diff --git a/ChangeLog b/ChangeLog
index 8fcc3c7e..74ccce4c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,27 @@
+2010-08-22  Nicolas François  <nicolas.francois@centraliens.net>
+
+	* libmisc/obscure.c, lib/prototypes.h (obscure): Return a bool
+	instead of an int.
+	* libmisc/obscure.c, libmisc/tz.c, src/passwd.c, lib/encrypt.c,
+	libmisc/copydir.c, lib/prototypes.h: Add splint annotations.
+	* libmisc/tz.c: Fix some const issues.
+	* libmisc/tz.c: Avoid multi-statements lines.
+	* libmisc/tz.c: Add brackets.
+	* libmisc/copydir.c: Do not check *printf/*puts return value.
+	* libmisc/copydir.c: Fail if we cannot set or reset the SELinux
+	fscreate context.
+	* libmisc/copydir.c: Use xmalloc instead of malloc.
+	* libmisc/copydir.c: Do not check lutimes return value
+	* src/vipw.c: Avoid implicit conversion of integer to boolean.
+	* src/su.c (iswheel): Return a bool instead of an int.
+	* src/passwd.c: Remove insert_crypt_passwd(). Use xstrdup instead.
+	* src/passwd.c: Return constant strings when sufficient.
+	* src/passwd.c: Do not check *printf/*puts return value.
+	* src/passwd.c: Avoid implicit conversion of character to boolean.
+	* src/passwd.c: Do not check sleep return value.
+	* src/sulogin.c: Do not check *printf/*puts return value.
+	* lib/encrypt.c: Do not check fprintf return value.
+
 2010-08-21  Nicolas François  <nicolas.francois@centraliens.net>
 
 	* src/passwd.c: Fix a const issue.
diff --git a/lib/encrypt.c b/lib/encrypt.c
index 78132ba4..9cca4f26 100644
--- a/lib/encrypt.c
+++ b/lib/encrypt.c
@@ -40,7 +40,7 @@
 #include "prototypes.h"
 #include "defines.h"
 
-char *pw_encrypt (const char *clear, const char *salt)
+/*@exposed@*/char *pw_encrypt (const char *clear, const char *salt)
 {
 	static char cipher[128];
 	char *cp;
@@ -60,7 +60,7 @@ char *pw_encrypt (const char *clear, const char *salt)
 	 * supported, and return a DES encrypted password. */
 	if ((NULL != salt) && (salt[0] == '$') && (strlen (cp) <= 13))
 	{
-		const char *method;
+		/*@observer@*/const char *method;
 		switch (salt[1])
 		{
 			case '1':
@@ -79,9 +79,9 @@ char *pw_encrypt (const char *clear, const char *salt)
 				method = &nummethod[0];
 			}
 		}
-		fprintf (stderr,
-			 _("crypt method not supported by libcrypt? (%s)\n"),
-			  method);
+		(void) fprintf (stderr,
+		                _("crypt method not supported by libcrypt? (%s)\n"),
+		                method);
 		exit (EXIT_FAILURE);
 	}
 
diff --git a/lib/prototypes.h b/lib/prototypes.h
index 0ed95ded..54356f73 100644
--- a/lib/prototypes.h
+++ b/lib/prototypes.h
@@ -127,7 +127,7 @@ extern int selinux_file_context (const char *dst_name);
 #endif
 
 /* encrypt.c */
-extern char *pw_encrypt (const char *, const char *);
+extern /*@exposed@*/char *pw_encrypt (const char *, const char *);
 
 /* entry.c */
 extern void pw_entry (const char *, struct passwd *);
@@ -250,7 +250,7 @@ extern int do_pam_passwd_non_interractive (const char *pam_service,
 
 /* obscure.c */
 #ifndef USE_PAM
-extern int obscure (const char *, const char *, const struct passwd *);
+extern bool obscure (const char *, const char *, const struct passwd *);
 #endif
 
 /* pam_pass.c */
@@ -363,7 +363,7 @@ extern void ttytype (const char *);
 
 /* tz.c */
 #ifndef USE_PAM
-extern char *tz (const char *);
+extern /*@observer@*/const char *tz (const char *);
 #endif
 
 /* ulimit.c */
diff --git a/libmisc/copydir.c b/libmisc/copydir.c
index c3d018ed..c4a561da 100644
--- a/libmisc/copydir.c
+++ b/libmisc/copydir.c
@@ -77,7 +77,7 @@ static int copy_dir (const char *src, const char *dst,
                      uid_t old_uid, uid_t new_uid,
                      gid_t old_gid, gid_t new_gid);
 #ifdef	S_IFLNK
-static char *readlink_malloc (const char *filename);
+static /*@null@*/char *readlink_malloc (const char *filename);
 static int copy_symlink (const char *src, const char *dst,
                          unused bool reset_selinux,
                          const struct stat *statp, const struct timeval mt[],
@@ -123,7 +123,7 @@ int selinux_file_context (const char *dst_name)
 {
 	static bool selinux_checked = false;
 	static bool selinux_enabled;
-	security_context_t scontext = NULL;
+	/*@null@*/security_context_t scontext = NULL;
 
 	if (!selinux_checked) {
 		selinux_enabled = is_selinux_enabled () > 0;
@@ -236,7 +236,7 @@ static /*@exposed@*/ /*@null@*/struct link_name *check_link (const char *name, c
 	lp->ln_count = sb->st_nlink;
 	len = name_len - src_len + dst_len + 1;
 	lp->ln_name = (char *) xmalloc (len);
-	snprintf (lp->ln_name, len, "%s%s", dst_orig, name + src_len);
+	(void) snprintf (lp->ln_name, len, "%s%s", dst_orig, name + src_len);
 	lp->ln_next = links;
 	links = lp;
 
