&remote_ip: Fixed for stable headers hitting.
[MyWeb.git] / Web.pm
diff --git a/Web.pm b/Web.pm
index c0d8c3c..33cd6d9 100644 (file)
--- a/Web.pm
+++ b/Web.pm
@@ -1,8 +1,6 @@
-#! /usr/bin/perl
-# 
 # $Id$
 # Common functions for HTML/XHTML output generation
-# Copyright (C) 2003 Jan Kratochvil <project-www.jankratochvil.net@jankratochvil.net>
+# Copyright (C) 2003-2005 Jan Kratochvil <project-www.jankratochvil.net@jankratochvil.net>
 # 
 # This program is free software; you can redistribute it and/or modify
 # it under the terms of the GNU General Public License as published by
 
 package My::Web;
 require 5.6.0; # at least 'use warnings;' but we need some 5.6.0+ modules anyway
-use vars qw($VERSION);
-$VERSION=do { my @r=(q$Revision$=~/\d+/g); sprintf "%d.".("%03d"x$#r),@r; };
+our $VERSION=do { my @r=(q$Revision$=~/\d+/g); sprintf "%d.".("%03d"x$#r),@r; };
+our $CVS_ID=q$Id$;
 use strict;
 use warnings;
 
-use WebConfig; # for %WebConfig
-require CGI;   # for &escapeHTML
+use Exporter;
+sub Wrequire($);
+sub Wuse($@);
+our $W;
+our @EXPORT=qw(
+               &Wrequire &Wuse
+               &path_web &path_abs_disk
+               &uri_escaped
+               &a_href &a_href_cc
+               &vskip
+               &img &centerimg &rightimg
+               $W
+               &input_hidden_persistents
+               &escapeHTML
+               );
+our @ISA=qw(Tie::Handle Exporter);
+
+my %packages_used_hash;        # $packages_used_hash{$W->{"__PACKAGE__"}}{"_done"}=1;
+my %packages_used_array;
+
+BEGIN
+{
+       use Carp qw(cluck confess);
+       $W->{"__My::Web_init"}=1;
+
+       sub Wrequire ($)
+       {
+       my($file)=@_;
+
+#              print STDERR "Wrequire $file\n";
+               $file=~s#/#::#g;
+               $file=~s/[.]pm$//;
+               my $class=$file;
+               $file=~s#::#/#g;
+               $file.=".pm";
+               my %callers;
+               for (my $depth=0;defined caller($depth);$depth++) {
+                       $callers{caller($depth)}=1;
+                       }
+               my $selfpkg=__PACKAGE__;
+               $callers{$selfpkg}=1;
+               for my $target ($class,__PACKAGE__) {
+                       for my $caller (keys(%callers)) {
+                               next if $caller eq $target;
+                               next if $packages_used_hash{$caller}{$target}++;
+                               push @{$packages_used_array{$caller}},$target;
+                               }
+                       }
+               eval { CORE::require "$file"; } or confess $@;
+               1;      # Otherwise 'require' would already file above.
+       }
+
+       sub Wuse ($@)
+       {
+       my($file,@list)=@_;
+
+#              print STDERR "Wuse $file\n";
+               Wrequire $file;
+               local $Exporter::ExportLevel=$Exporter::ExportLevel+1;
+               $file->import(@list);
+               1;
+       }
+
+       sub import
+       {
+       my($class,@rest)=@_;
+
+               local $Exporter::ExportLevel=$Exporter::ExportLevel+1;
+               Wrequire("$class");
+               return $class->SUPER::import(@rest);
+       }
+}
+
+use WebConfig; # see also below: Wuse 'WebConfig';
+require CGI;
 require Image::Size;   # for &imgsize
 use File::Basename;    # &basename
+use Carp qw(cluck confess);
+use URI::Escape;
+require HTTP::BrowserDetect;
+require HTTP::Negotiate;
+our $have_Geo_IP; BEGIN { $have_Geo_IP=eval { require Geo::IP; 1; }; }
+# Do not: use ModPerl::Util qw(exit);
+# to prevent in mod_perl2: "exit" is not exported by the ModPerl::Util module
+# I do not know why.
+use POSIX qw(strftime);
+use Tie::Handle;
+use Apache2::Const qw(HTTP_MOVED_TEMPORARILY OK HTTP_OK);
+use URI;
+use URI::QueryParam;
+use Cwd;
+require HTTP::Date;
+require Storable;
+require Digest::MD5;
+require Data::Compare;
+use Data::Dumper;
+require Encode;
+use Apache2::Filter;
+use Apache2::Connection;
+
+
+#our $W;
+
+sub cleanup($)
+{
+my($apache_request)=@_;
 
