Remove unused includes. Make it WARNS=6 friendly. Concerning bin/2442, make

a new function dup_shell() to replace ok_shell() and make it unconditionnally
strdup() its result to make the caller's code simplier. Change ok_shell() to
just return an integer value suitable for tests (it was used mainly for that
purpose). Do not use strdup() in the caller's code but rely on dup_shell()
that will do the job for us.

PR: bin/2442

usr.bin/chpass/chpass.c

@@ -53,15 +53,9 @@ static char sccsid[] = "@(#)chpass.c	8.4 (Berkeley) 4/2/94";
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
-#include <sys/stat.h>
-#include <sys/signal.h>
-#include <sys/time.h>
-#include <sys/resource.h>
 
-#include <ctype.h>
 #include <err.h>
 #include <errno.h>
-#include <fcntl.h>
 #include <pwd.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -292,7 +286,7 @@ usage(void)
 {
 
 	(void)fprintf(stderr,
-	    "Usage: chpass%s %s [user]\n",
+	    "usage: chpass%s %s [user]\n",
 #ifdef YP
 	    " [-d domain] [-h host]",
 #else

usr.bin/chpass/chpass.h

@@ -64,7 +64,8 @@ extern int master_mode;
 
 int	 atot(char *, time_t *);
 struct passwd *edit(const char *, struct passwd *);
-char    *ok_shell(char *);
+int      ok_shell(char *);
+char    *dup_shell(char *);
 int	 p_change(char *, struct passwd *, ENTRY *);
 int	 p_class(char *, struct passwd *, ENTRY *);
 int	 p_expire(char *, struct passwd *, ENTRY *);
@@ -72,7 +73,6 @@ int	 p_gecos(char *, struct passwd *, ENTRY *);
 int	 p_gid(char *, struct passwd *, ENTRY *);
 int	 p_hdir(char *, struct passwd *, ENTRY *);
 int	 p_login(char *, struct passwd *, ENTRY *);
-int	 p_login(char *, struct passwd *, ENTRY *);
 int	 p_passwd(char *, struct passwd *, ENTRY *);
 int	 p_shell(char *, struct passwd *, ENTRY *);
 int	 p_uid(char *, struct passwd *, ENTRY *);

usr.bin/chpass/field.c

@@ -56,10 +56,8 @@ __FBSDID("$FreeBSD$");
 #include <grp.h>
 #include <paths.h>
 #include <pwd.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
-#include <unistd.h>
 
 #include "chpass.h"
 
@@ -218,7 +216,6 @@ p_hdir(char *p, struct passwd *pw, ENTRY *ep __unused)
 int
 p_shell(char *p, struct passwd *pw, ENTRY *ep __unused)
 {
-	char *t;
 	struct stat sbuf;
 
 	if (!*p) {
@@ -230,15 +227,16 @@ p_shell(char *p, struct passwd *pw, ENTRY *ep __unused)
 		warnx("%s: current shell non-standard", pw->pw_shell);
 		return (-1);
 	}
-	if (!(t = ok_shell(p))) {
+	if (!ok_shell(p)) {
 		if (!master_mode) {
 			warnx("%s: non-standard shell", p);
 			return (-1);
 		}
+		pw->pw_shell = strdup(p);
 	}
 	else
-		p = t;
-	if (!(pw->pw_shell = strdup(p))) {
+		pw->pw_shell = dup_shell(p);
+	if (!pw->pw_shell) {
 		warnx("can't save entry");
 		return (-1);
 	}

usr.bin/chpass/util.c

@@ -49,7 +49,6 @@ __FBSDID("$FreeBSD$");
 #include <sys/types.h>
 
 #include <ctype.h>
-#include <pwd.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -139,18 +138,45 @@ bad:		return (1);
 	return (0);
 }
 
-char *
+int
 ok_shell(char *name)
 {
 	char *p, *sh;
 
 	setusershell();
 	while ((sh = getusershell())) {
-		if (!strcmp(name, sh))
-			return (name);
+		if (!strcmp(name, sh)) {
+			endusershell();
+			return (1);
+		}
 		/* allow just shell name, but use "real" path */
-		if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0)
-			return (sh);
+		if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0) {
+			endusershell();
+			return (1);
+		}
 	}
+	endusershell();
+	return (0);
+}
+
+char *
+dup_shell(char *name)
+{
+	char *p, *sh, *ret;
+
+	setusershell();
+	while ((sh = getusershell())) {
+		if (!strcmp(name, sh)) {
+			endusershell();
+			return (strdup(name));
+		}
+		/* allow just shell name, but use "real" path */
+		if ((p = strrchr(sh, '/')) && strcmp(name, p + 1) == 0) {
+			ret = strdup(sh);
+			endusershell();
+			return (ret);
+		}
+	}
+	endusershell();
 	return (NULL);
 }