@@ -342,10 +342,10 @@ int copy_tree (const char *src_root, const char *dst_root,
 				 * Build the filename for both the source and
 				 * the destination files.
 				 */
-				snprintf (src_name, src_len, "%s/%s",
-				          src_root, ent->d_name);
-				snprintf (dst_name, dst_len, "%s/%s",
-				          dst_root, ent->d_name);
+				(void) snprintf (src_name, src_len, "%s/%s",
+				                 src_root, ent->d_name);
+				(void) snprintf (dst_name, dst_len, "%s/%s",
+				                 dst_root, ent->d_name);
 
 				err = copy_entry (src_name, dst_name,
 				                  reset_selinux,
@@ -374,7 +374,9 @@ int copy_tree (const char *src_root, const char *dst_root,
 
 #ifdef WITH_SELINUX
 	/* Reset SELinux to create files with default contexts */
-	setfscreatecon (NULL);
+	if (setfscreatecon (NULL) != 0) {
+		err = -1;
+	}
 #endif				/* WITH_SELINUX */
 
 	return err;
@@ -509,7 +511,9 @@ static int copy_dir (const char *src, const char *dst,
 	 */
 
 #ifdef WITH_SELINUX
-	selinux_file_context (dst);
+	if (selinux_file_context (dst) != 0) {
+		return -1;
+	}
 #endif				/* WITH_SELINUX */
 	if (   (mkdir (dst, statp->st_mode) != 0)
 	    || (chown_if_needed (dst, statp,
@@ -545,11 +549,11 @@ static int copy_dir (const char *src, const char *dst,
  * return NULL on error.
  * The return string shall be freed by the caller.
  */
-static char *readlink_malloc (const char *filename)
+static /*@null@*/char *readlink_malloc (const char *filename)
 {
 	size_t size = 1024;
 
-	while (1) {
+	while (true) {
 		ssize_t nchars;
 		char *buffer = (char *) malloc (size);
 		if (NULL == buffer) {
@@ -563,7 +567,7 @@ static char *readlink_malloc (const char *filename)
 			return NULL;
 		}
 
-		if ( (size_t) nchars < size) { /* The buffer was large enough */
+		if ((size_t) nchars < size) { /* The buffer was large enough */
 			/* readlink does not nul-terminate */
 			buffer[nchars] = '\0';
 			return buffer;
@@ -616,16 +620,19 @@ static int copy_symlink (const char *src, const char *dst,
 	 */
 	if (strncmp (oldlink, src_orig, strlen (src_orig)) == 0) {
 		size_t len = strlen (dst_orig) + strlen (oldlink) - strlen (src_orig) + 1;
-		char *dummy = (char *) malloc (len);
-		snprintf (dummy, len, "%s%s",
-		          dst_orig,
-		          oldlink + strlen (src_orig));
+		char *dummy = (char *) xmalloc (len);
+		(void) snprintf (dummy, len, "%s%s",
+		                 dst_orig,
+		                 oldlink + strlen (src_orig));
 		free (oldlink);
 		oldlink = dummy;
 	}
 
 #ifdef WITH_SELINUX
-	selinux_file_context (dst);
+	if (selinux_file_context (dst) != 0) {
+		free (oldlink);
+		return -1;
+	}
 #endif				/* WITH_SELINUX */
 	if (   (symlink (oldlink, dst) != 0)
 	    || (lchown_if_needed (dst, statp,
@@ -648,7 +655,7 @@ static int copy_symlink (const char *src, const char *dst,
 	 *  it returns ENOSYS on many system
 	 *  - not implemented
 	 */
-	lutimes (dst, mt);
+	(void) lutimes (dst, mt);
 #endif				/* HAVE_LUTIMES */
 
 	return 0;
@@ -701,7 +708,9 @@ static int copy_special (const char *src, const char *dst,
 	int err = 0;
 
 #ifdef WITH_SELINUX
-	selinux_file_context (dst);
+	if (selinux_file_context (dst) != 0) {
+		return -1;
+	}
 #endif				/* WITH_SELINUX */
 
 	if (   (mknod (dst, statp->st_mode & ~07777, statp->st_rdev) != 0)
@@ -756,7 +765,9 @@ static int copy_file (const char *src, const char *dst,
 		return -1;
 	}
 #ifdef WITH_SELINUX
-	selinux_file_context (dst);
+	if (selinux_file_context (dst) != 0) {
+		return -1;
+	}
 #endif				/* WITH_SELINUX */
 	ofd = open (dst, O_WRONLY | O_CREAT | O_TRUNC, statp->st_mode & 07777);
 	if (   (ofd < 0)
diff --git a/libmisc/obscure.c b/libmisc/obscure.c
index f3e27548..d4759245 100644
--- a/libmisc/obscure.c
+++ b/libmisc/obscure.c
@@ -304,15 +304,15 @@ static const char *obscure_msg (const char *old, const char *new,
  *	check passwords.
  */
 
