Avoid -fsanitize=float-divide-by-zero

...after d51bc7b3813ccbdf41a50664d41b2fa3d25c6954 "PrintPreviewWindow dynamic
preview Bitmap", in CppunitTest_vcl_dialogs_test:

> vcl/source/window/printdlg.cxx:334:32: runtime error: division by zero
>  #0 in vcl::PrintDialog::PrintPreviewWindow::preparePreviewBitmap() at vcl/source/window/printdlg.cxx:334:32 (instdir/program/libvcllo.so +0x31ac6df)
>  #1 in vcl::PrintDialog::PrintPreviewWindow::Resize() at vcl/source/window/printdlg.cxx:144:5 (instdir/program/libvcllo.so +0x31ab3ae)
>  #2 in vcl::Window::ImplCallResize() at vcl/source/window/event.cxx:522:5 (instdir/program/libvcllo.so +0x2f546d1)
>  #3 in vcl::Window::ImplPosSizeWindow(long, long, long, long, PosSizeFlags) at vcl/source/window/window.cxx:1603:17 (instdir/program/libvcllo.so +0x34f2efc)
>  #4 in vcl::Window::setPosSizePixel(long, long, long, long, PosSizeFlags) at vcl/source/window/window.cxx:2831:18 (instdir/program/libvcllo.so +0x3524ca5)
>  #5 in vcl::Window::SetPosSizePixel(Point const&, Size const&) at vcl/source/window/window2.cxx:1313:5 (instdir/program/libvcllo.so +0x348582b)
>  #6 in VclContainer::setLayoutPosSize(vcl::Window&, Point const&, Size const&) at vcl/source/window/layout.cxx:57:13 (instdir/program/libvcllo.so +0x2f950fb)
>  #7 in VclContainer::setLayoutAllocation(vcl::Window&, Point const&, Size const&) at vcl/source/window/layout.cxx:68:9 (instdir/program/libvcllo.so +0x2f953e8)
>  #8 in VclBox::setAllocation(Size const&) at vcl/source/window/layout.cxx:486:13 (instdir/program/libvcllo.so +0x2f9ed9c)
>  #9 in VclContainer::SetPosSizePixel(Point const&, Size const&) at vcl/source/window/layout.cxx:147:9 (instdir/program/libvcllo.so +0x2f96795)
>  #10 in VclContainer::setLayoutPosSize(vcl::Window&, Point const&, Size const&) at vcl/source/window/layout.cxx:57:13 (instdir/program/libvcllo.so +0x2f950fb)
>  #11 in VclContainer::setLayoutAllocation(vcl::Window&, Point const&, Size const&) at vcl/source/window/layout.cxx:68:9 (instdir/program/libvcllo.so +0x2f953e8)
>  #12 in VclBox::setAllocation(Size const&) at vcl/source/window/layout.cxx:486:13 (instdir/program/libvcllo.so +0x2f9ed9c)
>  #13 in VclContainer::SetPosSizePixel(Point const&, Size const&) at vcl/source/window/layout.cxx:147:9 (instdir/program/libvcllo.so +0x2f96795)
>  #14 in VclContainer::setLayoutPosSize(vcl::Window&, Point const&, Size const&) at vcl/source/window/layout.cxx:57:13 (instdir/program/libvcllo.so +0x2f950fb)
>  #15 in VclContainer::setLayoutAllocation(vcl::Window&, Point const&, Size const&) at vcl/source/window/layout.cxx:68:9 (instdir/program/libvcllo.so +0x2f953e8)
>  #16 in VclBox::setAllocation(Size const&) at vcl/source/window/layout.cxx:486:13 (instdir/program/libvcllo.so +0x2f9ed9c)
>  #17 in VclContainer::SetPosSizePixel(Point const&, Size const&) at vcl/source/window/layout.cxx:147:9 (instdir/program/libvcllo.so +0x2f96795)