+       $packages_used_hash{$W->{"__PACKAGE__"}}{"_done"}=1;
+       cache_finish();
+       # Sanity protection.
+       $W=undef();
+       return OK;
+}
 
-my %Args;
-               # $Args{"title"}
-               # $Args{"force_charset"}
+sub request_check(;$)
+{
+my($self)=@_;
+
+       # Use &eval to prevent: Global $r object is not available. Set:\n\tPerlOptions +GlobalRequest\nin ...
+       # CGI requires valid "r": check it beforehand here.
+       confess "Calling sensitive dynamic code from a static code" if !eval { Apache2::RequestUtil->request(); };
+       # Do not: confess "Calling sensitive dynamic code without My::Web::init" if !$W->{"__PACKAGE__"};
+       # as it is valid at least while preparing arguments to call: &project::Lib::init
+}
 
-my $cvs_id_html;
 sub init ($%)
 {
 my($class,%args)=@_;
 
-       %WebConfig=(%WebConfig,%args);  # override %WebConfig settings
+       print STDERR "$class->init ".Apache2::RequestUtil->request()->unparsed_uri()."\n";
+
+       # We need to track package dependencies, so we need to call it from &init.
+       # We cannot do it in BEGIN { } block
+       # as it would not be tracked for each of the toplevel users later.
+       Wuse 'WebConfig';
+       Wrequire 'My::Hash';
+
+       $W=My::Hash->new({
+               "__PACKAGE__"=>scalar(caller()),
+               %WebConfig,
+               %args,  # override %WebConfig settings
+               },"My::Hash::Sub","My::Hash::Push");
+
+       # {"__PACKAGE__"} is mandatory for mod_perl-2.0;
+       # $Apache2::Registry::curstash is no longer supported.
+       do { cluck "No $_" if !$W->{$_}; } for "__PACKAGE__";
+
+       # See: &escapeHTML
+       do { cluck "charset==$_, expecting ISO-8859-1" if $_ ne "ISO-8859-1"; } for CGI::charset();
+       CGI::charset("utf-8");
+
+       do { $W->{$_}=0  if !defined $W->{$_}; } for "detect_ent";
+       do { $W->{$_}=0  if !defined $W->{$_}; } for "detect_js";
+       do { $W->{$_}=1  if !defined $W->{$_}; } for "have_css";        # AFAIK it does not hurt anyone.
+       do { $W->{$_}=0  if !defined $W->{$_}; } for "css_inherit";
+       do { $W->{$_}=1  if !defined $W->{$_}; } for "footer";
+       do { $W->{$_}=1  if !defined $W->{$_}; } for "footer_delimit";
+       do { $W->{$_}=1  if !defined $W->{$_}; } for "footer_ids";
+       do { $W->{$_}=1  if !defined $W->{$_}; } for "indexme";
+       do { $W->{$_}="" if !defined $W->{$_}; } for "head";
+       do { $W->{$_}="" if !defined $W->{$_}; } for "body_attr";
+       do { $W->{$_}="en-US" if !defined $W->{$_}; } for "language";
+
+       my $footer_any=0;
+       for (qw(footer_ids)) {
+               $W->{$_}=0 if !$W->{"footer"};
+               $footer_any=1 if $W->{$_};
+               }
+       $W->{"footer"}=0 if !$footer_any;
+       $W->{"footer_delimit"}=0 if !$W->{"footer"};
+
+       $W->{"r"}=Apache2::RequestUtil->request();
+
+       $W->{"r"}->push_handlers("PerlCleanupHandler"=>\&cleanup);
+
+       $W->{"web_hostname"}||=$W->{"r"}->hostname();
+
+       tie *STDOUT,$W->{"r"};
+       select *STDOUT;
+       $|=1;
+
+       $W->{"QUERY_STRING"}=$W->{"r"}->args() || "";
+       if ($W->{"detect_ent"}) {
+                        if ($W->{"QUERY_STRING"}=~/[&]amp;have_ent/)
