The '- 1's had been like that ever since
cbd8e4d1 "added VisibleArea and MapUnit
properties" but caused the following problem, suggesting that they may have been
an off-by-one error right from the start:

Opening an .odt Writer doc with an embedded (via "Insert - Object - OLE
Object... - Create new - LibreOffice 5.3 Presentation") Impress doc for which
the .odt's content.xml records

  <draw:frame ... svg:width="5.5508in" svg:height="3.9366in" ...>

causes XMLTextFrameContext_Impl::Create
(xmloff/source/text/XMLTextFrameContext.cxx) to create a size (in 100th mm?) of
14099x9999, which is converted to 7993x5669 twips, which are then passed to an
SwFormatFrameSize ctor (sw/source/core/layout/atrfrm.cxx).

However, double-clicking into the Writer doc's Impress area (to make the Impress
doc editable) and then clicking back into the outer Writer doc's area (to put
the Impress doc back into non-editing mode) causes the Writer doc to be
considered modified (e.g., the "Save" icon gets a small green "plus" overlay)
due to the call to SfxObjectShell::SetModified at

> SfxObjectShell::SetModified(bool) (this=0x21293a0, bModifiedP=true) at sfx2/source/doc/objmisc.cxx:314
> SwDocShell::SetModified(bool) (this=0x21293a0, bSet=true) at sw/source/uibase/app/docsh2.cxx:1243
> SwDocShell::Ole2ModifiedHdl(bool) (this=0x21293a0, bNewStatus=true) at sw/source/uibase/app/docsh.cxx:1093
> SwDocShell::LinkStubOle2ModifiedHdl(void*, bool) (instance=0x21293a0, data=true) at sw/source/uibase/app/docsh.cxx:1090
> Link<bool, void>::Call(bool) const (this=0xa32c0c8, data=true) at include/tools/link.hxx:84
> sw::DocumentStateManager::SetModified() (this=0x82e77f0) at sw/source/core/doc/DocumentStateManager.cxx:48
> SwDoc::SetAttr(SfxItemSet const&, SwFormat&) (this=0xa32c050, rSet=SfxItemSet of pool 0x21dbd60 with parent 0x0 and Which ranges: [(88, 88)] = {...}, rFormat=...) at sw/source/core/doc/docfmt.cxx:492
> SwDoc::SetAttr(SfxPoolItem const&, SwFormat&) (this=0xa32c050, rAttr=..., rFormat=...) at sw/source/core/doc/docfmt.cxx:468
> SwFlyFrame::ChgSize(Size const&) (this=0xa14ae10, aNewSize=Size = {...}) at sw/source/core/layout/fly.cxx:1993
> SwFEShell::RequestObjectResize(SwRect const&, com::sun::star::uno::Reference<com::sun::star::embed::XEmbeddedObject> const&) (this=0x83fc880, rRect=SwRect = {...}, xObj=uno::Reference to (OCommonEmbeddedObject *) 0x7fff745f7530) at sw/source/core/frmedt/fefly1.cxx:1334
> SwOleClient::ViewChanged() (this=0x4a15a10) at sw/source/uibase/uiview/swcli.cxx:151
> SfxInPlaceClient::Invalidate() (this=0x4a15a10) at sfx2/source/view/ipclient.cxx:812
> SfxInPlaceClient::SetObjAreaAndScale(Rectangle const&, Fraction const&, Fraction const&) (this=0x4a15a10, rArea=Rectangle = {...}, rScaleWidth=Fraction containing std::unique_ptr<Fraction::Impl> containing 0x1d47a40, rScaleHeight=Fraction containing std::unique_ptr<Fraction::Impl> containing 0x8c0d910) at sfx2/source/view/ipclient.cxx:785
> SwWrtShell::CalcAndSetScale(svt::EmbeddedObjectRef&, SwRect const*, SwRect const*, bool) (this=0x83fc880, xObj=..., pFlyPrtRect=0x0, pFlyFrameRect=0x0, bNoTextFramePrtAreaChanged=false) at sw/source/uibase/wrtsh/wrtsh1.cxx:825
> SwWrtShell::LaunchOLEObj(long) (this=0x83fc880, nVerb=0) at sw/source/uibase/wrtsh/wrtsh1.cxx:591
> SwEditWin::MouseButtonDown(MouseEvent const&) (this=0x490b2e0, _rMEvt=...) at sw/source/uibase/docvw/edtwin.cxx:3366
