Crash in QGLContextPrivate::bindTexture() when using QPainter::fillRect() with a brush having a size > max_texture_size

This crash originates from Maemo: https://projects.maemo.org/bugzilla/show_bug.cgi?id=248298

When rendering with an image > max_texture_size, the application crashes.
Stack trace:
Signal 11 (SIGSEGV)
0 QGLContextPrivate::bindTexture (this=0x1f8ba900, target=3553) at
qgl.cpp:2587
1 0x3d4dd774 QGL2PaintEngineExPrivate::updateBrushTexture
(this=0x1f932a58) at gl2paintengineex/qpaintengineex_opengl2.cpp:235
2 0x3d4e14a4 QGL2PaintEngineExPrivate::prepareForDraw (this=0x0,
srcPixelsAreOpaque=false) at gl2paintengineex/qpaintengineex_opengl2.cpp:1047
3 0x3d4e2ad8 QGL2PaintEngineExPrivate::fill (this=0x1f932a58) at
gl2paintengineex/qpaintengineex_opengl2.cpp:708
4 0x3c2dbf14 QPaintEngineEx::fillRect (this=0x0) at
painting/qpaintengineex.cpp:698
5 0x3c2ef724 QPainter::fillRect (this=0xaefe40ec) at
painting/qpainter.cpp:6934
6 0x3b89b510 WebCore::Image::drawPattern (this=0x42c2a3a8,
ctxt=0xaefe181c) at .../../WebCore/platform/graphics/qt/ImageQt.cpp:116
7 0x3b73bba8 WebCore::Image::drawTiled (this=0x42c2a3a8) at
.../../WebCore/platform/graphics/Image.cpp:142
8 0x3b7390ac WebCore::GraphicsContext::drawTiledImage (this=0xaefe181c,
image=0x42c2a3a8) at .../../WebCore/platform/graphics/GraphicsContext.cpp:422
9 0x3b7dc7b4 WebCore::RenderBoxModelObject::paintFillLayerExtended
(this=0x42c505a0, bgLayer=0x42cd0444, tx=0, ty=0, w=660, h=199, box=0x0,
backgroundObject=0x42c506d0) at
.../../WebCore/rendering/RenderBoxModelObject.cpp:618
10 0x3b7d0888 WebCore::RenderBox::paintFillLayer (this=0x0,
fillLayer=0x1fd60bf8, tx=0, ty=0, width=660, height=199,
backgroundObject=0x42c506d0) at .../../WebCore/rendering/RenderBox.cpp:775

The following code of QGL2PaintEngineExPrivate::updateBrushTexture() seems to be the problem:
if (currentBrushPixmap.width() > max_texture_size || currentBrushPixmap.height() > max_texture_size)
currentBrushPixmap = currentBrushPixmap.scaled(max_texture_size, max_texture_size, Qt::KeepAspectRatio);
It returns a null QPixmap instead of a valid pixmap. When the pixmap data is used later in the stack, it happily crashes.

The attached file is a reduction to reproduce the crash (on device).