Fix to correctly test if hash ref is empty

(remove leaked debug code)

config-lib.pl

@@ -407,5 +407,89 @@ if (-r $module_prefs_conf) {
 	}
 }
 
+# read_config_params(url, insert-prefix)
+# Parses the URL parameters from a URL, and returns a hash ref
+sub read_config_params
+{
+my ($url, $pref) = @_;
+# Extract the part of the URL after the question mark
+my ($query_string) = $url =~ /\?(.*)$/;
+my %params;
+
+# Split the query string on '&' to get the individual key-value pairs
+for my $pair (split(/&/, $query_string)) {
+	my ($key, $value) = split /=/, $pair;
+	$value = &un_urlize($value);
+	my $param_prefix = $pref ? "_cparam-" : "";
+	$params{"$param_prefix$key"} = $value;
+	}
+return \%params;
+}
+
+# print_config_posted_params()
+# Prints hidden fields for all the parameters in the referrer URL
+sub print_config_posted_params
+{
+my $env_referer = $ENV{'HTTP_REFERER'};
+my $params_referer = &read_config_params($env_referer);
+my $params_url = &read_config_params($ENV{'REQUEST_URI'});
+my $params = { %$params_referer, %$params_url };
+my @params;
+if (%$params) {
+	foreach my $param (keys %{$params}) {
+		my $param_prefix = "_cparam-";
+		if ($param =~ /section|module|mode|section_next|nnext|nprev|xnavigation/ ||
+		    !$params->{$param} || $env_referer =~ /$param_prefix$param=/ ||
+		    $params_url =~ /$param_prefix$param=/ || &indexof($param, @params) > -1) {
+			next;
+			}
+		$param_prefix = "" if ($param =~ /^$param_prefix/);
+		push(@params, $param);
+		print &ui_hidden("$param_prefix$param", $params->{$param}), "\n";
+		}
+	}
+}
+
+# get_query_config_posted_params(url)
+# Returns the currently posted parameters from the URL
+sub get_query_config_posted_params
+{
+my ($url) = @_;
+foreach my $key (keys %in) {
+	if ($key =~ /^_cparam-/) {
+		my $value = $in{$key};
+		if ($value) {
+			my $delimiter = ($url =~ /\?/) ? "&" : '?';
+			$url .= "$delimiter$key=$value"
+			}
+		}
+	}
+return $url;
+}
+
+# get_config_posted_params(target)
+# Returns the referrer URL with all the parameters from the POST request
+sub get_config_posted_params
+{
+my ($target) = @_;
+my $param_prefix = "_cparam-";
+my $env_referer = $ENV{'HTTP_REFERER'};
+my $env_referer_prefixed = ($env_referer =~ /$param_prefix/ ? 1 : 0);
+my $params_referer = &read_config_params($env_referer, !$env_referer_prefixed);
+my %keys = (%in, %$params_referer);
+foreach my $key (keys %keys) {
+	if ($key =~ /^$param_prefix(.*)/) {
+		my $k = $1;
+		my $v = $keys{$key};
+		if ($v && $target !~ /$k=/) {
+			my $delimiter = ($target =~ /\?/) ? "&" : '?';
+			$v = &urlize($v) if ($v =~ /^\//);
+			$target .= "$delimiter$k=$v"
+			}
+		}
+	}
+return $target;
+}
+
 1;
 

config.cgi

@@ -25,6 +25,7 @@ else {
 
 print &ui_form_start("config_save.cgi", "post");
 print &ui_hidden("module", $m),"\n";
+&print_config_posted_params();
 print &ui_table_start(&text('config_header', $module_info{'desc'}),
 		      "width=100%", 2);
 &read_file("$config_directory/$m/config", \%newconfig);
@@ -51,5 +52,5 @@ if (!$func) {
 print &ui_table_end();
 print &ui_form_end([ [ "save", $text{'save'} ] ]);
 
-&ui_print_footer("/$m", $text{'index'});
+&ui_print_footer(&get_config_posted_params("/$m/"), $text{'index'});
 

config_save.cgi

@@ -56,5 +56,5 @@ if (&foreign_check("webmin")) {
 	}
 
 &webmin_log("_config_", undef, undef, \%in, $m);
-&redirect("/$m/");
+&redirect(&get_config_posted_params("/$m/"));
 

gray-theme/config.cgi

@@ -62,6 +62,7 @@ if (@sections > 1) {
 	print &ui_form_start("config.cgi");
 	print &ui_hidden("module", $m),"\n";
 	print $text{'config_section'},"\n";
+	&print_config_posted_params();
 	print &ui_select("section", $in{'section'}, \@sections,
 			 1, 0, 0, 0, "onChange='form.submit()'");
 	print &ui_submit($text{'config_change'});
@@ -76,6 +77,7 @@ if (@sections > 1) {
 print &ui_form_start("config_save.cgi", "post");
 print &ui_hidden("module", $m),"\n";
 print &ui_hidden("section", $in{'section'}),"\n";
+&print_config_posted_params();
 if ($s) {
 	# Find next section
 	$idx = &indexof($s, @sections);
@@ -122,6 +124,6 @@ if ($m eq "virtual-server") {
 	&ui_print_footer("/right.cgi", $text{'config_return'});
 	}
 else {
-	&ui_print_footer("/$m", $text{'index'});
+	&ui_print_footer(&get_config_posted_params("/$m/"), $text{'index'});
 	}
 

gray-theme/config_save.cgi

@@ -41,13 +41,14 @@ if (&foreign_require($m) &&
 	}
 
 &webmin_log("_config_", undef, undef, \%in, $m);
+my $redirect_url;
 if ($in{'save_next'}) {
-	&redirect("config.cgi?module=$in{'module'}&section=$in{'section_next'}");
+	$redirect_url = &get_query_config_posted_params("config.cgi?module=$in{'module'}&section=$in{'section_next'}");
 	}
 elsif ($m eq "virtual-server") {
-	&redirect("/right.cgi");
+	$redirect_url = "/right.cgi";
 	}
 else {
-	&redirect("/$m/");
+	$redirect_url = &get_config_posted_params("/$m/");
 	}
-
+&redirect($redirect_url);