+                       { $W->{"have_ent"}=0; }
+               elsif ($W->{"QUERY_STRING"}=~    /[&]have_ent/)
+                       { $W->{"have_ent"}=1; }
+               else
+                       { delete $W->{"have_ent"}; }
+               if (!defined $W->{"have_ent"} && $W->{"r"}->method() eq "GET") {
+                       $W->{"head"}.='<meta http-equiv="Refresh" content="0; URL='
+                                       .escapeHTML("http://".$W->{"web_hostname"}."/".($W->{"r"}->uri()=~m#^/*(.*)$#)[0]
+                                                       ."?".($W->{"QUERY_STRING"} || "detect_ent_glue=1").'&have_ent=detect')
+                                       .'" />'."\n";
+                       }
+               }
+       $W->{"QUERY_STRING"}=~s/([&])amp;/$1/g;
+       $W->{"r"}->args($W->{"QUERY_STRING"});
+       # Workaround: &CGI::Vars behaves weird if strings passed both as POST data and in: $QUERY_STRING
+       do { $W->{"r"}->args(""); delete $ENV{"QUERY_STRING"}; } if $W->{"r"}->method() eq "POST";
+       # Do not: $W->{"r"}->args()
+       # as it parses only QUERY_STRING (not POST data).
+       $W->{"args_orig_array"}=[ CGI->new($W->{"r"})->Vars() ];
+       $W->{"args"}={ @{$W->{"args_orig_array"}} };
+       for my $name (keys(%{$W->{"args"}})) {
+               my @vals=split /\x00/,$W->{"args"}{$name};
+               next if @vals<=1;
+               $W->{"args"}{$name}=[@vals];
+               }
+
+       $W->{"headers_in"}=$W->{"r"}->headers_in();
+       Wrequire 'My::Hash::Merge';
+       $W->{"headers_in"}=My::Hash::Merge->new(
+                       $W->{"headers_in"},
+                       My::Hash::Sub->new({
+                               "_remote_ip"=>sub { return $W->{"r"}->connection()->remote_ip(); },
+                               }),
+                       );
+       $W->{"headers_in"}=My::Hash::Readonly->new($W->{"headers_in"});
+       
+       if ($W->{"r"}->method() eq "GET" || $W->{"r"}->method() eq "HEAD") {
+               for (\$W->{"http_safe"}) {
+                       # Extend the current ETag system instead if you would need it:
+                       cluck "Explicitely NOT HTTP-Safe for method \"".$W->{"r"}->method()."\"?!?"
+                                       if defined($$_) && !$$_;
+                       $$_=1 if !defined $$_;
+                       }
+               }
+       else {
+               for (\$W->{"http_safe"}) {
+                       cluck "Undefined HTTP-Safe-ty for method \"".$W->{"r"}->method()."\"!"
+                                       if !defined($$_);
+                       $$_=0 if !defined $$_;
+                       }
+               }
+       if ($W->{"http_safe"}) {
+               Wrequire 'My::Hash::RecordKeys';
+               $W->{"headers_in_RecordKeys"}=My::Hash::RecordKeys->new($W->{"headers_in"});
+               $W->{"headers_in"}=$W->{"headers_in_RecordKeys"};
+               }
+
+       $W->{"browser"}=HTTP::BrowserDetect->new($W->{"headers_in"}{"User-Agent"});
+
+       if (!defined $W->{"have_style"}) {
+               $W->{"have_style"}=(!$W->{"browser"}->netscape() || ($W->{"browser"}->major() && $W->{"browser"}->major()>4) ? 1 : 0);
+               }
 
