getenv and Win32

[Guido Flohr]

Hi,

I have a problem with the MSVC compiled version of the gettext runtime 
libraries under Windows.  I change the environment variables LANG, 
LANGUAGE etc. from within a Perl module, and Perl uses the win32 
functions SetEnvironmentVariableA/SetEnvironmentVariableW for 
manipulating the environment.  See 
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/base/setenvironmentvariable.asp 
for a description.

GNU gettext, however, uses getenv() to read the environment and never 
sees these changes.  An explanation for this can be found under 
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/vccore98/html/_crt_getenv.2c_._wgetenv.asp

It says:

        getenv operates only on the data structures accessible to the
        run-time library and not on the environment segment created
        for the process by the operating system.

I am no Windows expert and can only guess which behavior is correct for 
Windows, Perl's or GNU gettext's.  For OS2 there is a special version of 
getenv() in gettext-runtime/intl/os2compat.c which has a comment "A 
version of getenv() that works from DLLs", and I suspect that a special 
getenv() function for Windows is also needed.

I have tried a quick hack in dcigettext.c:

#include <Windows.h>
static char*
win32_getenv (const char* what)
{
        char* buffer;
        /* FIXME: Maybe use GetEnvironmentVariableW() instead.  */
        unsigned long buflen = GetEnvironmentVariableA (what, NULL, 0);

        /* FIXME: Memory leak!  */
        buffer = malloc (buflen + 1);
        GetEnvironmentVariableA (what, buffer, buflen); 

        return buffer;
}       
#define getenv win32_getenv

This fixes my problem, but is of course not a real solution.

A similar problem with libintl seems to be discussed as bug #666947 of 
GNUWin32, see 
http://sourceforge.net/tracker/index.php?func=detail&aid=666947&group_id=23617&atid=379173. 
 The fix proposed there defines a new function gettext_putenv() which 
changes the "correct" environment, and should be used as a replacement 
for putenv() when changing environment variables used by gettext, not 
exactly a clean solution.

Ciao

Guido
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