Fix to use a new param to clear cache

Add hostname detection using `hostnamectl` command

filter/index.cgi

@@ -120,7 +120,7 @@ if (@filters || &get_global_spamassassin()) {
 		# Work out nice condition and action descriptions
 		local $cond;
 		($cond, $lastalways) = &describe_condition($f);
-		$cond = &ui_link("edit.cgi?idx=$f->{'index'}", &html_escape($cond));
+		$cond = &ui_link("edit.cgi?idx=$f->{'index'}", $cond);
 		local $action = &describe_action($f, \@folders);
 
 		# Create mover links

net/cygwin-lib.pl

@@ -371,7 +371,7 @@ return &get_system_hostname();
 sub save_hostname
 {
 &system_logged("hostname $_[0] >/dev/null 2>&1");
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 # get_domainname()

net/debian-linux-lib.pl

@@ -583,7 +583,7 @@ if (&has_command("hostnamectl")) {
 		       " >/dev/null 2>&1");
 	}
 
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 # get_domainname()

net/freebsd-lib.pl

@@ -583,7 +583,7 @@ my ($hostname) = @_;
 &system_logged("hostname ".quotemeta($hostname)." >/dev/null 2>&1");
 &save_rc_conf('hostname', $_[0]);
 &unlock_file("/etc/rc.conf");
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 sub routing_config_files

net/macos-lib.pl

@@ -396,7 +396,7 @@ my ($hostname) = @_;
 &lock_file($hostconfig);
 &set_hostconfig("HOSTNAME", $hostname);
 &unlock_file($hostconfig);
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 sub routing_config_files

net/netplan-lib.pl

@@ -437,7 +437,7 @@ if (&has_command("hostnamectl")) {
 		       " >/dev/null 2>&1");
 	}
 
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 # get_domainname()

net/nm-lib.pl

@@ -334,7 +334,7 @@ if (&has_command("hostnamectl")) {
 		       " >/dev/null 2>&1");
 	}
 
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 # get_domainname()

net/open-linux-lib.pl

@@ -131,7 +131,7 @@ local %conf;
 $conf{'HOSTNAME'} = $_[0];
 &write_file($network_config, \%conf);
 &unlock_file($network_config);
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 # get_domainname()

net/openbsd-lib.pl

@@ -417,7 +417,7 @@ my ($hostname) = @_;
 &open_lock_tempfile(MYNAME, ">/etc/myname");
 &print_tempfile(MYNAME, $hostname,"\n");
 &close_tempfile(MYNAME);
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 sub set_line {

net/redhat-linux-lib.pl

@@ -506,7 +506,7 @@ if (&has_command("hostnamectl")) {
 		       " >/dev/null 2>&1");
 	}
 
-undef(@main::get_system_hostname);	# clear cache
+&get_system_hostname(undef, undef, 2);	# clear cache
 }
 
 # get_domainname()

net/slackware-linux-9.1-ALL-lib.pl

@@ -274,7 +274,7 @@ sub save_hostname
 &open_lock_tempfile(HOST, ">/etc/HOSTNAME");
 &print_tempfile(HOST, $_[0],"\n");
 &close_tempfile(HOST);
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 sub routing_config_files

net/slackware-linux-lib.pl

@@ -236,7 +236,7 @@ sub save_hostname
 &open_lock_tempfile(HOST, ">/etc/HOSTNAME");
 &print_tempfile(HOST, $_[0],"\n");
 &close_tempfile(HOST);
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 sub routing_config_files

net/solaris-lib.pl

@@ -442,7 +442,7 @@ if (-r "/etc/nodename") {
 	&print_tempfile(NODENAME, $_[0],"\n");
 	&close_tempfile(NODENAME);
 	}
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 # get_domainname()

net/suse-linux-9.0-lib.pl

@@ -172,7 +172,7 @@ local %conf;
 &open_lock_tempfile(HOST, ">/etc/HOSTNAME");
 &print_tempfile(HOST, $_[0],"\n");
 &close_tempfile(HOST);
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 sub routing_config_files

net/suse-linux-9.2-ALL-lib.pl

@@ -258,7 +258,7 @@ local %conf;
 &open_lock_tempfile(HOST, ">/etc/HOSTNAME");
 &print_tempfile(HOST, $_[0],"\n");
 &close_tempfile(HOST);
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 sub routing_config_files

net/suse-linux-lib.pl

@@ -200,7 +200,7 @@ local $rc = &parse_rc_config();
 # run SuSEconfig, as this function is called last
 &system_logged("SuSEconfig -quick >/dev/null 2>&1");
 