-       undef $WebConfig{"viewcvs"} if $ENV{"SCRIPT_NAME"} && $WebConfig{"viewcvs"} eq $ENV{"SCRIPT_NAME"};
-       my @cvs_id_split=split / +/,$::CVS_ID;
-       if (@cvs_id_split==8) {
-               $cvs_id_split[2]=""
-                               ."<a href=\"".map({ s#/viewcvs/#&~checkout~/#; } $WebConfig{"viewcvs"})."?rev=".$cvs_id_split[2]."\">"
-                               .$cvs_id_split[2]."</a>";
-               $cvs_id_split[1]="<a href=\"".$WebConfig{"viewcvs"}."\">".$cvs_id_split[1]."</a>";
-               $cvs_id_split[5]="<a href=\"mailto:".$WebConfig{"admin_mail"}."\">".$cvs_id_split[5]."</a>";
+       $W->{"have_js"}=($W->{"args"}{"have_js"} ? 1 : 0);
+       if ($W->{"detect_js"} && !$W->{"have_js"}) {
+               $W->{"head"}.='<script type="text/javascript" src="'.uri_escaped(path_web('/have_js.pm')).'"></script>'."\n";
                }
-       $cvs_id_html=join " ",@cvs_id_split;
+
+       do { _args_check(%$_) if $_; } for ($W->{"args_check"});
+
+       return bless $W,$class;
 }
 
-# $args{"ListItem"}=\%...;
-sub init_project ($%)
+# Be aware other parts of code (non-My::Web) will NOT use this function!
+# Do not: Wprint $W->{"heading"},"undef"=>1;
+# as we would need to undef() it to turn it off and it would get defaulted in such case.
+# Do not: exists $W->{"heading"}
+# as we use a lot of 'for $W->{"heading"}' which instantiates it with the value: undef()
+sub Wprint($%)
 {
-my($class,%args)=@_;
+my($text,%args)=@_;
 
