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

Conflicts:
	configure
5.7 now supports clang on android; but dev re-worked configure

	src/gui/kernel/qevent.h
One side renamed a parameter of a constructor; the other added an
alternate constructor on the next line.  Applied the rename to both
for consistency.

	tests/auto/tools/moc/tst_moc.cpp
Each side added a new test at the end.

	.qmake.conf
Ignored 5.7's change to MODULE_VERSION.

	configure.json
No conflict noticed by git; but changes in 5.7 were needed for the
re-worked configure to accommodate 5.7's stricter handling of C++11.

Change-Id: I9cda53836a32d7bf83828212c7ea00b1de3e09d2

1 files changed, 10 insertions, 5 deletions

diff --git a/src/gui/painting/qbackingstore.cpp b/src/gui/painting/qbackingstore.cpp
index 801397751b..e3d18512dd 100644
--- a/src/gui/painting/qbackingstore.cpp
+++ b/src/gui/painting/qbackingstore.cpp
@@ -236,11 +236,16 @@ QSize QBackingStore::size() const
 */
 bool QBackingStore::scroll(const QRegion &area, int dx, int dy)
 {
-    Q_UNUSED(area);
-    Q_UNUSED(dx);
-    Q_UNUSED(dy);
-
-    return d_ptr->platformBackingStore->scroll(QHighDpi::toNativeLocalRegion(area, d_ptr->window), QHighDpi::toNativePixels(dx, d_ptr->window), QHighDpi::toNativePixels(dy, d_ptr->window));
+    // Disable scrolling for non-integer scroll deltas. For this case
+    // the the existing rendered pixels can't be re-used, and we return
+    // false to signal that a repaint is needed.
+    const qreal nativeDx = QHighDpi::toNativePixels(qreal(dx), d_ptr->window);
+    const qreal nativeDy = QHighDpi::toNativePixels(qreal(dy), d_ptr->window);
+    if (qFloor(nativeDx) != nativeDx || qFloor(nativeDy) != nativeDy)
+        return false;
+
+    return d_ptr->platformBackingStore->scroll(QHighDpi::toNativeLocalRegion(area, d_ptr->window),
+                                               nativeDx, nativeDy);
 }
 
 /*!