Fix compiling with musl's utmp stubs

This patch fixes compiling busybox with FEATURE_UTMP and _WTMP enabled.
musl, while not really support utmp/wtmp, provides stub functions, as well
as variables such as _PATH_UTMP, so that programs using utmp or wtmp can
still compile fine.

My reasoning for this patch is that on Exherbo, I'm currently trying to get
us to be able to use the same busybox config file for both glibc and musl
systems, using utmp/wtmp on systems that support it, and using the stubs
on musl without needing two different configs.

As of latest musl git, it provides all utmp functions needed; 1.1.12 doesn't,
but I sent a patch to Rich to add the utmp{,x}name functions expected to
exist, which was merged into musl upstream.

Signed-off-by: Kylie McClain <somasissounds@gmail.com>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>

4 files changed, 5 insertions, 3 deletions

diff --git a/include/libbb.h b/include/libbb.h
index 82484f911..d05ac2976 100644
--- a/include/libbb.h
+++ b/include/libbb.h
@@ -20,6 +20,7 @@
 #include <netdb.h>
 #include <setjmp.h>
 #include <signal.h>
+#include <paths.h>
 #if defined __UCLIBC__ /* TODO: and glibc? */
 /* use inlined versions of these: */
 # define sigfillset(s)    __sigfillset(s)
@@ -106,7 +107,11 @@
 #  define updwtmpx updwtmp
 #  define _PATH_UTMPX _PATH_UTMP
 # else
+#  include <utmp.h>
 #  include <utmpx.h>
+#  if defined _PATH_UTMP && !defined _PATH_UTMPX
+#   define _PATH_UTMPX _PATH_UTMP
+#  endif
 # endif
 #endif
 #if ENABLE_LOCALE_SUPPORT
diff --git a/init/init.c b/init/init.c
index 80c5d0f74..2040a59e8 100644
--- a/init/init.c
+++ b/init/init.c
@@ -112,7 +112,6 @@
 
 #include "libbb.h"
 #include <syslog.h>
-#include <paths.h>
 #include <sys/resource.h>
 #ifdef __linux__
 # include <linux/vt.h>
diff --git a/shell/ash.c b/shell/ash.c
index daec975c5..b5a2d961d 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -37,7 +37,6 @@
 
 #define JOBS ENABLE_ASH_JOB_CONTROL
 
-#include <paths.h>
 #include <setjmp.h>
 #include <fnmatch.h>
 #include <sys/times.h>
diff --git a/sysklogd/klogd.c b/sysklogd/klogd.c
index ca8b848bd..03d65b37f 100644
--- a/sysklogd/klogd.c
+++ b/sysklogd/klogd.c
@@ -98,7 +98,6 @@ static void klogd_close(void)
 
 #else
 
-# include <paths.h>
 # ifndef _PATH_KLOG
 #  ifdef __GNU__
 #   define _PATH_KLOG "/dev/klog"