vcl: fix resource management issue in WinSalLayout

Since commit 65a66d41 the
sd_exports_test crashes on Windows in UniscribeLayout because
it uses a ImplFontEntry that has been removed from the font cache.

Tweak the refcount in WinLayout so it will be valid.

Change-Id: Ic4bf984ea9fd70de9fa95ca964ae12d95d47d5bf
(cherry picked from commit 34700400)
Reviewed-on: https://gerrit.libreoffice.org/18121Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

vcl/inc/outfont.hxx

@@ -36,6 +36,7 @@ class PhysicalFontFamily;
 class ImplGetDevFontList;
 class ImplGetDevSizeList;
 class ImplFontEntry;
+class ImplFontCache;
 class ImplPreMatchFontSubstitution;
 class ImplGlyphFallbackFontSubstitution;
 class FontSelectPattern;
@@ -227,6 +228,7 @@ public:
     virtual             ~ImplFontEntry();
 
 public: // TODO: make data members private
+    ImplFontCache * m_pFontCache;
     FontSelectPattern  maFontSelData;      // FontSelectionData
     ImplFontMetricData  maMetric;           // Font Metric
     const ConvertChar*  mpConversion;       // used e.g. for StarBats->StarSymbol

vcl/source/outdev/font.cxx

@@ -970,7 +970,8 @@ vcl::Font OutputDevice::GetDefaultFont( DefaultFontType nType, LanguageType eLan
 }
 
 ImplFontEntry::ImplFontEntry( const FontSelectPattern& rFontSelData )
-    : maFontSelData( rFontSelData )
+    : m_pFontCache(nullptr)
+    , maFontSelData( rFontSelData )
     , maMetric( rFontSelData )
     , mpConversion( NULL )
     , mnLineHeight( 0 )
@@ -987,6 +988,7 @@ ImplFontEntry::ImplFontEntry( const FontSelectPattern& rFontSelData )
 ImplFontEntry::~ImplFontEntry()
 {
     delete mpUnicodeFallbackList;
+    m_pFontCache = nullptr;
 }
 
 size_t ImplFontEntry::GFBCacheKey_Hash::operator()( const GFBCacheKey& rData ) const
@@ -1322,6 +1324,7 @@ ImplFontEntry* ImplFontCache::GetFontEntry( PhysicalFontCollection* pFontList,
     {
         // create a new logical font instance from this physical font face
         pEntry = pFontData->CreateFontInstance( aFontSelData );
+        pEntry->m_pFontCache = this;
 
         // if we're subtituting from or to a symbol font we may need a symbol
         // conversion table

vcl/win/source/gdi/winlayout.cxx

@@ -29,6 +29,7 @@
 #include <vcl/opengl/OpenGLHelper.hxx>
 #include <win/salgdi.h>
 #include <win/saldata.hxx>
+#include <outdev.h>
 
 #include "sft.hxx"
 #include "sallayout.hxx"
@@ -453,7 +454,14 @@ WinLayout::WinLayout(HDC hDC, const ImplWinFontData& rWFD, ImplWinFontEntry& rWF
     mrWinFontData( rWFD ),
     mrWinFontEntry(rWFE),
     mbUseOpenGL(bUseOpenGL)
-{}
+{
+    ++mrWinFontEntry.mnRefCount; // keep it alive
+}
+
+WinLayout::~WinLayout()
+{
+    mrWinFontEntry.m_pFontCache->Release(&mrWinFontEntry);
+}
 
 void WinLayout::InitFont() const
 {

vcl/win/source/gdi/winlayout.hxx

@@ -41,6 +41,7 @@ class WinLayout : public SalLayout
 {
 public:
                         WinLayout(HDC, const ImplWinFontData&, ImplWinFontEntry&, bool bUseOpenGL);
+    virtual             ~WinLayout();
     virtual void        InitFont() const SAL_OVERRIDE;
     void                SetFontScale( float f ) { mfFontScale = f; }
     HFONT               DisableFontScaling() const;