Current master uncompilable on cygwin

[Enrico Forestieri]

On Fri, Jul 10, 2020 at 10:18:27PM +0200, Enrico Forestieri wrote:

> This is what I get:
> 
>   CXX      Buffer.o
> In file included from /usr/lib/gcc/x86_64-pc-cygwin/9.3.0/include/c++/unordered_set:46,
>                  from ../../src/OutputParams.h:19,
>                  from ../../src/Format.h:18,
>                  from ../../src/BufferParams.h:21,
>                  from ../../src/BiblioInfo.h:20,
>                  from ../../src/Buffer.cpp:18:
[...]
> make[4]: *** [Makefile:2213: Buffer.o] Errore 1

This is due to the recent docbook support. The failure occurs on all
platforms for which sizeof(wchar_t) == 2 (such as cygwin and mingw)
or for which HAVE_WCHAR_T is not defined (possibly FreeBSD and others).

The failure can be replicated on linux by editing config.h and changing
#define SIZEOF_WCHAR_T 4
to
#define SIZEOF_WCHAR_T 2
and recompiling.

-- 
Enrico