Merge remote-tracking branch 'origin/5.7' into dev

Conflicts:
	configure
	configure.json

Change-Id: Iba032d9a29c273da2585632bc6e22bbafb961808

10 files changed, 34 insertions, 20 deletions

diff --git a/src/widgets/itemviews/qabstractitemview.cpp b/src/widgets/itemviews/qabstractitemview.cpp
index 42e0cc7585..4768c58d1d 100644
--- a/src/widgets/itemviews/qabstractitemview.cpp
+++ b/src/widgets/itemviews/qabstractitemview.cpp
@@ -2604,12 +2604,11 @@ QModelIndexList QAbstractItemView::selectedIndexes() const
     QModelIndexList indexes;
     if (d->selectionModel) {
         indexes = d->selectionModel->selectedIndexes();
-        QList<QModelIndex>::iterator it = indexes.begin();
-        while (it != indexes.end())
-            if (isIndexHidden(*it))
-                it = indexes.erase(it);
-            else
-                ++it;
+        auto isHidden = [this](const QModelIndex &idx) {
+            return isIndexHidden(idx);
+        };
+        const auto end = indexes.end();
+        indexes.erase(std::remove_if(indexes.begin(), end, isHidden), end);
     }
     return indexes;
 }
diff --git a/src/widgets/itemviews/qabstractitemview_p.h b/src/widgets/itemviews/qabstractitemview_p.h
index a3af79abcb..60ae1559b1 100644
--- a/src/widgets/itemviews/qabstractitemview_p.h
+++ b/src/widgets/itemviews/qabstractitemview_p.h
@@ -277,7 +277,8 @@ public:
 
     const QEditorInfo &editorForIndex(const QModelIndex &index) const;
     inline bool hasEditor(const QModelIndex &index) const {
-        return indexEditorHash.find(index) != indexEditorHash.constEnd();
+        // Search's implicit cast (QModelIndex to QPersistentModelIndex) is slow; use cheap pre-test to avoid when we can.
+        return !indexEditorHash.isEmpty() && indexEditorHash.contains(index);
     }
 
     QModelIndex indexForEditor(QWidget *editor) const;
diff --git a/src/widgets/kernel/qwidget.cpp b/src/widgets/kernel/qwidget.cpp
index 6fa74b7cc6..a71089793c 100644
--- a/src/widgets/kernel/qwidget.cpp
+++ b/src/widgets/kernel/qwidget.cpp
@@ -281,6 +281,7 @@ QWidgetPrivate::QWidgetPrivate(int version)
 #endif
 #ifndef QT_NO_OPENGL
       , renderToTextureReallyDirty(1)
+      , renderToTextureComposeActive(0)
 #endif
 #if defined(Q_OS_WIN)
       , noPaintOnScreen(0)
diff --git a/src/widgets/kernel/qwidget_p.h b/src/widgets/kernel/qwidget_p.h
index 838236536a..71691a4afa 100644
--- a/src/widgets/kernel/qwidget_p.h
+++ b/src/widgets/kernel/qwidget_p.h
@@ -750,6 +750,7 @@ public:
 #endif
 #ifndef QT_NO_OPENGL
     uint renderToTextureReallyDirty : 1;
+    uint renderToTextureComposeActive : 1;
 #endif
 
     // *************************** Platform specific ************************************
diff --git a/src/widgets/kernel/qwidgetbackingstore.cpp b/src/widgets/kernel/qwidgetbackingstore.cpp
index ecaba584f2..32aabcec9f 100644
--- a/src/widgets/kernel/qwidgetbackingstore.cpp
+++ b/src/widgets/kernel/qwidgetbackingstore.cpp
@@ -67,6 +67,8 @@ QT_BEGIN_NAMESPACE
 
 extern QRegion qt_dirtyRegion(QWidget *);
 
+Q_GLOBAL_STATIC(QPlatformTextureList, qt_dummy_platformTextureList)
+
 /**
  * Flushes the contents of the \a backingStore into the screen area of \a widget.
  * \a tlwOffset is the position of the top level widget relative to the window surface.
@@ -109,6 +111,20 @@ void QWidgetBackingStore::qt_flush(QWidget *widget, const QRegion &region, QBack
         offset += widget->mapTo(tlw, QPoint());
 
 #ifndef QT_NO_OPENGL
+    const bool compositionWasActive = widget->d_func()->renderToTextureComposeActive;
+    if (!widgetTextures) {
+        widget->d_func()->renderToTextureComposeActive = false;
+        // Detect the case of falling back to the normal flush path when no
+        // render-to-texture widgets are visible anymore. We will force one
+        // last flush to go through the OpenGL-based composition to prevent
+        // artifacts. The next flush after this one will use the normal path.
+        if (compositionWasActive)
+            widgetTextures = qt_dummy_platformTextureList;
+    } else {
+        widget->d_func()->renderToTextureComposeActive = true;
+    }
+
+    // re-test since we may have been forced to this path via the dummy texture list above
     if (widgetTextures) {
         qt_window_private(tlw->windowHandle())->compositing = true;
         widget->window()->d_func()->sendComposeStatus(widget->window(), false);
@@ -970,8 +986,6 @@ static void findAllTextureWidgetsRecursively(QWidget *tlw, QWidget *widget)
     }
 }
 
