Don’t abuse glyph id for flagging dropped glyphs

Use a bitflag instead.

Change-Id: I7833a37578112b5326f4a30578596e53085ff3c0
Reviewed-on: https://gerrit.libreoffice.org/53269Tested-by: Jenkins <ci@libreoffice.org>
Reviewed-by: Khaled Hosny <khaledhosny@eglug.org>

vcl/inc/sallayout.hxx

@@ -286,7 +286,8 @@ public:
         IS_DIACRITIC  = 0x004,
         IS_VERTICAL   = 0x008,
         IS_SPACING    = 0x010,
-        ALLOW_KASHIDA = 0x020
+        ALLOW_KASHIDA = 0x020,
+        IS_DROPPED    = 0x040
     };
 
     bool    IsClusterStart() const  { return ((mnFlags & IS_IN_CLUSTER) == 0); }
@@ -295,6 +296,7 @@ public:
     bool    IsVertical() const      { return ((mnFlags & IS_VERTICAL) != 0); }
     bool    IsSpacing() const       { return ((mnFlags & IS_SPACING) != 0); }
     bool    AllowKashida() const    { return ((mnFlags & ALLOW_KASHIDA) != 0); }
+    bool    IsDropped() const       { return ((mnFlags & IS_DROPPED) != 0); }
 };
 
 class VCL_PLUGIN_PUBLIC GenericSalLayout : public SalLayout

vcl/source/gdi/sallayout.cxx

@@ -47,7 +47,6 @@
 // Glyph Flags
 #define GF_FONTMASK  0xF0000000
 #define GF_FONTSHIFT 28
-#define GF_DROPPED   0xFFFFFFFF
 
 
 std::ostream &operator <<(std::ostream& s, ImplLayoutArgs const &rArgs)
@@ -1003,19 +1002,19 @@ void GenericSalLayout::DropGlyph( int nStart )
 
     std::vector<GlyphItem>::iterator pGlyphIter = m_GlyphItems.begin();
     pGlyphIter += nStart;
-    pGlyphIter->maGlyphId = GF_DROPPED;
     pGlyphIter->mnCharPos = -1;
+    pGlyphIter->mnFlags |= GlyphItem::IS_DROPPED;
 }
 
 void GenericSalLayout::Simplify( bool bIsBase )
 {
-    const sal_GlyphId nDropMarker = bIsBase ? GF_DROPPED : 0;
-
     // remove dropped glyphs inplace
     size_t j = 0;
     for(size_t i = 0; i < m_GlyphItems.size(); i++ )
     {
-        if( m_GlyphItems[i].maGlyphId == nDropMarker )
+        if (bIsBase && m_GlyphItems[i].IsDropped())
+            continue;
+        if (!bIsBase && m_GlyphItems[i].maGlyphId == 0)
             continue;
 
         if( i != j )