-int obscure (const char *old, const char *new, const struct passwd *pwdp)
+bool obscure (const char *old, const char *new, const struct passwd *pwdp)
 {
 	const char *msg = obscure_msg (old, new, pwdp);
 
 	if (NULL != msg) {
 		printf (_("Bad password: %s.  "), msg);
-		return 0;
+		return false;
 	}
-	return 1;
+	return true;
 }
 
 #else				/* !USE_PAM */
diff --git a/libmisc/tz.c b/libmisc/tz.c
index e7b0b016..0f727b7b 100644
--- a/libmisc/tz.c
+++ b/libmisc/tz.c
@@ -49,23 +49,28 @@
  * tz() determines the name of the local timezone by reading the
  * contents of the file named by ``fname''.
  */
-char *tz (const char *fname)
+/*@observer@*/const char *tz (const char *fname)
 {
-	FILE *fp = 0;
+	FILE *fp = NULL;
 	static char tzbuf[BUFSIZ];
 	const char *def_tz = "TZ=CST6CDT";
 
-	if ((fp = fopen (fname, "r")) == NULL ||
-	    fgets (tzbuf, (int) sizeof (tzbuf), fp) == NULL) {
-		if (!(def_tz = getdef_str ("ENV_TZ")) || def_tz[0] == '/')
+	fp = fopen (fname, "r");
+	if (   (NULL == fp)
+	    || (fgets (tzbuf, (int) sizeof (tzbuf), fp) == NULL)) {
+		def_tz = getdef_str ("ENV_TZ");
+		if ((NULL == def_tz) || ('/' == def_tz[0])) {
 			def_tz = "TZ=CST6CDT";
+		}
 
 		strcpy (tzbuf, def_tz);
-	} else
+	} else {
 		tzbuf[strlen (tzbuf) - 1] = '\0';
+	}
 
-	if (fp)
+	if (NULL != fp) {
 		(void) fclose (fp);
+	}
 
 	return tzbuf;
 }
diff --git a/src/passwd.c b/src/passwd.c
index c677f082..6c766123 100644
--- a/src/passwd.c
+++ b/src/passwd.c
@@ -131,20 +131,19 @@ static bool do_update_pwd = false;
  */
 
 /* local function prototypes */
-static void usage (int);
+static /*@noreturn@*/void usage (int);
 
 #ifndef USE_PAM
-static int reuse (const char *, const struct passwd *);
+static bool reuse (const char *, const struct passwd *);
 static int new_password (const struct passwd *);
 
 static void check_password (const struct passwd *, const struct spwd *);
-static char *insert_crypt_passwd (const char *, const char *);
 #endif				/* !USE_PAM */
-static char *date_to_str (time_t);
-static const char *pw_status (const char *);
+static /*@observer@*/const char *date_to_str (time_t);
+static /*@observer@*/const char *pw_status (const char *);
 static void print_status (const struct passwd *);
-static void fail_exit (int);
-static void oom (void);
+static /*@noreturn@*/void fail_exit (int);
+static /*@noreturn@*/void oom (void);
 static char *update_crypt_pw (char *);
 static void update_noshadow (void);
 
@@ -158,8 +157,9 @@ static int check_selinux_access (const char *changed_user,
 /*
  * usage - print command usage and exit
  */
-static void usage (int status)
+static /*@noreturn@*/void usage (int status)
 {
+	(void)
 	fputs (_("Usage: passwd [options] [LOGIN]\n"
 	         "\n"
 	         "Options:\n"
@@ -185,7 +185,7 @@ static void usage (int status)
 }
 
 #ifndef USE_PAM
-static int reuse (const char *pass, const struct passwd *pw)
+static bool reuse (const char *pass, const struct passwd *pw)
 {
 #ifdef HAVE_LIBCRACK_HIST
 	const char *reason;
@@ -200,11 +200,11 @@ static int reuse (const char *pass, const struct passwd *pw)
 	reason = FascistHistory (pass, pw->pw_uid);
 #endif				/* !HAVE_LIBCRACK_PW */
 	if (NULL != reason) {
-		printf (_("Bad password: %s.  "), reason);
-		return 1;
+		(void) printf (_("Bad password: %s.  "), reason);
+		return true;
 	}
 #endif				/* HAVE_LIBCRACK_HIST */
-	return 0;
+	return false;
 }
 
 /*
@@ -219,7 +219,7 @@ static int new_password (const struct passwd *pw)
 	char orig[200];		/* Original password */
 	char pass[200];		/* New password */
 	int i;			/* Counter for retries */
-	int warned;
+	bool warned;
 	int pass_max_len = -1;
 	const char *method;
 
@@ -232,7 +232,7 @@ static int new_password (const struct passwd *pw)
 	 * password.
 	 */
 
