DirectFB: Improvement for QDirectFBPaintEngine::fill()

Improvement for bug fix related to QTBUG-23850 in QDirectFBPaintEngine:
combine the conditions for an accelerated fillrect (5 elements and
rectangle shape) in first if-statement.
The previous check for NULL pointer solves the problem for the crash,
but it simply skips the type check (which caused the crash before) and
the or-condition (shape) became true and leads to an accelerated
fillrect. Otherwise it would fallback to raster.
The original reason for the crash (elemets is null) might be
Q_DISABLE_COPY macro of QVectorPath, especially with the last lines of
the Q_DISABLE_COPY documentation, which could become true on embedded
devices, where DirectFB is often used, with special
toolchains/compilers.

Task-number: QTBUG-23850
Change-Id: I340291fbce24260c7522684305c292e66cfc32af
Reviewed-by: Girish Ramakrishnan <girish.1.ramakrishnan@nokia.com>

1 files changed, 9 insertions, 12 deletions

diff --git a/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp b/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
index 2af6f3d..d28918c 100644
--- a/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
+++ b/src/plugins/gfxdrivers/directfb/qdirectfbpaintengine.cpp
@@ -825,18 +825,15 @@ void QDirectFBPaintEngine::fill(const QVectorPath &path, const QBrush &brush)
     if (brush.style() == Qt::NoBrush)
         return;
 
-    const QPainterPath::ElementType *elements = path.elements();
-    const qreal                     *points   = path.points();
-
-    if (path.elementCount() == 5) {
-        if ((elements
-            && elements[0] == QPainterPath::MoveToElement
-            && elements[1] == QPainterPath::LineToElement
-            && elements[2] == QPainterPath::LineToElement
-            && elements[3] == QPainterPath::LineToElement
-            && elements[4] == QPainterPath::LineToElement )
-                || (path.shape() == QVectorPath::RectangleHint)) {
-
+    if (path.elementCount() == 5 && path.shape() == QVectorPath::RectangleHint) {
+        const QPainterPath rectPath = path.convertToPainterPath();
+        if (rectPath.elementAt(0).type == QPainterPath::MoveToElement
+            && rectPath.elementAt(1).type == QPainterPath::LineToElement
+            && rectPath.elementAt(2).type == QPainterPath::LineToElement
+            && rectPath.elementAt(3).type == QPainterPath::LineToElement
+            && rectPath.elementAt(4).type == QPainterPath::LineToElement) {
+
+            const qreal *points = path.points();
             if (points[1] == points[3]
                 && points[2] == points[4]
                 && points[5] == points[7]