V4: fix range splitting when split is between intervals.

Also added some "white-box" unit tests and sprinkled in a bit of
documentation. The case that went wrong is covered by the test
rangeSplitting_1: before the fix, the new interval would have
two ranges: [66-64],[70-71]. The first range is invalid and should not
be there at all.

Change-Id: If0742f4e6a96d98ea5d696f95126886ba66f92bb
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

3 files changed, 168 insertions, 1 deletions

diff --git a/tests/auto/qml/qml.pro b/tests/auto/qml/qml.pro
index eec6584472..a330cd43aa 100644
--- a/tests/auto/qml/qml.pro
+++ b/tests/auto/qml/qml.pro
@@ -58,7 +58,8 @@ PRIVATETESTS += \
     qqmltimer \
     qqmlinstantiator \
     qv4debugger \
-    qqmlenginecleanup
+    qqmlenginecleanup \
+    v4misc
 
 qtHaveModule(widgets) {
     PUBLICTESTS += \
diff --git a/tests/auto/qml/v4misc/tst_v4misc.cpp b/tests/auto/qml/v4misc/tst_v4misc.cpp
new file mode 100644
index 0000000000..da2b793b71
--- /dev/null
+++ b/tests/auto/qml/v4misc/tst_v4misc.cpp
@@ -0,0 +1,157 @@
+/****************************************************************************
+**
+** Copyright (C) 2013 Digia Plc and/or its subsidiary(-ies).
+** Contact: http://www.qt-project.org/legal
+**
+** This file is part of the test suite of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** 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 Digia.  For licensing terms and
+** conditions see http://qt.digia.com/licensing.  For further information
+** use the contact form at http://qt.digia.com/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 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Digia gives you certain additional
+** rights.  These rights are described in the Digia Qt LGPL Exception
+** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include <qtest.h>
+
+#include <private/qv4ssa_p.h>
+
+class tst_v4misc: public QObject
+{
+    Q_OBJECT
+
+private slots:
+    void initTestCase();
+
+    void rangeSplitting_1();
+    void rangeSplitting_2();
+    void rangeSplitting_3();
+};
+
+QT_BEGIN_NAMESPACE
+// Avoid QHash randomization so that the temp numbering is stable.
+extern Q_CORE_EXPORT QBasicAtomicInt qt_qhash_seed; // from qhash.cpp
+QT_END_NAMESPACE
+
+using namespace QT_PREPEND_NAMESPACE(QQmlJS::V4IR);
+
+void tst_v4misc::initTestCase()
+{
+    qt_qhash_seed.store(0);
+    QCOMPARE(qt_qhash_seed.load(), 0);
+}
+
+// split between two ranges
+void tst_v4misc::rangeSplitting_1()
+{
+    LifeTimeInterval interval;
+    interval.addRange(59, 59);
+    interval.addRange(61, 62);
+    interval.addRange(64, 64);
+    interval.addRange(69, 71);
+    interval.validate();
+    QCOMPARE(interval.end(), 71);
+
+    LifeTimeInterval newInterval = interval.split(66, 70);
+    interval.validate();
+    newInterval.validate();
+    QVERIFY(newInterval.isSplitFromInterval());
+
+    QCOMPARE(interval.ranges().size(), 3);
+    QCOMPARE(interval.ranges()[0].start, 59);
+    QCOMPARE(interval.ranges()[0].end, 59);
+    QCOMPARE(interval.ranges()[1].start, 61);
+    QCOMPARE(interval.ranges()[1].end, 62);
+    QCOMPARE(interval.ranges()[2].start, 64);
+    QCOMPARE(interval.ranges()[2].end, 64);
+    QCOMPARE(interval.end(), 70);
+
+    QCOMPARE(newInterval.ranges().size(), 1);
+    QCOMPARE(newInterval.ranges()[0].start, 70);
+    QCOMPARE(newInterval.ranges()[0].end, 71);
+    QCOMPARE(newInterval.end(), 71);
+}
+
+// split in the middle of a range
+void tst_v4misc::rangeSplitting_2()
+{
+    LifeTimeInterval interval;
+    interval.addRange(59, 59);
+    interval.addRange(61, 64);
+    interval.addRange(69, 71);
+    interval.validate();
+    QCOMPARE(interval.end(), 71);
+
+    LifeTimeInterval newInterval = interval.split(62, 64);
+    interval.validate();
+    newInterval.validate();
+    QVERIFY(newInterval.isSplitFromInterval());
+
+    QCOMPARE(interval.ranges().size(), 2);
+    QCOMPARE(interval.ranges()[0].start, 59);
+    QCOMPARE(interval.ranges()[0].end, 59);
+    QCOMPARE(interval.ranges()[1].start, 61);
+    QCOMPARE(interval.ranges()[1].end, 62);
+    QCOMPARE(interval.end(), 64);
+
+    QCOMPARE(newInterval.ranges().size(), 2);
+    QCOMPARE(newInterval.ranges()[0].start, 64);
+    QCOMPARE(newInterval.ranges()[0].end, 64);
+    QCOMPARE(newInterval.ranges()[1].start, 69);
+    QCOMPARE(newInterval.ranges()[1].end, 71);
+    QCOMPARE(newInterval.end(), 71);
+}
+
+// split in the middle of a range, and let it never go back to active again
+void tst_v4misc::rangeSplitting_3()
+{
+    LifeTimeInterval interval;
+    interval.addRange(59, 59);
+    interval.addRange(61, 64);
+    interval.addRange(69, 71);
+    interval.validate();
+    QCOMPARE(interval.end(), 71);
+
+    LifeTimeInterval newInterval = interval.split(64, LifeTimeInterval::Invalid);
+    interval.validate();
+    newInterval.validate();
+    QVERIFY(!newInterval.isValid());
+
+    QCOMPARE(interval.ranges().size(), 2);
+    QCOMPARE(interval.ranges()[0].start, 59);
+    QCOMPARE(interval.ranges()[0].end, 59);
+    QCOMPARE(interval.ranges()[1].start, 61);
+    QCOMPARE(interval.ranges()[1].end, 64);
+    QCOMPARE(interval.end(), 71);
+}
+
+QTEST_MAIN(tst_v4misc)
+
+#include "tst_v4misc.moc"
diff --git a/tests/auto/qml/v4misc/v4misc.pro b/tests/auto/qml/v4misc/v4misc.pro
new file mode 100644
index 0000000000..d68025f410
--- /dev/null
+++ b/tests/auto/qml/v4misc/v4misc.pro
@@ -0,0 +1,9 @@
+CONFIG += testcase
+TARGET = tst_v4misc
+macx:CONFIG -= app_bundle
+
+SOURCES += tst_v4misc.cpp
+
+CONFIG += parallel_test
+QT += core-private qml-private testlib
+DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0