-Q_GLOBAL_STATIC(QPlatformTextureList, qt_dummy_platformTextureList)
-
 static QPlatformTextureList *widgetTexturesFor(QWidget *tlw, QWidget *widget)
 {
     foreach (QPlatformTextureList *tl, QWidgetPrivate::get(tlw)->topData()->widgetTextures) {
diff --git a/src/widgets/widgets/qabstractspinbox.cpp b/src/widgets/widgets/qabstractspinbox.cpp
index b33984e6c6..774f5a708d 100644
--- a/src/widgets/widgets/qabstractspinbox.cpp
+++ b/src/widgets/widgets/qabstractspinbox.cpp
@@ -1418,7 +1418,7 @@ QStyle::SubControl QAbstractSpinBoxPrivate::newHoverControl(const QPoint &pos)
 
 QString QAbstractSpinBoxPrivate::stripped(const QString &t, int *pos) const
 {
-    QString text = t;
+    QStringRef text(&t);
     if (specialValueText.size() == 0 || text != specialValueText) {
         int from = 0;
         int size = text.size();
@@ -1440,7 +1440,7 @@ QString QAbstractSpinBoxPrivate::stripped(const QString &t, int *pos) const
     text = text.trimmed();
     if (pos)
         (*pos) -= (s - text.size());
-    return text;
+    return text.toString();
 
 }
 
diff --git a/src/widgets/widgets/qdockarealayout.cpp b/src/widgets/widgets/qdockarealayout.cpp
index 3b185a5e67..55e774024a 100644
--- a/src/widgets/widgets/qdockarealayout.cpp
+++ b/src/widgets/widgets/qdockarealayout.cpp
@@ -2168,6 +2168,9 @@ bool QDockAreaLayoutInfo::updateTabBar() const
     if (oldCurrentId > 0 && currentTabId() != oldCurrentId)
         that->setCurrentTabId(oldCurrentId);
 
+    if (QDockWidgetGroupWindow *dwgw = qobject_cast<QDockWidgetGroupWindow *>(tabBar->parent()))
+        dwgw->adjustFlags();
+
     //returns if the tabbar is visible or not
     return ( (gap ? 1 : 0) + tabBar->count()) > 1;
 }
diff --git a/src/widgets/widgets/qdockwidget.cpp b/src/widgets/widgets/qdockwidget.cpp
index e8c5502ae6..d2fa9a7c06 100644
--- a/src/widgets/widgets/qdockwidget.cpp
+++ b/src/widgets/widgets/qdockwidget.cpp
@@ -1390,8 +1390,6 @@ void QDockWidget::changeEvent(QEvent *event)
                 if (QDockAreaLayoutInfo *info = winLayout->layoutState.dockAreaLayout.info(this))
                     info->updateTabBar();
             }
-            if (QDockWidgetGroupWindow *p = qobject_cast<QDockWidgetGroupWindow *>(parent()))
-                p->adjustFlags();
         }
 #endif // QT_NO_TABBAR
         break;
@@ -1481,9 +1479,6 @@ bool QDockWidget::event(QEvent *event)
         }
         if (!isFloating() && layout != 0 && onTop)
             layout->raise(this);
-        if (QDockWidgetGroupWindow *p = qobject_cast<QDockWidgetGroupWindow *>(parent()))
-            p->adjustFlags();
-
         break;
     }
     case QEvent::WindowActivate:
diff --git a/src/widgets/widgets/qtabbar.cpp b/src/widgets/widgets/qtabbar.cpp
index 8c808f98cb..fe04299b92 100644
--- a/src/widgets/widgets/qtabbar.cpp
+++ b/src/widgets/widgets/qtabbar.cpp
@@ -1413,13 +1413,13 @@ static QString computeElidedText(Qt::TextElideMode mode, const QString &text)
     QString ret;
     switch (mode) {
     case Qt::ElideRight:
-        ret = text.left(2) + Ellipses;
+        ret = text.leftRef(2) + Ellipses;
         break;
     case Qt::ElideMiddle:
-        ret = text.left(1) + Ellipses + text.right(1);
+        ret = text.leftRef(1) + Ellipses + text.rightRef(1);
         break;
     case Qt::ElideLeft:
-        ret = Ellipses + text.right(2);
+        ret = Ellipses + text.rightRef(2);
         break;
     case Qt::ElideNone:
         ret = text;
diff --git a/src/widgets/widgets/qtextbrowser.cpp b/src/widgets/widgets/qtextbrowser.cpp
index 45da34c383..df92fc0e1e 100644
--- a/src/widgets/widgets/qtextbrowser.cpp
+++ b/src/widgets/widgets/qtextbrowser.cpp
@@ -302,7 +302,7 @@ void QTextBrowserPrivate::setSource(const QUrl &url)
             qWarning("QTextBrowser: No document for %s", url.toString().toLatin1().constData());
 
         if (q->isVisible()) {
-            QString firstTag = txt.left(txt.indexOf(QLatin1Char('>')) + 1);
+            const QStringRef firstTag = txt.leftRef(txt.indexOf(QLatin1Char('>')) + 1);
             if (firstTag.startsWith(QLatin1String("<qt")) && firstTag.contains(QLatin1String("type")) && firstTag.contains(QLatin1String("detail"))) {
 #ifndef QT_NO_CURSOR
                 QApplication::restoreOverrideCursor();