-	if (!amroot && crypt_passwd[0]) {
+	if (!amroot && ('\0' != crypt_passwd[0])) {
 		clear = getpass (_("Old password: "));
 		if (NULL == clear) {
 			return -1;
@@ -240,12 +240,14 @@ static int new_password (const struct passwd *pw)
 
 		cipher = pw_encrypt (clear, crypt_passwd);
 		if (strcmp (cipher, crypt_passwd) != 0) {
+			strzero (clear);
+			strzero (cipher);
 			SYSLOG ((LOG_WARN, "incorrect password for %s",
-				 pw->pw_name));
-			sleep (1);
-			fprintf (stderr,
-				 _("Incorrect password for %s.\n"),
-				 pw->pw_name);
+			         pw->pw_name));
+			(void) sleep (1);
+			(void) fprintf (stderr,
+			                _("Incorrect password for %s.\n"),
+			                pw->pw_name);
 			return -1;
 		}
 		STRFCPY (orig, clear);
@@ -280,19 +282,19 @@ static int new_password (const struct passwd *pw)
 	}
 	if (!qflg) {
 		if (pass_max_len == -1) {
-			printf (_(
+			(void) printf (_(
 "Enter the new password (minimum of %d characters)\n"
 "Please use a combination of upper and lower case letters and numbers.\n"),
 				getdef_num ("PASS_MIN_LEN", 5));
 		} else {
-			printf (_(
+			(void) printf (_(
 "Enter the new password (minimum of %d, maximum of %d characters)\n"
 "Please use a combination of upper and lower case letters and numbers.\n"),
 				getdef_num ("PASS_MIN_LEN", 5), pass_max_len);
 		}
 	}
 
-	warned = 0;
+	warned = false;
 	for (i = getdef_num ("PASS_CHANGE_TRIES", 5); i > 0; i--) {
 		cp = getpass (_("New password: "));
 		if (NULL == cp) {
@@ -300,13 +302,13 @@ static int new_password (const struct passwd *pw)
 			return -1;
 		}
 		if (warned && (strcmp (pass, cp) != 0)) {
-			warned = 0;
+			warned = false;
 		}
 		STRFCPY (pass, cp);
 		strzero (cp);
 
 		if (!amroot && (!obscure (orig, pass, pw) || reuse (pass, pw))) {
-			puts (_("Try again."));
+			(void) puts (_("Try again."));
 			continue;
 		}
 
@@ -317,8 +319,8 @@ static int new_password (const struct passwd *pw)
 		 */
 		if (amroot && !warned && getdef_bool ("PASS_ALWAYS_WARN")
 		    && (!obscure (orig, pass, pw) || reuse (pass, pw))) {
-			puts (_("\nWarning: weak password (enter it again to use it anyway)."));
-			warned++;
+			(void) puts (_("\nWarning: weak password (enter it again to use it anyway)."));
+			warned = true;
 			continue;
 		}
 		cp = getpass (_("Re-enter new password: "));
@@ -327,7 +329,7 @@ static int new_password (const struct passwd *pw)
 			return -1;
 		}
 		if (strcmp (cp, pass) != 0) {
-			fputs (_("They don't match; try again.\n"), stderr);
+			(void) fputs (_("They don't match; try again.\n"), stderr);
 		} else {
 			strzero (cp);
 			break;
@@ -393,9 +395,9 @@ static void check_password (const struct passwd *pw, const struct spwd *sp)
 	    || (exp_status > 1)
 	    || (   (sp->sp_max >= 0)
 	        && (sp->sp_min > sp->sp_max))) {
-		fprintf (stderr,
-		         _("The password for %s cannot be changed.\n"),
-		         sp->sp_namp);
+		(void) fprintf (stderr,
+		                _("The password for %s cannot be changed.\n"),
+		                sp->sp_namp);
 		SYSLOG ((LOG_WARN, "password locked for '%s'", sp->sp_namp));
 		closelog ();
 		exit (E_NOPERM);
@@ -410,42 +412,33 @@ static void check_password (const struct passwd *pw, const struct spwd *sp)
 		ok = last + (sp->sp_min > 0 ? sp->sp_min * SCALE : 0);
 
 		if (now < ok) {
-			fprintf (stderr,
-			         _("The password for %s cannot be changed yet.\n"),
-			         pw->pw_name);
+			(void) fprintf (stderr,
+			                _("The password for %s cannot be changed yet.\n"),
+			                pw->pw_name);
 			SYSLOG ((LOG_WARN, "now < minimum age for '%s'", pw->pw_name));
 			closelog ();
 			exit (E_NOPERM);
 		}
 	}
 }
-
-/*
- * insert_crypt_passwd - add an "old-style" password to authentication
- * string result now malloced to avoid overflow, just in case.  --marekm
- */
-static char *insert_crypt_passwd (const char *string, const char *passwd)
-{
-	return xstrdup (passwd);
-}
 #endif				/* !USE_PAM */
 
