Implement Python slicing support for QByteArray

PySide2 for Python 3 didn't support get item by slice, e.g.
```
>>> from PySide2.QtCore import QByteArray
>>> ba = QByteArray('1234567890')
>>> ba[2:4]
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: sequence index must be integer, not 'slice'
```
This is because get item by slice is supported by mp_subscript.
But current PySide2 doesn't implemented it. So I added __mgetitem__ in
QByteArray. And we also need to keep __getitem__ to support iterate over
QByteArray.
Also removed the __getslice__ from QByteArray.

Task-number: PYSIDE-567
Change-Id: I01f79cc2ab8700da92155cfad96be2e98bb8b331
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

1 files changed, 87 insertions, 0 deletions

diff --git a/sources/pyside2/PySide2/QtCore/glue/qbytearray_mgetitem.cpp b/sources/pyside2/PySide2/QtCore/glue/qbytearray_mgetitem.cpp
new file mode 100644
index 000000000..19b05e162
--- /dev/null
+++ b/sources/pyside2/PySide2/QtCore/glue/qbytearray_mgetitem.cpp
@@ -0,0 +1,87 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the Qt for Python project.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+if (PyIndex_Check(_key)) {
+    Py_ssize_t _i;
+    _i = PyNumber_AsSsize_t(_key, PyExc_IndexError);
+    if (_i < 0 || _i >= %CPPSELF.size()) {
+        PyErr_SetString(PyExc_IndexError, "index out of bounds");
+        return 0;
+    } else {
+        char res[2];
+        res[0] = %CPPSELF.at(_i);
+        res[1] = 0;
+        return PyBytes_FromStringAndSize(res, 1);
+    }
+} else if (PySlice_Check(_key)) {
+    Py_ssize_t start, stop, step, slicelength, cur;
+
+#ifdef IS_PY3K
+    PyObject *key = _key;
+#else
+    PySliceObject *key = reinterpret_cast<PySliceObject *>(_key);
+#endif
+    if (PySlice_GetIndicesEx(key, %CPPSELF.count(), &start, &stop, &step, &slicelength) < 0) {
+        return NULL;
+    }
+
+    QByteArray ba;
+    if (slicelength <= 0) {
+        return %CONVERTTOPYTHON[QByteArray](ba);
+    } else if (step == 1) {
+        Py_ssize_t max = %CPPSELF.count();
+        start = qBound(Py_ssize_t(0), start, max);
+        stop = qBound(Py_ssize_t(0), stop, max);
+        QByteArray ba;
+        if (start < stop)
+            ba = %CPPSELF.mid(start, stop - start);
+        return %CONVERTTOPYTHON[QByteArray](ba);
+    } else {
+        QByteArray ba;
+        for (cur = start; slicelength > 0; cur += static_cast<size_t>(step), slicelength--) {
+            ba.append(%CPPSELF.at(cur));
+        }
+        return %CONVERTTOPYTHON[QByteArray](ba);
+    }
+} else {
+    PyErr_Format(PyExc_TypeError,
+                 "list indices must be integers or slices, not %.200s",
+                 _key->ob_type->tp_name);
+    return NULL;
+}