-       my $ListItem=$args{"ListItem"};
-       my $name=$ListItem->{"name"};
-       $name=~s#<a\s[^>]*>([^<]*)</a>#$1#g;
-       init($class,
-                       "title"=>$name,
-                       %args);
-       heading();
-       print "<h1>".$ListItem->{"name"}."</h1>\n";
-       print $ListItem->{"description"};
-       print "<hr />\n";
-       my @table=(
-               {"key"=>qr(^download\b.*),"text"=>sub ($) {
-                                               $_[0]=~s/^download//;
-                                               $_[0]=~s/^-/ /;
-                                               return "Download".$_[0];
-                                               },
-                               "format"=>sub ($) {
-                                               my $r;
-                                               if ($_[0]=~m#^[a-z]+://#) {
-                                                       $r="<a href=\"".$_[0]."\">".CGI::escapeHTML($_[0])."</a>";
-                                                       }
-                                               else {
-                                                       $r="<a href=\"".$_[0]."\">".CGI::escapeHTML(basename($_[0]))."</a>";
-                                                       my $size=(stat $_[0])[7];
-                                                       die "Cannot stat \"".$_[0]."\": $!" if !defined $size;
-                                                                if ($size>=1024*1024) { $size=int($size/(1024*1024))." MB"; }
-                                                       elsif ($size>=1024     ) { $size=int($size/(1024     ))." KB"; }
-                                                       else                     { $size=int($size            )." B"; }
-                                                       $r.=" ($size)";
-                                                       }
-                                               return $r;
-                                               }},
-               {"key"=>qr(^link\b.*),"text"=>sub ($) {
-                                               $_[0]=~s/^link-//;
-                                               return $_[0];
-                                               },
-                               "format"=>sub ($) {
-                                               return "<a href=\"".$_[0]."\">".CGI::escapeHTML($_[0])."</a>";
-                                               }},
-               {"key"=>"summary","text"=>"Summary"},
-               {"key"=>"ownership","text"=>"Ownership"},
-               {"key"=>"license","text"=>"License","format"=>sub ($) {
-                               my %known=(
-                                               "PD"=>"Public Domain",
-                                               "GPL"=>"<a href=\"http://www.gnu.org/licenses/gpl.html\">GNU General Public License</a>",
-                                               "LGPL"=>"<a href=\"http://www.gnu.org/licenses/lgpl.html\">GNU Lesser General Public License</a>",
-                                               );
-                               return $known{$_[0]};
-                               }},
-               {"key"=>"maintenance","text"=>"Currently maintained?","format"=>sub ($) {
-                               my %known=(
-                                               "finished"=>"Project is finished. No serious bugs known. No new features planned.",
-                                               "dead"=>"Project became dead code. Some updates may be needed. It is no longer used.",
-                                               );
-                               return $known{$_[0]};
-                               }},
-               {"key"=>"language","text"=>"Programming language","format"=>sub ($) {
-                               return "<a href=\"http://java.sun.com/\">".CGI::escapeHTML($_[0])."</a>"
-                                               if $_[0]=~/^Java\b/;
-                               return "<a href=\"http://www.php.net/\">".CGI::escapeHTML($_[0])."</a>"
-                                               if $_[0]=~/^PHP\b/;
-                               return undef();
-                               }},
-               );
-       print '<table border="0">'."\n";
+       cluck "undef Wprint" if !defined $text && !$args{"undef"};
+       delete $args{"undef"};
+       cluck join(" ","Invalid arguments:",keys(%args)) if keys(%args);
+       return if !defined $text;
+       cluck "utf-8 untested" if Encode::is_utf8($text);
+       $W->{"r"}->puts($text);
+}
 
-sub tableit_func
+sub escapeHTML($)
 {
-my($tableit,$val,$key)=@_;
+my($text)=@_;
 
-       print "<tr><td>";
-       if (!ref $tableit->{"text"}) {
-               print $tableit->{"text"};
+       # Prevent &CGI::escapeHTML breaking utf-8 strings like: \xC4\x9B eq \x{11B}
+       # Prevent case if we run under mod_perl but still just initializing:
+       request_check() if $ENV{"MOD_PERL"};
+       # Generally we are initialized from &init but we may be used without it without mod_perl
+       # and in such case check the change on all non-first invocations.
+       our $init;
+       if (!$ENV{"MOD_PERL"} && $init++) {
+               do { cluck "charset==$_" if $_ ne "utf-8"; } for CGI::charset();
                }
-       else {
-               my $textfunc=$tableit->{"text"};
-               print &$textfunc($key);
+       CGI::charset("utf-8");
+
+       return CGI::escapeHTML($text);
+}
+
+# local *FH;
+# tie *FH,ref($W),$W;
+sub TIEHANDLE($)
+{
+my($class,$W)=@_;
+
+       my $self={};
+       $self->{"W"}=$W or confess "Missing W";
+       return bless $self,$class;
+}
+
+sub WRITE
+{
+my($self,$scalar,$length,$offset)=@_;
+
+       Wprint substr($scalar,0,$length);
+}
+
+# /home/user/www/webdir
+sub dir_top_abs_disk()
+{
+       our $dir_top_abs_disk;
+       if (!$dir_top_abs_disk) {
+               my $selfpkg_relpath=__PACKAGE__;
+               $selfpkg_relpath=~s{::}{/}g;
+               $selfpkg_relpath.=".pm";
+               my $selfpkg_abspath=$INC{$selfpkg_relpath} or do {
+                       cluck "Unable to find self package $selfpkg_relpath";
+                       return;
+                       };
+               $selfpkg_abspath=~s{/*\Q$selfpkg_relpath\E$}{} or do {
+                       cluck "Unable to strip myself \"$selfpkg_relpath\" from the abspath: $selfpkg_abspath";
+                       return;
+                       };
+               cluck "INC{myself} is relative?: $selfpkg_abspath" if $selfpkg_abspath!~m{^/};
+               $dir_top_abs_disk=$selfpkg_abspath;
                }
-       print ":</td>";
-       if ($tableit->{"format"}) {
-               my $format=$tableit->{"format"};
-               my $valn=&$format($val);
-               $val=$valn if defined $valn;
+       return $dir_top_abs_disk;
+}
+
+sub unparsed_uri()
+{
+       request_check();
+       if (!$W->{"unparsed_uri"}) {
+               # Do not: $W->{"r"}
+               # as we may be called before &init from: &My::Project::init
+               my $r=Apache2::RequestUtil->request();
+               cluck "Calling ".'&unparsed_uri'." from a static code, going to fail" if !$r;
+               my $uri_string=$r->unparsed_uri() or cluck "Valid 'r' missing unparsed_uri()?";
+               my $uri=URI->new_abs($uri_string,"http://".$W->{"web_hostname"}."/");
+               $W->{"unparsed_uri"}=$uri;
                }
-       print "<td>$val</td></tr>\n";
+       return $W->{"unparsed_uri"};
 }
 