-static char *date_to_str (time_t t)
+static /*@observer@*/const char *date_to_str (time_t t)
 {
 	static char buf[80];
 	struct tm *tm;
 
 	tm = gmtime (&t);
 #ifdef HAVE_STRFTIME
-	strftime (buf, sizeof buf, "%m/%d/%Y", tm);
+	(void) strftime (buf, sizeof buf, "%m/%d/%Y", tm);
 #else				/* !HAVE_STRFTIME */
-	snprintf (buf, sizeof buf, "%02d/%02d/%04d",
-		  tm->tm_mon + 1, tm->tm_mday, tm->tm_year + 1900);
+	(void) snprintf (buf, sizeof buf, "%02d/%02d/%04d",
+	                 tm->tm_mon + 1, tm->tm_mday, tm->tm_year + 1900);
 #endif				/* !HAVE_STRFTIME */
 	return buf;
 }
 
-static const char *pw_status (const char *pass)
+static /*@observer@*/const char *pw_status (const char *pass)
 {
 	if (*pass == '*' || *pass == '!') {
 		return "L";
@@ -465,25 +458,26 @@ static void print_status (const struct passwd *pw)
 
 	sp = getspnam (pw->pw_name); /* local, no need for xgetspnam */
 	if (NULL != sp) {
-		printf ("%s %s %s %ld %ld %ld %ld\n",
-			pw->pw_name,
-			pw_status (sp->sp_pwdp),
-			date_to_str (sp->sp_lstchg * SCALE),
-			(sp->sp_min * SCALE) / DAY,
-			(sp->sp_max * SCALE) / DAY,
-			(sp->sp_warn * SCALE) / DAY,
-			(sp->sp_inact * SCALE) / DAY);
+		(void) printf ("%s %s %s %ld %ld %ld %ld\n",
+		               pw->pw_name,
+		               pw_status (sp->sp_pwdp),
+		               date_to_str (sp->sp_lstchg * SCALE),
+		               (sp->sp_min * SCALE) / DAY,
+		               (sp->sp_max * SCALE) / DAY,
+		               (sp->sp_warn * SCALE) / DAY,
+		               (sp->sp_inact * SCALE) / DAY);
 	} else {
-		printf ("%s %s\n", pw->pw_name, pw_status (pw->pw_passwd));
+		(void) printf ("%s %s\n",
+		               pw->pw_name, pw_status (pw->pw_passwd));
 	}
 }
 
 
-static void fail_exit (int status)
+static /*@noreturn@*/void fail_exit (int status)
 {
 	if (pw_locked) {
 		if (pw_unlock () == 0) {
-			fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, pw_dbname ());
+			(void) fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, pw_dbname ());
 			SYSLOG ((LOG_ERR, "failed to unlock %s", pw_dbname ()));
 			/* continue */
 		}
@@ -491,7 +485,7 @@ static void fail_exit (int status)
 
 	if (spw_locked) {
 		if (spw_unlock () == 0) {
-			fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, spw_dbname ());
+			(void) fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, spw_dbname ());
 			SYSLOG ((LOG_ERR, "failed to unlock %s", spw_dbname ()));
 			/* continue */
 		}
@@ -500,9 +494,9 @@ static void fail_exit (int status)
 	exit (status);
 }
 
-static void oom (void)
+static /*@noreturn@*/void oom (void)
 {
-	fprintf (stderr, _("%s: out of memory\n"), Prog);
+	(void) fprintf (stderr, _("%s: out of memory\n"), Prog);
 	fail_exit (E_FAILURE);
 }
 
@@ -510,7 +504,7 @@ static char *update_crypt_pw (char *cp)
 {
 #ifndef USE_PAM
 	if (do_update_pwd) {
-		cp = insert_crypt_passwd (cp, crypt_passwd);
+		cp = xstrdup (crypt_passwd);
 	}
 #endif				/* !USE_PAM */
 
@@ -520,10 +514,10 @@ static char *update_crypt_pw (char *cp)
 
 	if (uflg && *cp == '!') {
 		if (cp[1] == '\0') {
-			fprintf (stderr,
-			         _("%s: unlocking the password would result in a passwordless account.\n"
-			           "You should set a password with usermod -p to unlock the password of this account.\n"),
-			         Prog);
+			(void) fprintf (stderr,
+			                _("%s: unlocking the password would result in a passwordless account.\n"
+			                  "You should set a password with usermod -p to unlock the password of this account.\n"),
+			                Prog);
 			fail_exit (E_FAILURE);
 		} else {
 			cp++;
@@ -547,24 +541,24 @@ static void update_noshadow (void)
 	struct passwd *npw;
 
