Add SAL_FALLTHROUGH, where apparently appropriate

Change-Id: I796ec3b79d7c26d9efe275b4232ae85cac80b578

vcl/source/filter/graphicfilter2.cxx

@@ -876,6 +876,7 @@ bool GraphicDescriptor::ImpDetectPSD( SvStream& rStm, bool bExtendedInfo )
                         case 4 :
                         case 3 :
                             nBitsPerPixel = 24;
+                            SAL_FALLTHROUGH;
                         case 2 :
                         case 1 :
                             aPixSize.Width() = nColumns;

vcl/source/filter/sgvspln.cxx

@@ -426,16 +426,19 @@ sal_uInt16 NaturalSpline(sal_uInt16 n, double* x, double* y,
                 c[0]  =c[0]-h[0];
                 b[n-2]=b[n-2]-h[n-1];
             }
+            SAL_FALLTHROUGH;
         }
         case 1: {
             a[0]  =a[0]-1.5*((y[1]-y[0])/h[0]-Marg0);
             a[n-2]=a[n-2]-1.5*(MargN-(y[n]-y[n-1])/h[n-1]);
             d[0]  =d[0]-h[0]*0.5;
             d[n-2]=d[n-2]-h[n-1]*0.5;
+            SAL_FALLTHROUGH;
         }
         case 2: {
             a[0]  =a[0]-h[0]*Marg0*0.5;
             a[n-2]=a[n-2]-h[n-1]*MargN*0.5;
+            SAL_FALLTHROUGH;
         }
         case 3: {
             a[0]  =a[0]+Marg0*h[0]*h[0]*0.5;
@@ -460,16 +463,19 @@ sal_uInt16 NaturalSpline(sal_uInt16 n, double* x, double* y,
                 c[0]=c[1]+h[0]*(c[1]-c[2])/h[1];
                 c[n]=c[n-1]+h[n-1]*(c[n-1]-c[n-2])/h[n-2];
             }
+            SAL_FALLTHROUGH;
         }
         case 1: {
             c[0]=1.5*((y[1]-y[0])/h[0]-Marg0);
             c[0]=(c[0]-c[1]*h[0]*0.5)/h[0];
             c[n]=1.5*((y[n]-y[n-1])/h[n-1]-MargN);
             c[n]=(c[n]-c[n-1]*h[n-1]*0.5)/h[n-1];
+            SAL_FALLTHROUGH;
         }
         case 2: {
             c[0]=Marg0*0.5;
             c[n]=MargN*0.5;
+            SAL_FALLTHROUGH;
         }
         case 3: {
             c[0]=c[1]-Marg0*h[0]*0.5;

vcl/source/filter/wmf/enhwmf.cxx

@@ -954,12 +954,14 @@ bool EnhWMFReader::ReadEnhWMF()
                                     aLineInfo.SetLineCap( css::drawing::LineCap_ROUND );
                                     break;
                                 }
+                                SAL_FALLTHROUGH;
                             case PS_ENDCAP_SQUARE :
                                 if ( aSize.Width() )
                                 {
                                     aLineInfo.SetLineCap( css::drawing::LineCap_SQUARE );
                                     break;
                                 }
+                                SAL_FALLTHROUGH;
                             case PS_ENDCAP_FLAT :
                             default :
                                 aLineInfo.SetLineCap( css::drawing::LineCap_BUTT );
@@ -1042,12 +1044,14 @@ bool EnhWMFReader::ReadEnhWMF()
                                     aLineInfo.SetLineCap( css::drawing::LineCap_ROUND );
                                     break;
                                 }
+                                SAL_FALLTHROUGH;
                             case PS_ENDCAP_SQUARE :
                                 if ( aLineInfo.GetWidth() )
                                 {
                                     aLineInfo.SetLineCap( css::drawing::LineCap_SQUARE );
                                     break;
                                 }
+                                SAL_FALLTHROUGH;
                             case PS_ENDCAP_FLAT :
                             default :
                                 aLineInfo.SetLineCap( css::drawing::LineCap_BUTT );
@@ -1168,6 +1172,7 @@ bool EnhWMFReader::ReadEnhWMF()
 
                 case EMR_ABORTPATH :
                     pOut->ClearPath();
+                    SAL_FALLTHROUGH;
                 case EMR_ENDPATH :
                     bRecordPath = false;
                 break;
@@ -1527,6 +1532,7 @@ bool EnhWMFReader::ReadEnhWMF()
 
                 case EMR_EXTTEXTOUTA :
                     bFlag = true;
+                    SAL_FALLTHROUGH;
                 case EMR_EXTTEXTOUTW :
                 {
                     sal_Int32   nLeft, nTop, nRight, nBottom, ptlReferenceX, ptlReferenceY, nGfxMode, nXScale, nYScale;

vcl/source/gdi/pngread.cxx

@@ -570,6 +570,7 @@ bool PNGReaderImpl::ImplReadHeader( const Size& rPreviewSizeHint )
             {
                 case 16 :
                     mnTargetDepth = 8;  // we have to reduce the bitmap
+                    SAL_FALLTHROUGH;
                 case 8 :
                     mbGrayScale = true;
                     break;

vcl/unx/kde4/KDESalGraphics.cxx

@@ -694,6 +694,7 @@ bool KDESalGraphics::getNativeControlRegion( ControlType type, ControlPart part,
 
                 break;
             }
+            SAL_FALLTHROUGH;
         case CTRL_COMBOBOX:
         case CTRL_LISTBOX:
         {