handle empty tools::Rectangle in vcl

Change-Id: I64b5c3c5a19408febe7753db6ea403b91f7f5c83
Reviewed-on: https://gerrit.libreoffice.org/72188
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>

vcl/source/control/tabctrl.cxx

@@ -544,11 +544,13 @@ tools::Rectangle TabControl::ImplGetTabRect( sal_uInt16 nItemPos, long nWidth, l
             nLastPos = 0;
 
         tools::Rectangle aRect = ImplGetTabRect( nLastPos, nWidth, nHeight );
+        if (aRect.IsEmpty())
+            return aRect;
         long nW = nWidth-TAB_OFFSET*2;
         long nH = nHeight-aRect.Bottom()-TAB_OFFSET*2;
         aRect = (nW > 0 && nH > 0)
-        ? tools::Rectangle( Point( TAB_OFFSET, aRect.Bottom()+TAB_OFFSET ), Size( nW, nH ) )
-        : tools::Rectangle();
+            ? tools::Rectangle( Point( TAB_OFFSET, aRect.Bottom()+TAB_OFFSET ), Size( nW, nH ) )
+            : tools::Rectangle();
         return aRect;
     }
 

vcl/source/filter/wmf/emfwr.cxx

@@ -607,11 +607,13 @@ void EMFWriter::ImplWriteSize( const Size& rSize)
 void EMFWriter::ImplWriteRect( const tools::Rectangle& rRect )
 {
     const tools::Rectangle aRect( OutputDevice::LogicToLogic ( rRect, maVDev->GetMapMode(), maDestMapMode ));
+    auto right = aRect.IsWidthEmpty() ? aRect.Left() : aRect.Right();
+    auto bottom = aRect.IsHeightEmpty() ? aRect.Top() : aRect.Bottom();
     m_rStm
        .WriteInt32( aRect.Left() )
        .WriteInt32( aRect.Top() )
-       .WriteInt32( aRect.Right() )
-       .WriteInt32( aRect.Bottom() );
+       .WriteInt32( right )
+       .WriteInt32( bottom );
 }
 
 void EMFWriter::ImplWritePolygonRecord( const tools::Polygon& rPoly, bool bClose )

vcl/source/outdev/map.cxx

@@ -1863,10 +1863,14 @@ tools::Rectangle OutputDevice::LogicToLogic( const tools::Rectangle& rRectSource
     {
         ENTER3( eUnitSource, eUnitDest );
 
-        return tools::Rectangle( fn3( rRectSource.Left(), nNumerator, nDenominator ),
-                          fn3( rRectSource.Top(), nNumerator, nDenominator ),
-                          fn3( rRectSource.Right(), nNumerator, nDenominator ),
-                          fn3( rRectSource.Bottom(), nNumerator, nDenominator ) );
+        auto left = fn3( rRectSource.Left(), nNumerator, nDenominator );
+        auto top = fn3( rRectSource.Top(), nNumerator, nDenominator );
+        if (rRectSource.IsEmpty())
+            return tools::Rectangle( left, top );
+
+        auto right = fn3( rRectSource.Right(), nNumerator, nDenominator );
+        auto bottom = fn3( rRectSource.Bottom(), nNumerator, nDenominator );
+        return tools::Rectangle(left, top, right, bottom);
     }
     else
     {

vcl/unx/gtk3/gtk3salnativewidgets-gtk.cxx

@@ -731,15 +731,19 @@ void GtkSalGraphics::PaintScrollbar(GtkStyleContext *context,
         {
             tools::Rectangle aBtn1Rect = NWGetScrollButtonRect(ControlPart::ButtonLeft, aTrackRect);
             tools::Rectangle aBtn2Rect = NWGetScrollButtonRect(ControlPart::ButtonRight, aTrackRect);
-            aTrackRect.SetLeft( aBtn1Rect.Right() );
-            aTrackRect.SetRight( aBtn2Rect.Left() );
+            if (!aBtn1Rect.IsWidthEmpty())
+                aTrackRect.SetLeft( aBtn1Rect.Right() );
+            if (!aBtn2Rect.IsWidthEmpty())
+                aTrackRect.SetRight( aBtn2Rect.Left() );
         }
         else
         {
             tools::Rectangle aBtn1Rect = NWGetScrollButtonRect(ControlPart::ButtonUp, aTrackRect);
             tools::Rectangle aBtn2Rect = NWGetScrollButtonRect(ControlPart::ButtonDown, aTrackRect);
-            aTrackRect.SetTop( aBtn1Rect.Bottom() + 1 );
-            aTrackRect.SetBottom( aBtn2Rect.Top() );
+            if (!aBtn1Rect.IsHeightEmpty())
+                aTrackRect.SetTop( aBtn1Rect.Bottom() + 1 );
+            if (!aBtn2Rect.IsHeightEmpty())
+                aTrackRect.SetBottom( aBtn2Rect.Top() );
         }
 
         GtkStyleContext* pScrollbarTroughStyle = scrollbarOrientation == GTK_ORIENTATION_VERTICAL ?