>  #18 in VclContainer::setLayoutPosSize(vcl::Window&, Point const&, Size const&) at vcl/source/window/layout.cxx:57:13 (instdir/program/libvcllo.so +0x2f950fb)
>  #19 in VclContainer::setLayoutAllocation(vcl::Window&, Point const&, Size const&) at vcl/source/window/layout.cxx:68:9 (instdir/program/libvcllo.so +0x2f953e8)
>  #20 in SystemWindow::setPosSizeOnContainee(Size, vcl::Window&) at vcl/source/window/syswin.cxx:1083:5 (instdir/program/libvcllo.so +0x3345d47)
>  #21 in SystemWindow::setOptimalLayoutSize() at vcl/source/window/syswin.cxx:1133:5 (instdir/program/libvcllo.so +0x3346d69)
>  #22 in SystemWindow::DoInitialLayout() at vcl/source/window/syswin.cxx:1145:9 (instdir/program/libvcllo.so +0x3347183)
>  #23 in Dialog::StateChanged(StateChangedType) at vcl/source/window/dialog.cxx:724:9 (instdir/program/libvcllo.so +0x2e49078)
>  #24 in vcl::Window::CompatStateChanged(StateChangedType) at vcl/source/window/window.cxx:3795:5 (instdir/program/libvcllo.so +0x3507fa6)
>  #25 in vcl::Window::ImplCallInitShow() at vcl/source/window/event.cxx:484:5 (instdir/program/libvcllo.so +0x2f53367)
>  #26 in vcl::Window::Show(bool, ShowFlags) at vcl/source/window/window.cxx:2294:13 (instdir/program/libvcllo.so +0x34fdeb9)
>  #27 in Dialog::createScreenshot() at vcl/source/window/dialog.cxx:973:5 (instdir/program/libvcllo.so +0x2e5239c)
>  #28 in ScreenshotTest::saveScreenshot(Dialog&) at test/source/screenshot_test.cxx:107:38 (workdir/LinkTarget/CppunitTest/../Library/libtest.so +0x11665a)
>  #29 in ScreenshotTest::dumpDialogToPath(Dialog&) at test/source/screenshot_test.cxx:176:9 (workdir/LinkTarget/CppunitTest/../Library/libtest.so +0x117e0c)
>  #30 in ScreenshotTest::dumpDialogToPath(rtl::OString const&) at test/source/screenshot_test.cxx:206:13 (workdir/LinkTarget/CppunitTest/../Library/libtest.so +0x118b34)
>  #31 in ScreenshotTest::processDialogBatchFile(rtl::OUString const&) at test/source/screenshot_test.cxx:264:17 (workdir/LinkTarget/CppunitTest/../Library/libtest.so +0x119d8d)
>  #32 in VclDialogsTest::openAnyDialog() at vcl/qa/unit/vcl-dialogs-test.cxx:59:5 (workdir/LinkTarget/CppunitTest/libtest_vcl_dialogs_test.so +0xf74b)
...

Change-Id: Ife158d466b012b44af1abf2b72eadd0ac4be3b7e
Reviewed-on: https://gerrit.libreoffice.org/52357
Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/vcl/source/window/printdlg.cxx b/vcl/source/window/printdlg.cxx
index d7124a15fc3b..23da5dd941d5 100644
--- a/vcl/source/window/printdlg.cxx
+++ b/vcl/source/window/printdlg.cxx
@@ -331,7 +331,7 @@ void PrintDialog::PrintPreviewWindow::preparePreviewBitmap()
     const double fPreviewSizeSquare(static_cast<double>(maPreviewBitmap.GetSizePixel().getWidth() * maPreviewBitmap.GetSizePixel().getHeight()));
 
     // test as equal up to 0.1% (0.001)
-    if(fabs((fScaledSizeSquare / fPreviewSizeSquare) - 1.0) < 0.001)
+    if(fPreviewSizeSquare == 0.0 || fabs((fScaledSizeSquare / fPreviewSizeSquare) - 1.0) < 0.001)
     {
         // maximum is reached, avoid bigger scaling
         return;