w: Fix musl UT_HOSTSIZE issue

While musl has utmpx.h, their header file does not define all the
values, especially __UT_HOSTSIZE and friends. Instead it just
hard codes the sizes :/

This change will look for that definition specifically and if
not found will include utmp.h too. Checked on Alpine 3.17

musl just makes these a stub so w doesn't work anyway.

Signed-off-by: Craig Small <csmall@dropbear.xyz>

3 files changed, 15 insertions, 1 deletions

diff --git a/NEWS b/NEWS
index a5578c2..b046a40 100644
--- a/NEWS
+++ b/NEWS
@@ -8,6 +8,7 @@ procps-ng-NEXT
   * top: bad command line arguments yield EXIT_FAILURE     issue #273
   * top: avoids keystroke induced '%Cpu' distortions
   * top: includes VM (guest) tics in 'system' overhead     issue #274
+  * w: Fix musl UT_HOSTSIZE issue
 
 procps-ng-4.0.3
 ---------------
diff --git a/configure.ac b/configure.ac
index 629881a..e20a2c5 100644
--- a/configure.ac
+++ b/configure.ac
@@ -78,6 +78,16 @@ AC_TYPE_SSIZE_T
 AC_CHECK_MEMBERS([struct stat.st_rdev])
 AC_CHECK_MEMBERS([siginfo_t.si_int], [], [], [[#include <signal.h>]])
 
+dnl Needed for musl
+if test "x$ac_cv_header_utmpx_h" = xyes
+then :
+AC_CHECK_DECLS([__UT_HOSTSIZE],
+               [AC_DEFINE([HAVE_UT_HOSTSIZE_IN_UTMPX], [1],
+                          [Define if __UT_HOSTSIZE in utmpx.h])],
+               [],
+               [[#include <utmpx.h>]])
+fi
+
 dnl libtool
 LT_INIT
 
diff --git a/src/w.c b/src/w.c
index 80a867b..093cfbc 100644
--- a/src/w.c
+++ b/src/w.c
@@ -45,7 +45,10 @@
 #include <time.h>
 #include <unistd.h>
 #ifdef HAVE_UTMPX_H
-#	include <utmpx.h>
+#include <utmpx.h>
+#ifndef HAVE_UT_HOSTSIZE_IN_UTMPX
+#include <utmp.h>
+#endif
 #else
 #	include <utmp.h>
 #endif