vcl: tdf#98812: acquire reference count of WinFontInstances

... when they are inserted in WinSalGraphics::mpWinFontEntry.

Not sure why one of these drops to 0 but is not removed from the
WinSalGraphics when formatting this particular bugdoc.

Acquiring the instances when retaining pointers to them should make
the life cycle a little less insane.

Change-Id: If1404f46a13736b2a226e198bdf0c3ca8e09bb38

3 files changed, 20 insertions, 0 deletions

diff --git a/vcl/inc/win/salgdi.h b/vcl/inc/win/salgdi.h
index a889b45dca27..ffd83ab251ad 100644
--- a/vcl/inc/win/salgdi.h
+++ b/vcl/inc/win/salgdi.h
@@ -219,6 +219,8 @@ private:
     sal_uIntPtr             mnFontKernPairCount;// Number of Kerning Pairs of the current Font
     int                     mnPenWidth;         // Linienbreite
 
+    LogicalFontInstance* GetWinFontEntry(int nFallbackLevel);
+
 public:
     HDC getHDC() const { return mhLocalDC; }
     void setHDC(HDC aNew) { mhLocalDC = aNew; }
diff --git a/vcl/win/gdi/salfont.cxx b/vcl/win/gdi/salfont.cxx
index 3278e888ecf2..0485eaf0c34d 100644
--- a/vcl/win/gdi/salfont.cxx
+++ b/vcl/win/gdi/salfont.cxx
@@ -1442,12 +1442,23 @@ sal_uInt16 WinSalGraphics::SetFont( FontSelectPattern* pFont, int nFallbackLevel
             if( mhFonts[i] )
                 ::DeleteFont( mhFonts[i] );
             mhFonts[ i ] = 0;
+            if (mpWinFontEntry[i])
+            {
+                GetWinFontEntry(i)->mpFontCache->Release(GetWinFontEntry(i));
+            }
+            mpWinFontEntry[i] = nullptr;
+            mpWinFontData[i] = nullptr;
         }
         mhDefFont = 0;
         return 0;
     }
 
     DBG_ASSERT( pFont->mpFontData, "WinSalGraphics mpFontData==NULL");
+    if (mpWinFontEntry[nFallbackLevel])
+    {
+        GetWinFontEntry(nFallbackLevel)->mpFontCache->Release(GetWinFontEntry(nFallbackLevel));
+    }
+    pFont->mpFontInstance->mpFontCache->Acquire(pFont->mpFontInstance);
     mpWinFontEntry[ nFallbackLevel ] = reinterpret_cast<WinFontInstance*>( pFont->mpFontInstance );
     mpWinFontData[ nFallbackLevel ] = static_cast<const WinFontFace*>( pFont->mpFontData );
 
@@ -1470,6 +1481,7 @@ sal_uInt16 WinSalGraphics::SetFont( FontSelectPattern* pFont, int nFallbackLevel
                 ::DeleteFont( mhFonts[i] );
                 mhFonts[i] = 0;
             }
+            // note: removing mpWinFontEntry[i] here has obviously bad effects
         }
     }
 
diff --git a/vcl/win/gdi/winlayout.cxx b/vcl/win/gdi/winlayout.cxx
index e073a01941c2..65ebbdd4b152 100644
--- a/vcl/win/gdi/winlayout.cxx
+++ b/vcl/win/gdi/winlayout.cxx
@@ -1362,6 +1362,7 @@ WinLayout::WinLayout(HDC hDC, const WinFontFace& rWFD, WinFontInstance& rWFE, bo
     mrWinFontData( rWFD ),
     mrWinFontEntry(rWFE)
 {
+    assert(mrWinFontEntry.mnRefCount > 0);
     // keep mrWinFontEntry alive
     mrWinFontEntry.mpFontCache->Acquire(&mrWinFontEntry);
 }
@@ -4288,6 +4289,11 @@ int    WinSalGraphics::GetMinKashidaWidth()
     return nMinKashida;
 }
 
+LogicalFontInstance * WinSalGraphics::GetWinFontEntry(int const nFallbackLevel)
+{
+    return mpWinFontEntry[nFallbackLevel];
+}
+
 WinFontInstance::WinFontInstance( FontSelectPattern& rFSD )
 :   LogicalFontInstance( rFSD )
 ,    mpKerningPairs( NULL )