Bugzilla Bug 223117

sys-auth/pam_usb-0.4.2 build fails with this log:
gcc -c -O2 -fomit-frame-pointer -pipe -mfpmath=sse -march=core2 -Wall -fPIC
`pkg-config --cflags libxml-2.0` `pkg-config --cflags hal-storage` src/pam.c -o
src/pam.o
src/pam.c: In function ‘pam_sm_authenticate’:
src/pam.c:48: error: ‘NULL’ undeclared (first use in this function)
src/pam.c:48: error: (Each undeclared identifier is reported only once
src/pam.c:48: error: for each function it appears in.)
src/pam.c:55: warning: implicit declaration of function ‘strcmp’

For reference, 0.4.1 builds just fine.

The 0.4.2 version pam.c file includes following headers:

#include <security/pam_modules.h>
#include <security/pam_appl.h>
(and few local files)

In any of them there is no declaration of NULL or including of any glibc
headers. Whereas in 0.4.1 pam.c we have:

#include <security/pam_modules.h>
#include <security/_pam_macros.h>

The <security/_pam_macros.h> header makes the difference. 
I don't know the pam_usb source and I think that including the header may be
not a good soulution, but we always patch the pam.c source file with e.g.
#include <stdio.h> or suchlike.

This is my fault. But funnily enough here it builds, probably something creeps
in here. Will fix in a second.

Okay should be fine now, sorry for the mess.