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 sub routing_config_files

net/united-linux-lib.pl

@@ -136,7 +136,7 @@ local %conf;
 $conf{'HOSTNAME'} = $_[0];
 &write_env_file($network_config, \%conf);
 &unlock_file($network_config);
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 # get_domainname()

net/unixware-lib.pl

@@ -314,7 +314,7 @@ return &get_system_hostname();
 sub save_hostname
 {
 &system_logged("hostname $_[0] >/dev/null 2>&1");
-undef(@main::get_system_hostname);      # clear cache
+&get_system_hostname(undef, undef, 2);      # clear cache
 }
 
 # get_domainname()

web-lib-funcs.pl

@@ -4237,19 +4237,36 @@ my $func = "${pkg}::${sub}";
 return defined(&$func);
 }
 
-=head2 get_system_hostname([short], [skip-file])
+=head2 get_system_hostname([short], [skip-file], [nocache])
 
-Returns the hostname of this system. If the short parameter is set to 1,
-then the domain name is not prepended - otherwise, Webmin will attempt to get
-the fully qualified hostname, like foo.example.com.
+Returns the hostname of this system. If the short parameter is set to 1 then
+the domain name is not prepended - otherwise, Webmin will attempt to get the
+fully qualified hostname, like foo.example.com.
+If the nocache parameter is set to 1 it will flush the cache and re-read the
+hostname from the system. If the nocache parameter is set to 2 it will flush
+the cache and exit.
 
 =cut
 sub get_system_hostname
 {
-my $m = int($_[0]);
-my $skipfile = $_[1];
-if (!$main::get_system_hostname[$m]) {
+my ($m , $skipfile, $nocache) = @_;
+$m = int($m);
+state @system_hostname;
+undef(@system_hostname) if ($nocache);
+return if ($nocache == 2);
+if (!$system_hostname[$m]) {
 	if ($gconfig{'os_type'} ne 'windows') {
+		# Try hostnamectl command on Linux
+		if (&has_command("hostnamectl")) {
+			my $hostname =
+				&backquote_command("hostnamectl --static");
+			chop($hostname);
+			if ($? == 0 && $hostname =~ /\./) {
+				$hostname =~ s/\..*$// if ($m);
+				$system_hostname[$m] = $hostname;
+				return $hostname;
+				}
+			}
 		# Try some common Linux hostname files first
 		my $fromfile;
 		if ($skipfile) {
@@ -4330,24 +4347,24 @@ if (!$main::get_system_hostname[$m]) {
 			if ($m) {
 				$fromfile =~ s/\..*$//;
 				}
-			$main::get_system_hostname[$m] = $fromfile;
+			$system_hostname[$m] = $fromfile;
 			return $fromfile;
 			}
 
 		# Can use hostname command on Unix
 		&execute_command("hostname", undef,
-				 \$main::get_system_hostname[$m], undef, 0, 1);
-		chop($main::get_system_hostname[$m]);
+				 \$system_hostname[$m], undef, 0, 1);
+		chop($system_hostname[$m]);
 		if ($?) {
 			eval "use Sys::Hostname";
 			if (!$@) {
-				$main::get_system_hostname[$m] = eval "hostname()";
+				$system_hostname[$m] = eval "hostname()";
 				}
-			if ($@ || !$main::get_system_hostname[$m]) {
-				$main::get_system_hostname[$m] = "UNKNOWN";
+			if ($@ || !$system_hostname[$m]) {
+				$system_hostname[$m] = "UNKNOWN";
 				}
 			}
-		elsif ($main::get_system_hostname[$m] !~ /\./ &&
+		elsif ($system_hostname[$m] !~ /\./ &&
 		       $gconfig{'os_type'} =~ /linux$/ &&
 		       !$gconfig{'no_hostname_f'} && !$_[0]) {
 			# Try with -f flag to get fully qualified name
@@ -4356,7 +4373,7 @@ if (!$main::get_system_hostname[$m]) {
 						  undef, 0, 1);
 			chop($flag);
 			if (!$ex && $flag ne "") {
-				$main::get_system_hostname[$m] = $flag;
+				$system_hostname[$m] = $flag;
 				}
 			}
 		}
@@ -4368,14 +4385,14 @@ if (!$main::get_system_hostname[$m]) {
 		# Fall back to net name command
 		my $out = `net name 2>&1`;
 		if ($out =~ /\-+\r?\n(\S+)/) {
-			$main::get_system_hostname[$m] = $1;
+			$system_hostname[$m] = $1;
 			}
 		else {
-			$main::get_system_hostname[$m] = "windows";
+			$system_hostname[$m] = "windows";
 			}
 		}
 	}
-return $main::get_system_hostname[$m];
+return $system_hostname[$m];
 }
 
 =head2 get_webmin_version