-       for my $tableit (@table) {
-               if (!ref $tableit->{"key"}) {
-                       tableit_func($tableit,$ListItem->{$tableit->{"key"}},$tableit->{"key"}) if $ListItem->{$tableit->{"key"}};
-                       }
-               else {
-                       for my $key (keys(%$ListItem)) {
-                               my $keyregex=$tableit->{"key"};
-                               next if $key!~/$keyregex/;
-                               tableit_func($tableit,$ListItem->{$key},$key);
-                               }
+sub in_to_uri_abs($)
+{
+my($in)=@_;
+
+       # Otherwise we may have been already processed and thus legally relativized.
+       # FIXME data: Currently disabled, all the data are too violating such rule.
+       if (0 && !ref $in) {
+               my $uri_check=URI->new($in);
+               $uri_check->scheme() || $in=~m{^\Q./\E} || $in=~m{^/}
+                               or cluck "Use './' or '/' prefix for all the local references: $in";
+               }
+       my $uri=URI->new_abs($in,unparsed_uri());
+       $uri=$uri->canonical();
+       return $uri;
+}
+
+# $args{"uri_as_in"}=1 to permit passing URI objects as: $in
+# $args{"abs"}=1;
+sub path_web($%)
+{
+my($in,%args)=@_;
+
+       cluck if !$args{"uri_as_in"} && ref $in;
+       my $uri=in_to_uri_abs($in);
+       if (uri_is_local($uri)) {
+               # Prefer the $uri values over "args_persistent" values.
+               $uri->query_form_hash({
+                               map({
+                                       my $key=$_;
+                                       my $val=$W->{"args"}{$key};
+                                       (!defined $val ? () : ($key=>$val));
+                                       } keys(%{$W->{"args_persistent"}})),
+                               %{$uri->query_form_hash()},
+                               });
+               }
+       return $uri->abs(unparsed_uri()) if $W->{"args"}{"Wabs"} || $args{"abs"};
+       return $uri->rel(unparsed_uri());
+}
+
+sub path_abs_disk_register($)
+{
+my($path_abs_disk)=@_;
+
+       $W->{"path_abs_disk_register"}{$path_abs_disk}=1;
+}
+
+# $args{"uri_as_in"}=1 to permit passing URI objects as: $in
+sub path_abs_disk($%)
+{
+my($in,%args)=@_;
+
+       cluck if !$args{"uri_as_in"} && ref $in;
+       my $uri=in_to_uri_abs($in);
+       cluck if !uri_is_local($uri);
+       my $path=$uri->path();
+       cluck "URI compatibility: ->path() not w/leading slash of URI \"$uri\"; path: $path" if $path!~m{^/};
+       my $r=dir_top_abs_disk().$path;
+       path_abs_disk_register $r if !defined $args{"register"} || $args{"register"};
+       return $r;
+}
+
+sub fatal (;$);
+
+sub _args_check (%)
+{
+my(%tmpl)=@_;
+
+       while (my($name,$regex)=each(%tmpl)) {
+               my $name_html="Parameter <span class=\"quote\">".escapeHTML($name)."</span>";
+               $W->{"args"}{$name}="" if !defined $W->{"args"}{$name};
+               $W->{"args"}{$name}=[ $W->{"args"}{$name} ] if !ref $W->{"args"}{$name} && ref $regex;
+               fatal "$name_html passed as multivar although singlevar expected"
+                               if ref $W->{"args"}{$name} && !ref $regex;
+               $regex=$regex->[0] if ref $regex;
+               for my $val (!ref $W->{"args"}{$name} ? $W->{"args"}{$name} : @{$W->{"args"}{$name}}) {
+                       $val="" if !defined $val;
+                       fatal "$name_html <span class=\"quote\">".escapeHTML($val)."</span>"
+                                                       ." does not match the required regex <span class=\"quote\">".escapeHTML($regex)."</span> "
+                                       if $regex ne "" && $val!~/$regex/;
                        }
                }
-       print "</table>\n";
+}
+
+sub vskip (;$)
+{
+my($height)=@_;
+
+       return '<p'.(!defined $height ? "" : ' style="height: '.$height.';"').'>&nbsp;</p>'."\n";
 }
 
