Fail if password change prompt is checked but won't work

acl/lang/en

@@ -125,6 +125,7 @@ save_eminsize=Missing or non-numeric minimum password length
 save_edays=No days to allow selected
 save_ehours=Missing or invalid times to allow
 save_ehours2=Start time to allow must be before end
+save_etemp=The option to force a password change at next login cannot be used unless <a href='$1'>prompting users to enter new passwords</a> is enabled
 
 delete_err=Failed to delete user
 delete_eself=You cannot delete yourself

acl/save_user.cgi

@@ -314,6 +314,11 @@ elsif ($in{'lock'} && $user{'pass'} !~ /^\!/ && $in{'pass_def'} <= 1) {
 
 # Check for force change
 $user{'temppass'} = $in{'temp'};
+if ($in{'temp'}) {
+	&get_miniserv_config(\%miniserv);
+	$miniserv{'passwd_mode'} == 2 ||
+		&error(&text('save_etemp', '../webmin/edit_session.cgi'));
+	}
 
 if ($in{'old'}) {
 	# update user and all ACLs