compile error in main/vcl/unx/headless/svptext.cxx

[Don Lewis <tr...@apache.org>]

A while back FreeBSD upgraded to Clang 6.0 which defaults to C++14
instead of GNU++98/C++98 like earlier versions of Clang and GCC.
This triggered some new compile errors in the OpenOffice source
that probably had just previously been warnings.

One of the new errors was a integer constant getting assigned to a
pointer in SvpGlyphPeer::RemovingGlyph(), which lives in
main/vcl/unx/headless/svptext.cxx.  When I looked more closely at
this code to try to figure out the proper fix, I discovered that
this code is more broken than is immediately obvious.

There are two classes defined in main/vcl/inc/glyphcache.hxx that
each have a pair of similar members.  The GlyphData class contains
the private struct ExtGlyphData, which in turn contains "int meInfo"
and "void* mpData".  The ServerFont class contains the private
members "int mnExtInfo" and "void* mpExtData".

The GlyphData members are set in X11GlyphPeer::RemovingGlyph(),
X11GlyphPeer::PrepareForMultiscreen(), X11GlyphPeer::SetRenderGlyph(),
X11GlyphPeer::SetRawBitmap(), and X11GlyphPeer::SetPixmap() in
main/vcl/unx/generic/gdi/gcach_xpeer.cxx, where the meInfo value
is one of the INFO_* enum values in gcach_xpeer.cxx, and mpData can
point to various different types of objects.

The ServerFont members are set in X11GlyphPeer::RemovingFont() and
X11GlyphPeer::GetGlyphSet() in main/vcl/unx/generic/gdi/gcach_xpeer.cxx,
where the mnExtInfo value is a subset of the enum containing INFO_*
values in gcach_xpeer.cxx, and the mpExtData value is a GlyphSet.

Over on the headless side, GlyphData meInfo and mpData values are
examined in in SvpGlyphPeer::GetGlyphBmp() and
SvpGlyphPeer::RemovingGlyph(), but they are never set.  The expected
meInfo values come from the basebmp Format values in
main/basebmp/inc/basebmp/scanlineformats.hxx.  Instead,the headless
code sets the ServerFont members in SvpGlyphPeer::GetGlyphBmp()
with the mnExtInfo value coming from the basebmp Format values and
the mpExtData value being a SvpGcpHelper* fetched from mpData.  The
ServerFont members are not examined on the headless side.

The attached patch is my attempt at a fix.  It builds, but I don't know
how to do a meaningful test of headless mode.