 sub fatal (;$)
@@ -166,135 +465,675 @@ sub fatal (;$)
 my($msg)=@_;
 
        $msg="UNKNOWN" if !$msg;
+       cluck "FATAL: $msg";
 
-#      heading(false/*title*/,false/*indexme*/); // notitle is always safe, don't index the error message
-       print("\n<p>&nbsp;<br />&nbsp;</p><hr /><h1 class=\"error\">FATAL ERROR: $msg!</h1>\n"
+       # Do not send it unconditionally.
+       # The intial duplicated '<?xml...' crashes Gecko parser.
+       $W->{"heading_done"}=0 if $W->{"header_only"};
+       # Do not send it unconditionally.
+       # Prevents warn: Headers already sent
+       if (!$W->{"heading_done"}) {
+               $W->{"indexme"}=0;      # For the case no heading was sent yet.
+               $W->{"header_only"}=0;  # assurance for &heading
+               My::Web->heading();
+               }
+       Wprint "\n".vskip("3ex")."<hr /><h1 class=\"error\">FATAL ERROR: $msg!</h1>\n"
                        ."<p>You can report this problem's details to"
-                       ." <a href=\"mailto:".$WebConfig{"admin_mail"}."\">admin of this website</a>.</p>\n");
-#      footer();
+                       ." ".a_href("mailto:".$W->{"admin_mail"},"admin of this website").".</p>\n";
+       footer();
 }
 
-my $footer_passed;
 sub footer (;$)
 {
-my($delimit)=@_;
+       exit 1 if $W->{"footer_passed"}++;      # deadlock prevention:
 
-       $delimit=1 if !defined $delimit;
+       Wprint vskip if $W->{"footer_delimit"};
 
-       exit(1) if $footer_passed++;    # deadlock prevention:
+       do { Wprint $_ if $_; } for $W->{"footing_delimit"};
 
-       print "<p>&nbsp;</p>\n" if $delimit;
-       print "<hr />\n<p class=\"cvs-id\">$cvs_id_html</p>\n";
-       print "</body></html>\n";
-       exit(0);
-}
+       Wprint "<hr />\n" if $W->{"footer"};
+
+       my $packages_used=$packages_used_array{$W->{"__PACKAGE__"}};
 
