: add resizeForOverwrite

For these classes it's not really a new feature, but exposing
the current resize() behavior (which does uninitialized resizes)
under a proper name.

Changing the existing behavior for resize() is a behavioral
break that we can only likely afford in Qt 7.

[ChangeLog][QtCore][QString] Added resizeForOverwrite().
[ChangeLog][QtCore][QByteArray] Added resizeForOverwrite().

Change-Id: I15b3104aee2bc29d23e91d97b0e64f87612d0099
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/text/qbytearray.cpp

@@ -1896,6 +1896,21 @@ void QByteArray::resize(qsizetype newSize, char c)
         memset(d.data() + old, c, d.size - old);
 }
 
+/*!
+    \since 6.8
+
+    Resizes the byte array to \a size bytes. If the size of the
+    byte array grows, the new bytes are uninitialized.
+
+    The behavior is identical to \c{resize(size)}.
+
+    \sa resize()
+*/
+void QByteArray::resizeForOverwrite(qsizetype size)
+{
+    resize(size);
+}
+
 /*!
     Sets every byte in the byte array to \a ch. If \a size is different from -1
     (the default), the byte array is resized to size \a size beforehand.

src/corelib/text/qbytearray.h

@@ -105,6 +105,7 @@ public:
     bool isEmpty() const noexcept { return size() == 0; }
     void resize(qsizetype size);
     void resize(qsizetype size, char c);
+    void resizeForOverwrite(qsizetype size);
 
     QByteArray &fill(char c, qsizetype size = -1);
 

src/corelib/text/qstring.cpp

@@ -2680,6 +2680,24 @@ void QString::resize(qsizetype newSize, QChar fillChar)
         std::fill_n(d.data() + oldSize, difference, fillChar.unicode());
 }
 
+
+/*!
+    \since 6.8
+
+    Sets the size of the string to \a size characters. If the size of
+    the string grows, the new characters are uninitialized.
+
+    The behavior is identical to \c{resize(size)}.
+
+    \sa resize()
+*/
+
+void QString::resizeForOverwrite(qsizetype size)
+{
+    resize(size);
+}
+
+
 /*! \fn qsizetype QString::capacity() const
 
     Returns the maximum number of characters that can be stored in

src/corelib/text/qstring.h

@@ -190,6 +190,7 @@ public:
     inline bool isEmpty() const noexcept { return d.size == 0; }
     void resize(qsizetype size);
     void resize(qsizetype size, QChar fillChar);
+    void resizeForOverwrite(qsizetype size);
 
     QString &fill(QChar c, qsizetype size = -1);
     void truncate(qsizetype pos);