Remove the check_url method.

The server really should not be checking urls in this way.  If an
invalid url is given, let the error come out in the browser.  This is
the correct way to deal with this.

Author: drgrice1

lib/PGalias.pm

@@ -310,7 +310,7 @@ sub alias_for_html {
 	if ( $aux_file_id =~ /https?:/ ) { #external link_file
 		$resource_object->uri($aux_file_id);           #no unique id is needed -- external link doc
 		$resource_object->{copy_link}->{type} = 'external';
-		$resource_object->{uri}->{is_accessible} = $self->check_url($resource_object->uri());
+		$resource_object->{uri}{is_accessible} = 1;    # Assume a url is accessible.
 		return $resource_object->uri; # external links need no further processing
 	} elsif ( $aux_file_id =~ m|^/|) {
 		$file_path = $aux_file_id;
@@ -383,7 +383,6 @@ sub alias_for_html {
 # Return full url to image file  (resource_id)
 ################################################################################
 
-	# $self->debug_message("link created --alias_for_image_html: url is ".$resource_object->uri(). " check =".$self->check_url($resource_object->uri()) );
 	$resource_object->uri();  # return the uri of the resource -- in this case the URL for the file in the temp directory
 }
 
@@ -457,7 +456,7 @@ sub alias_for_tex {
 	if ( $aux_file_id =~ /https?:/ ) { # external link_file
 		$resource_object->uri($aux_file_id);           #no unique id is needed -- external link doc
 		$resource_object->{copy_link}->{type} = 'external';
-		$resource_object->{uri}->{is_accessible} = $self->check_url($resource_object->uri());
+		$resource_object->{uri}{is_accessible} = 1;    # Assume a url is accessible.
 		return $resource_object->uri; # external links need no further processing
 	} elsif ( $aux_file_id =~ m|^/|) {
 		$file_path = $aux_file_id;
@@ -585,7 +584,7 @@ sub create_link_to_tmp_file {
 			$resource_object->{path}->{is_accessible}       = (-r $linkPath);
 
 			$resource_object->uri($resource_uri);
-			$resource_object->{uri}->{is_accessible}        = $self->check_url($resource_object->uri());
+			$resource_object->{uri}{is_accessible} = 1;    # Assume a url is accessible.
 			$resource_object->{path}->{is_complete}         = 1;
 			$resource_object->{uri}->{is_complete}          = 1;
 		} else {
@@ -659,8 +658,6 @@ sub convert_file_to_png_for_tex {
 our ($macrosPath,
     # ^variable my $pwd
     $pwd,
-    # ^variable my $server_root_url
-    $server_root_url,
 	);
 
 # ^function findMacroFile
@@ -692,34 +689,6 @@ sub find_file_in_directories {
 	return; # no file found
 }
 
-
-# ^function check_url
-# ^uses %envir
-sub check_url {
-	my $self = shift;
-	my $url  = shift;
-	my $OK_CONSTANT = "200 OK";
-	return undef if $url =~ /;/;   # make sure we can't get a second command in the url
-	return undef unless $url =~/\S/;
-	#FIXME -- check for other exploits of the system call	#FIXME -- ALARM feature so that the response cannot be held up for too long.
-	#ALARM: /opt/local/bin/lwp-request -d -t 40 -mHEAD ";
-	# the -t 40 means the call times out after 40 seconds.
-	# Set this alarm in site.conf
-	#FIXME doesn't seem to work with relative addresses.
-	#FIXME  Can we get the machine name of the server?
-	 $server_root_url=$self->envir("server_root_url");
-	 $self->warning_message("check_url: server_root_url is not defined in site.conf") unless $server_root_url;
-	 unless ($url =~ /^http/ ) {
-	 	# $self->debug_message("check_url: augmenting url $url");
-	 	$url = "$server_root_url/$url";
-
-	 }
-	 my $check_url_command = WeBWorK::PG::IO::externalCommand('checkurl');
-	 my $response = `$check_url_command $url`;
-	 # $self->debug_message("check_url: response for url $url is  $response");
-	 return ($response =~ /$OK_CONSTANT/) ? 1 : 0;
-}
-
 # This is a stub for deprecated problems that call this method.  Some of the Geogebra problems that do so actually work
 # even though this method fails.
 sub findAppletCodebase {

lib/PGloadfiles.pm

@@ -91,7 +91,6 @@ sub new {
 		envir		=>	$envir,
 		macroFileList    => {},    # records macros used in compilation
 		pgFileName       => '',    # current pg file being processed
-		server_root_url  => '',    # how do we find this?
 		macrosPath       => '',
 		pwd              => '',    # current directory -- defined in initialize
 	};

lib/WeBWorK/PG.pm

@@ -272,7 +272,6 @@ sub defineProblemEnvironment ($pg_envir, $options = {}, $image_generator = undef
 		tempDirectory     => $options->{tempDirectory}     // "$pg_envir->{directories}{html_temp}/",
 		tempURL           => $options->{tempURL}           // "$pg_envir->{URLs}{tempURL}/",
 		localHelpURL      => $options->{localHelpURL}      // "$pg_envir->{URLs}{localHelpURL}/",
-		server_root_url   => $options->{server_root_url} || '',
 
 		# Other things ...
 
@@ -520,11 +519,6 @@ Public html address of the tempDirectory above.
 
 Public html address for the PG help files.
 
-=item server_root_url (string, default: '')
-
-Server root url.  This is used by check_url when verifying that static resources
-are available.  It is prepended to relative urls in this check.
-
 =item use_site_prefix (string, default: '')
 
 Site prefix prepended to image and video url's inserted into problems by the

macros/PG.pl

@@ -649,10 +649,6 @@ sub findMacroFile {
 	$PG->{PG_alias}->findMacroFile(@_);
 }
 
-sub check_url {
-	$PG->{PG_alias}->check_url(@_);
-}
-
 sub findAppletCodebase {
     my $appletName = shift;
 	my $url = eval{$PG->{PG_alias}->findAppletCodebase($appletName)};