tdf#158047 allow the tdf#157635 fix for palettes with 64 entries

Change-Id: Ib4e4deb5f7e332a7ef3a9231e993231068c21c4f
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/158885
Tested-by: Jenkins
Reviewed-by: Noel Grandin <noel.grandin@collabora.co.uk>
Reviewed-by: Patrick Luby <plubius@neooffice.org>
diff --git a/vcl/source/filter/igif/gifread.cxx b/vcl/source/filter/igif/gifread.cxx
index 78d3190..cac966c 100644
--- a/vcl/source/filter/igif/gifread.cxx
+++ b/vcl/source/filter/igif/gifread.cxx
@@ -319,8 +319,6 @@ void GIFReader::ReadPaletteEntries( BitmapPalette* pPal, sal_uLong nCount )
        rColor.SetBlue( *pTmp++ );
    }

    bEnhance = false;

    // if possible accommodate some standard colours
    if( nCount < 256 )
    {
@@ -329,15 +327,13 @@ void GIFReader::ReadPaletteEntries( BitmapPalette* pPal, sal_uLong nCount )
        if( nCount < 255 )
            (*pPal)[ 254UL ] = COL_BLACK;
    }
    else
    {
        // tdf#157793 limit tdf#157635 fix to only larger palettes
        // I don't know why, but the fix for tdf#157635 causes
        // images with a palette of 16 entries to be inverted.
        // Is this the only condition for masking out black
        // pixels in non-transparent animation frames?
        bEnhance = true;
    }

    // tdf#157793 limit tdf#157635 fix to only larger palettes
    // I don't know why, but the fix for tdf#157635 causes
    // images with a palette of 16 entries to be inverted.
    // Also, fix tdf#158047 by allowing the tdf#157635 fix for
    // palettes with 64 entries.
    bEnhance = (nCount > 16);
}

bool GIFReader::ReadExtension()