Doc/QtBase: replace some 0 with \nullptr

Replace some 'is 0' or 'are 0' where 0 referes to a nullptr with 'is
\nullptr' and 'are \nullptr'

Change-Id: Ida9af2971924377efe2f49f435d79e109de2bdf4
Reviewed-by: André Hartmann <aha_1980@gmx.de>
Reviewed-by: Sze Howe Koh <szehowe.koh@gmail.com>

src/corelib/global/qglobal.cpp

@@ -702,7 +702,7 @@ Q_STATIC_ASSERT((std::is_same<qsizetype, qptrdiff>::value));
     64-bit integer literals in a platform-independent way. The
     Q_CHECK_PTR() macro prints a warning containing the source code's
     file name and line number, saying that the program ran out of
-    memory, if the pointer is 0. The qPrintable() and qUtf8Printable()
+    memory, if the pointer is \nullptr. The qPrintable() and qUtf8Printable()
     macros represent an easy way of printing text.
 
     The QT_POINTER_SIZE macro expands to the size of a pointer in bytes.
@@ -3263,7 +3263,7 @@ QByteArray QSysInfo::bootUniqueId()
     \macro void Q_CHECK_PTR(void *pointer)
     \relates <QtGlobal>
 
-    If \a pointer is 0, prints a message containing the source
+    If \a pointer is \nullptr, prints a message containing the source
     code's file name and line number, saying that the program ran out
     of memory and aborts program execution. It throws \c std::bad_alloc instead
     if exceptions are enabled.

src/corelib/io/qbuffer.cpp

@@ -227,7 +227,7 @@ QBuffer::~QBuffer()
 
     \snippet buffer/buffer.cpp 4
 
-    If \a byteArray is 0, the buffer creates its own internal
+    If \a byteArray is \nullptr, the buffer creates its own internal
     QByteArray to work on. This byte array is initially empty.
 
     \sa buffer(), setData(), open()

src/corelib/io/qiodevice.cpp

@@ -1829,7 +1829,7 @@ QByteArray QIODevicePrivate::peek(qint64 maxSize)
 /*! \fn bool QIODevice::getChar(char *c)
 
     Reads one character from the device and stores it in \a c. If \a c
-    is 0, the character is discarded. Returns \c true on success;
+    is \nullptr, the character is discarded. Returns \c true on success;
     otherwise returns \c false.
 
     \sa read(), putChar(), ungetChar()

src/corelib/kernel/qmetatype.cpp

@@ -457,7 +457,7 @@ struct DefinedTypesFilter {
     \deprecated
 
     Constructs a value of the given type which is a copy of \a copy.
-    The default value for \a copy is 0.
+    The default value for \a copy is \nullptr.
 
     Deprecated, use the static function QMetaType::create(int type,
     const void *copy) instead.

src/corelib/serialization/qtextstream.cpp

@@ -1681,7 +1681,7 @@ QString QTextStream::readLine(qint64 maxlen)
     \since 5.5
 
     Reads one line of text from the stream into \a line.
-    If \a line is 0, the read line is not stored.
+    If \a line is \nullptr, the read line is not stored.
 
     The maximum allowed line length is set to \a maxlen. If
     the stream contains lines longer than this, then the lines will be

src/network/access/qftp.cpp

@@ -1820,7 +1820,7 @@ int QFtp::cd(const QString &dir)
     \internal
     Downloads the file \a file from the server.
 
-    If \a dev is 0, then the readyRead() signal is emitted when there
+    If \a dev is \nullptr, then the readyRead() signal is emitted when there
     is data available to read. You can then read the data with the
     read() or readAll() functions.
 

src/network/socket/qudpsocket.cpp

@@ -479,7 +479,7 @@ QNetworkDatagram QUdpSocket::receiveDatagram(qint64 maxSize)
 /*!
     Receives a datagram no larger than \a maxSize bytes and stores
     it in \a data. The sender's host address and port is stored in
-    *\a address and *\a port (unless the pointers are 0).
+    *\a address and *\a port (unless the pointers are \nullptr).
 
     Returns the size of the datagram on success; otherwise returns
     -1.

src/opengl/qglframebufferobject.cpp

@@ -1395,7 +1395,7 @@ bool QGLFramebufferObject::hasOpenGLFramebufferBlit()
     Blits from the \a sourceRect rectangle in the \a source framebuffer
     object to the \a targetRect rectangle in the \a target framebuffer object.
 
-    If \a source or \a target is 0, the default framebuffer will be used
+    If \a source or \a target is \nullptr, the default framebuffer will be used
     instead of a framebuffer object as source or target respectively.
 
     The \a buffers parameter should be a mask consisting of any combination of