 	if (pw_lock () == 0) {
-		fprintf (stderr,
-		         _("%s: cannot lock %s; try again later.\n"),
-		         Prog, pw_dbname ());
+		(void) fprintf (stderr,
+		                _("%s: cannot lock %s; try again later.\n"),
+		                Prog, pw_dbname ());
 		exit (E_PWDBUSY);
 	}
 	pw_locked = true;
 	if (pw_open (O_RDWR) == 0) {
-		fprintf (stderr,
-		         _("%s: cannot open %s\n"),
-		         Prog, pw_dbname ());
+		(void) fprintf (stderr,
+		                _("%s: cannot open %s\n"),
+		                Prog, pw_dbname ());
 		SYSLOG ((LOG_WARN, "cannot open %s", pw_dbname ()));
 		fail_exit (E_MISSING);
 	}
 	pw = pw_locate (name);
 	if (NULL == pw) {
-		fprintf (stderr,
-		         _("%s: user '%s' does not exist in %s\n"),
-		         Prog, name, pw_dbname ());
+		(void) fprintf (stderr,
+		                _("%s: user '%s' does not exist in %s\n"),
+		                Prog, name, pw_dbname ());
 		fail_exit (E_NOPERM);
 	}
 	npw = __pw_dup (pw);
@@ -573,20 +567,22 @@ static void update_noshadow (void)
 	}
 	npw->pw_passwd = update_crypt_pw (npw->pw_passwd);
 	if (pw_update (npw) == 0) {
-		fprintf (stderr,
-		         _("%s: failed to prepare the new %s entry '%s'\n"),
-		         Prog, pw_dbname (), npw->pw_name);
+		(void) fprintf (stderr,
+		                _("%s: failed to prepare the new %s entry '%s'\n"),
+		                Prog, pw_dbname (), npw->pw_name);
 		fail_exit (E_FAILURE);
 	}
 	if (pw_close () == 0) {
-		fprintf (stderr,
-		         _("%s: failure while writing changes to %s\n"),
-		         Prog, pw_dbname ());
+		(void) fprintf (stderr,
+		                _("%s: failure while writing changes to %s\n"),
+		                Prog, pw_dbname ());
 		SYSLOG ((LOG_ERR, "failure while writing changes to %s", pw_dbname ()));
 		fail_exit (E_FAILURE);
 	}
 	if (pw_unlock () == 0) {
-		fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, pw_dbname ());
+		(void) fprintf (stderr,
+		                _("%s: failed to unlock %s\n"),
+		                Prog, pw_dbname ());
 		SYSLOG ((LOG_ERR, "failed to unlock %s", pw_dbname ()));
 		/* continue */
 	}
@@ -599,14 +595,16 @@ static void update_shadow (void)
 	struct spwd *nsp;
 
 	if (spw_lock () == 0) {
-		fprintf (stderr,
-		         _("%s: cannot lock %s; try again later.\n"),
-		         Prog, spw_dbname ());
+		(void) fprintf (stderr,
+		                _("%s: cannot lock %s; try again later.\n"),
+		                Prog, spw_dbname ());
 		exit (E_PWDBUSY);
 	}
 	spw_locked = true;
 	if (spw_open (O_RDWR) == 0) {
-		fprintf (stderr, _("%s: cannot open %s\n"), Prog, spw_dbname ());
+		(void) fprintf (stderr,
+		                _("%s: cannot open %s\n"),
+		                Prog, spw_dbname ());
 		SYSLOG ((LOG_WARN, "cannot open %s", spw_dbname ()));
 		fail_exit (E_FAILURE);
 	}
@@ -616,7 +614,9 @@ static void update_shadow (void)
 		(void) spw_close ();
 		update_noshadow ();
 		if (spw_unlock () == 0) {
-			fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, spw_dbname ());
+			(void) fprintf (stderr,
+			                _("%s: failed to unlock %s\n"),
+			                Prog, spw_dbname ());
 			SYSLOG ((LOG_ERR, "failed to unlock %s", spw_dbname ()));
 			/* continue */
 		}
@@ -661,20 +661,22 @@ static void update_shadow (void)
 	}
 
