C89 bug when compiling on MinGW (not subscribed)

["carlo.bramix@libero.it" <ca...@libero.it>]

Hello,
I compiled successfully SVN on MINGW+MSYS but I got this error during the 
process:

/bin/sh /home/Carlo/subversion-1.8.3/libtool --tag=CC --silent --mode=compile 
gcc -std=c89  -DWIN32 -D__MSVCRT__ -D_LARGEFILE64_SOURCE   -g -O2  -g -O2  -I.
/subversion/include -I./subversion -I/mingw/include/apr-1   -
I/mingw/include/apr-1 -o subversion/libsvn_subr/win32_xlate.lo -c 
subversion/libsvn_subr/win32_xlate.c
subversion/libsvn_subr/win32_xlate.c:81: error: redefinition of typedef 
'win32_xlate_t'
subversion/libsvn_subr/win32_xlate.h:30: error: previous declaration of 
'win32_xlate_t' was here
subversion/libsvn_subr/win32_xlate.c: In function 
`svn_subr__win32_xlate_to_stringbuf':
subversion/libsvn_subr/win32_xlate.c:205: warning: assignment makes pointer 
from integer without a cast
make: *** [subversion/libsvn_subr/win32_xlate.lo] Error 1

Actually, the subversion/libsvn_subr/win32_xlate.h declares some functions 
with an opaque structure called win32_xlate_t, but since the build process is 
feeding the option "-std=c89", it fails because it seems that the opaque and 
complete structures are not supported in that dialect at the same time.
Probably, this defect has been never seen before because perhaps until now SVN 
for native Windows has been never compiled with GCC (cygwin is POSIX, not 
WIN32, so it does not count).
The missing conformance to C89 can be resolved by either declaring the 
complete structure inside subversion/libsvn_subr/win32_xlate.h, or by making 
that parameter in those functions really opaque, with a pointer to void that it 
will be eventually casted later to win32_xlate_t.

I have prepared two patches for this bug: each patch implements one of the two 
solutions described above so you can use the best for you (anyways, they are 
both easy fixes).

Sincerely,

Carlo Bramini.