> ImplHandleMouseEvent(VclPtr<vcl::Window> const&, MouseNotifyEvent, bool, long, long, unsigned long, unsigned short, MouseEventModifiers) (xWindow=..., nSVEvent=MouseNotifyEvent::MOUSEBUTTONDOWN, bMouseLeave=false, nX=750, nY=341, nMsgTime=32828148, nCode=1, nMode=(MouseEventModifiers::SIMPLECLICK | MouseEventModifiers::SELECT)) at vcl/source/window/winproc.cxx:698
> ImplHandleSalMouseButtonDown(vcl::Window*, SalMouseEvent*) (pWindow=0x19d19a0, pEvent=0x7fffffffc928) at vcl/source/window/winproc.cxx:1999
> ImplWindowFrameProc(vcl::Window*, SalEvent, void const*) (_pWindow=0x19d19a0, nEvent=SalEvent::MouseButtonDown, pEvent=0x7fffffffc928) at vcl/source/window/winproc.cxx:2329
> SalFrame::CallCallback(SalEvent, void const*) const (this=0x1996820, nEvent=SalEvent::MouseButtonDown, pEvent=0x7fffffffc928) at vcl/inc/salframe.hxx:280
> GtkSalFrame::CallCallbackExc(SalEvent, void const*) const (this=0x1996820, nEvent=SalEvent::MouseButtonDown, pEvent=0x7fffffffc928) at vcl/unx/gtk3/gtk3gtkframe.cxx:4219
> GtkSalFrame::signalButton(_GtkWidget*, _GdkEventButton*, void*) (pEvent=0x16403d0, frame=0x1996820) at vcl/unx/gtk3/gtk3gtkframe.cxx:2615
> <emit signal ??? on instance ???> (instance=instance@entry=0x16f0e20, signal_id=<optimized out>, detail=detail@entry=0) at gsignal.c:3441
> gtk_widget_event_internal (widget=0x16f0e20, event=0x16403d0) at gtkwidget.c:7731
> propagate_event (topmost=<optimized out>, event=<optimized out>, widget=0x16f0e20) at gtkmain.c:2545
> propagate_event (widget=<optimized out>, event=0x16403d0, captured=<optimized out>, topmost=0x0) at gtkmain.c:2647
> gtk_main_do_event (event=0x16403d0) at gtkmain.c:1878
> _gdk_event_emit (event=event@entry=0x16403d0) at gdkevents.c:73
> gdk_event_source_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at gdkeventsource.c:367
> g_main_context_dispatch (context=0x63a520) at gmain.c:3154
> g_main_context_dispatch (context=context@entry=0x63a520) at gmain.c:3769
> g_main_context_iterate (context=context@entry=0x63a520, block=block@entry=0, dispatch=dispatch@entry=1, self=<optimized out>) at gmain.c:3840
> g_main_context_iteration (context=0x63a520, may_block=0) at gmain.c:3901
> GtkData::Yield(bool, bool) (this=0x73e260, bWait=false, bHandleAllCurrentEvents=false) at vcl/unx/gtk3/gtk3gtkdata.cxx:479
> GtkInstance::DoYield(bool, bool, unsigned long) (this=0x73e3c0, bWait=false, bHandleAllCurrentEvents=false, nReleased=0) at vcl/unx/gtk3/../gtk/gtkinst.cxx:423
> ImplYield(bool, bool, unsigned long) (i_bWait=false, i_bAllEvents=false, nReleased=0) at vcl/source/app/svapp.cxx:504
> Application::Yield() () at vcl/source/app/svapp.cxx:551
> Application::Execute() () at vcl/source/app/svapp.cxx:468
> desktop::Desktop::DoExecute() () at desktop/source/app/app.cxx:1367
> desktop::Desktop::Main() (this=0x7fffffffe1e8) at desktop/source/app/app.cxx:1694
> ImplSVMain() () at vcl/source/app/svmain.cxx:185
> SVMain() () at vcl/source/app/svmain.cxx:223
> soffice_main() () at desktop/source/app/sofficemain.cxx:165
> sal_main () at desktop/source/app/main.c:48
> main (argc=1, argv=0x7fffffffe528) at desktop/source/app/main.c:47

because OCommonEmbeddedObject::getVisualAreaSize
(embeddedobj/source/commonembedding/visobj.cxx, called from
SwOleClient::ViewChanged, sw/source/uibase/uiview/swcli.cxx, ultimately
returning the value 14098x9998 calculated in
SdXImpressDocument::setPropertyValue, converted to twips) reports a size of
7993x5668 twips instead.

Change-Id: I8056b99b036970e308a89937b95c57996a8e7c79