 	if (spw_update (nsp) == 0) {
-		fprintf (stderr,
-		         _("%s: failed to prepare the new %s entry '%s'\n"),
-		         Prog, spw_dbname (), nsp->sp_namp);
+		(void) fprintf (stderr,
+		                _("%s: failed to prepare the new %s entry '%s'\n"),
+		                Prog, spw_dbname (), nsp->sp_namp);
 		fail_exit (E_FAILURE);
 	}
 	if (spw_close () == 0) {
-		fprintf (stderr,
-		         _("%s: failure while writing changes to %s\n"),
-		         Prog, spw_dbname ());
+		(void) fprintf (stderr,
+		                _("%s: failure while writing changes to %s\n"),
+		                Prog, spw_dbname ());
 		SYSLOG ((LOG_ERR, "failure while writing changes to %s", spw_dbname ()));
 		fail_exit (E_FAILURE);
 	}
 	if (spw_unlock () == 0) {
-		fprintf (stderr, _("%s: failed to unlock %s\n"), Prog, spw_dbname ());
+		(void) fprintf (stderr,
+		                _("%s: failed to unlock %s\n"),
+		                Prog, spw_dbname ());
 		SYSLOG ((LOG_ERR, "failed to unlock %s", spw_dbname ()));
 		/* continue */
 	}
@@ -880,9 +882,9 @@ int main (int argc, char **argv)
 			case 'w':
 				if (   (getlong (optarg, &warn) == 0)
 				    || (warn < -1)) {
-					fprintf (stderr,
-					         _("%s: invalid numeric argument '%s'\n"),
-					         Prog, optarg);
+					(void) fprintf (stderr,
+					                _("%s: invalid numeric argument '%s'\n"),
+					                Prog, optarg);
 					usage (E_BAD_ARG);
 				}
 				wflg = true;
@@ -891,9 +893,9 @@ int main (int argc, char **argv)
 			case 'x':
 				if (   (getlong (optarg, &age_max) == 0)
 				    || (age_max < -1)) {
-					fprintf (stderr,
-					         _("%s: invalid numeric argument '%s'\n"),
-					         Prog, optarg);
+					(void) fprintf (stderr,
+					                _("%s: invalid numeric argument '%s'\n"),
+					                Prog, optarg);
 					usage (E_BAD_ARG);
 				}
 				xflg = true;
@@ -901,7 +903,7 @@ int main (int argc, char **argv)
 				break;
 			case 'h':
 				usage (E_SUCCESS);
-				break;
+				/*@notreached@*/break;
 			default:
 				usage (E_BAD_ARG);
 			}
@@ -915,8 +917,9 @@ int main (int argc, char **argv)
 	 */
 	pw = get_my_pwent ();
 	if (NULL == pw) {
-		fprintf (stderr,
-		         _("%s: Cannot determine your user name.\n"), Prog);
+		(void) fprintf (stderr,
+		                _("%s: Cannot determine your user name.\n"),
+		                Prog);
 		SYSLOG ((LOG_WARN, "Cannot determine the user name of the caller (UID %lu)",
 		         (unsigned long) getuid ()));
 		exit (E_NOPERM);
@@ -944,7 +947,9 @@ int main (int argc, char **argv)
 			usage (E_USAGE);
 		}
 		if (!amroot) {
-			fprintf (stderr, _("%s: Permission denied.\n"), Prog);
+			(void) fprintf (stderr,
+			                _("%s: Permission denied.\n"),
+			                Prog);
 			exit (E_NOPERM);
 		}
 		setpwent ();
@@ -984,13 +989,15 @@ int main (int argc, char **argv)
 	}
 
 	if (anyflag && !amroot) {
-		fprintf (stderr, _("%s: Permission denied.\n"), Prog);
+		(void) fprintf (stderr, _("%s: Permission denied.\n"), Prog);
 		exit (E_NOPERM);
 	}
 
 	pw = xgetpwnam (name);
 	if (NULL == pw) {
-		fprintf (stderr, _("%s: user '%s' does not exist\n"), Prog, name);
+		(void) fprintf (stderr,
+		                _("%s: user '%s' does not exist\n"),
+		                Prog, name);
 		exit (E_NOPERM);
 	}
 #ifdef WITH_SELINUX
@@ -1001,14 +1008,14 @@ int main (int argc, char **argv)
 		security_context_t user_context = NULL;
 		const char *user = "Unknown user context";
 		if (getprevcon (&user_context) == 0) {
-			user = user_context;
+			user = user_context; /* FIXME: use context_user_get? */
 		}
 		SYSLOG ((LOG_ALERT,
 		         "%s is not authorized to change the password of %s",
 		         user, name));
-		fprintf(stderr,
-		        _("%s: %s is not authorized to change the password of %s\n"),
-		        Prog, user, name);
+		(void) fprintf(stderr,
+		               _("%s: %s is not authorized to change the password of %s\n"),
+		               Prog, user, name);
 		if (NULL != user_context) {
 			freecon (user_context);
 		}
@@ -1021,12 +1028,12 @@ int main (int argc, char **argv)
 	 * check if I'm root.
 	 */
 	if (!amroot && (pw->pw_uid != getuid ())) {
-		fprintf (stderr,
-		         _("%s: You may not view or modify password information for %s.\n"),
-		         Prog, name);
+		(void) fprintf (stderr,
+		                _("%s: You may not view or modify password information for %s.\n"),
+		                Prog, name);
 		SYSLOG ((LOG_WARN,
-			 "%s: can't view or modify password information for %s",
-			 Prog, name));
+		         "%s: can't view or modify password information for %s",
+		         Prog, name));
 		closelog ();
 		exit (E_NOPERM);
 	}
@@ -1062,13 +1069,13 @@ int main (int argc, char **argv)
 		 * Let the user know whose password is being changed.
 		 */
 		if (!qflg) {
-			printf (_("Changing password for %s\n"), name);
+			(void) printf (_("Changing password for %s\n"), name);
 		}
 
-		if (new_password (pw)) {
-			fprintf (stderr,
-				 _("The password for %s is unchanged.\n"),
-				 name);
+		if (new_password (pw) != 0) {
+			(void) fprintf (stderr,
+			                _("The password for %s is unchanged.\n"),
+			                name);
 			closelog ();
 			exit (E_NOPERM);
 		}
@@ -1094,7 +1101,7 @@ int main (int argc, char **argv)
 	}
 #endif				/* USE_PAM */
 	if (setuid (0) != 0) {
-		fputs (_("Cannot change ID to root.\n"), stderr);
+		(void) fputs (_("Cannot change ID to root.\n"), stderr);
 		SYSLOG ((LOG_ERR, "can't setuid(0)"));
 		closelog ();
 		exit (E_NOPERM);
@@ -1113,10 +1120,10 @@ int main (int argc, char **argv)
 	if (!qflg) {
 		if (!anyflag) {
 #ifndef USE_PAM
-			printf (_("%s: password changed.\n"), Prog);
+			(void) printf (_("%s: password changed.\n"), Prog);
 #endif				/* USE_PAM */
 		} else {
-			printf (_("%s: password expiry information changed.\n"), Prog);
+			(void) printf (_("%s: password expiry information changed.\n"), Prog);
 		}
 	}
 
diff --git a/src/su.c b/src/su.c
index a844edc8..6d8fecf9 100644
--- a/src/su.c
+++ b/src/su.c
@@ -112,7 +112,7 @@ static void execve_shell (const char *shellstr,
 static RETSIGTYPE kill_child (int unused(s));
 #else				/* !USE_PAM */
 static RETSIGTYPE die (int);
-static int iswheel (const char *);
+static bool iswheel (const char *);
 #endif				/* !USE_PAM */
 
 #ifndef USE_PAM
@@ -138,14 +138,14 @@ static RETSIGTYPE die (int killed)
 	}
 }
 
-static int iswheel (const char *username)
+static bool iswheel (const char *username)
 {
 	struct group *grp;
 
 	grp = getgrnam ("wheel"); /* !USE_PAM, no need for xgetgrnam */
 	if (   (NULL ==grp)
 	    || (NULL == grp->gr_mem)) {
-		return 0;
+		return false;
 	}
 	return is_on_list (grp->gr_mem, username);
 }
diff --git a/src/sulogin.c b/src/sulogin.c
index 22c23bd7..8f3f4549 100644
--- a/src/sulogin.c
+++ b/src/sulogin.c
@@ -126,7 +126,7 @@ static RETSIGTYPE catch_signals (unused int sig)
 		}
 	}
 	if (access (PASSWD_FILE, F_OK) == -1) {	/* must be a password file! */
-		puts (_("No password file"));
+		(void) puts (_("No password file"));
 #ifdef	USE_SYSLOG
 		SYSLOG (LOG_WARN, "No password file\n");
 		closelog ();
@@ -152,7 +152,7 @@ static RETSIGTYPE catch_signals (unused int sig)
 	if (getppid() == 1) {
 		setsid();
 		if (ioctl(0, TIOCSCTTY, 1) != 0) {
-			fputs (_("TIOCSCTTY failed"), stderr);
+			(void) fputs (_("TIOCSCTTY failed"), stderr);
 		}
 	}
 	while (NULL != *envp) {		/* add inherited environment, */
@@ -184,7 +184,7 @@ static RETSIGTYPE catch_signals (unused int sig)
 			/*
 			 * Fail secure
 			 */
-			puts (_("No password entry for 'root'"));
+			(void) puts (_("No password entry for 'root'"));
 #ifdef	USE_SYSLOG
 			SYSLOG (LOG_WARN, "No password entry for 'root'\n");
 			closelog ();
@@ -198,10 +198,10 @@ static RETSIGTYPE catch_signals (unused int sig)
 		 */
 
 		/* get a password for root */
-		cp = getpass (_
-			      ("\n"
-			       "Type control-d to proceed with normal startup,\n"
-			       "(or give root password for system maintenance):"));
+		cp = getpass (_(
+"\n"
+"Type control-d to proceed with normal startup,\n"
+"(or give root password for system maintenance):"));
 		/*
 		 * XXX - can't enter single user mode if root password is
 		 * empty.  I think this doesn't happen very often :-). But
@@ -213,7 +213,7 @@ static RETSIGTYPE catch_signals (unused int sig)
 			SYSLOG (LOG_INFO, "Normal startup\n");
 			closelog ();
 #endif
-			puts ("");
+			(void) puts ("");
 #ifdef	TELINIT
 			execl (PATH_TELINIT, "telinit", RUNLEVEL, (char *) 0);
 #endif
@@ -230,14 +230,14 @@ static RETSIGTYPE catch_signals (unused int sig)
 		SYSLOG (LOG_WARN, "Incorrect root password\n");
 #endif
 		sleep (2);
-		puts (_("Login incorrect"));
+		(void) puts (_("Login incorrect"));
 	}
 	strzero (pass);
 	(void) alarm (0);
 	(void) signal (SIGALRM, SIG_DFL);
 	environ = newenvp;	/* make new environment active */
 
-	puts (_("Entering System Maintenance Mode"));
+	(void) puts (_("Entering System Maintenance Mode"));
 #ifdef	USE_SYSLOG
 	SYSLOG (LOG_INFO, "System Maintenance Mode\n");
 #endif
diff --git a/src/vipw.c b/src/vipw.c
index 535338ee..d1dd3571 100644
--- a/src/vipw.c
+++ b/src/vipw.c
@@ -333,7 +333,7 @@ vipwedit (const char *file, int (*file_lock) (void), int (*file_unlock) (void))
 #ifdef WITH_SELINUX
 	/* unset the fscreatecon */
 	if (is_selinux_enabled ()) {
-		if (setfscreatecon (NULL)) {
+		if (setfscreatecon (NULL) != 0) {
 			vipwexit (_("setfscreatecon () failed"), errno, 1);
 		}
 	}