-my $heading_done;
+       if ($W->{"footer_ids"}) {
+               Wprint '<p class="cvs-id">';
+               Wprint join("<br />\n",map({ my $package=$_;
+                       my $cvs_id=(eval('$'.$package."::CVS_ID")
+#                                      || $package     # debug
+                                       );
+                       if (!$cvs_id) {
+                               ();
+                               }
+                       else {
+                               $cvs_id='$'.$cvs_id.'$';        # Eaten by 'q' operator.
+                               my @cvs_id_split=split / +/,$cvs_id;
+                               if (@cvs_id_split==8) {
+                                       my $file=$package;
+                                       $file=~s#::#/#g;
+                                       my $ext;
+                                       my @tried;
+                                       for (qw(.pm)) {
+                                               $ext=$_;
+                                               my $path_abs_disk=path_abs_disk("/$file$ext");
+                                               push @tried,$path_abs_disk;
+                                               last if -r $path_abs_disk;
+                                               cluck "Class file $file not found; tried: ".join(" ",@tried) if !$ext;
+                                               }
+                                       $file.=$ext;
+                                       $cvs_id_split[2]=""
+                                                       .a_href((map({ my $s=$_; $s=~s#/viewcvs/#$&~checkout~/#; $s; } $W->{"viewcvs"}))[0]."$file?rev=".$cvs_id_split[2],
+                                                                       $cvs_id_split[2]);
+                                       $cvs_id_split[1]=a_href($W->{"viewcvs"}.$file,
+                                                       ($package!~/^Apache2::/ ? $package : $cvs_id_split[1]));
+                                       $cvs_id_split[5]=&{$W->{"cvs_id_author_sub"}}($cvs_id_split[5]);
+                                       }
+                               join " ",@cvs_id_split;
+                               }
+                       } @$packages_used));
+               Wprint "</p>\n";
+               }
+
+       for my $package (@$packages_used) {
+               my $cvs_id=(eval('$'.$package."::CVS_ID")
+#                              || $package     # debug
+                               );
+               Wprint '<!-- '.$package.' - $'.$cvs_id.'$ -->'."\n" if $cvs_id;
+               }
 
-my %headers;
-my %headers_lc;        # maps lc($headers_key)=>$headers_key
-sub header (%)
+       do { Wprint $_ if $_; } for $W->{"footing"};
+
+       Wprint "</body></html>\n";
+       exit 0;
+}
+
+# Existing entries are overwritten.
+sub header(%)
 {
 my(%pairs)=@_;
 
        while (my($key,$val)=each(%pairs)) {
-               do { warn "Headers already sent"; next; } if $heading_done;
-               for ($headers_lc{lc $key} || ()) {
-                       delete $headers{$_};
-                       }
-               $headers_lc{lc $key}=$key;
-               $headers{$key}=$val;
+               do { cluck "Headers already sent"; next; } if $W->{"heading_done"};
+               $W->{"r"}->headers_out()->set($key,$val);
                }
 }
 
+sub size_display ($)
+{
+my($size)=@_;
+
+          if ($size<4096)
+               {}
+       elsif ($size<1024*1024)
+               { $size=sprintf "%.1fK",$size/1024; }
+       else
+               { $size=sprintf "%.1fM",$size/1024/1024; }
+       $size.="B";
+       return $size;
+}
+
+sub uri_is_local($)
+{
+my($in)=@_;
+
+       my $uri_rel=in_to_uri_abs($in)->rel(unparsed_uri());
+       # Do not: defined $uri_rel->("userinfo"|"host"|"port")();
+       # as they fail to be called for schemes not supporting them.
+       return 0 if $uri_rel->scheme();
+       return 0 if $uri_rel->authority();
+       return 1;
+}
+
+# &path_web still may be required for &uri_escaped !
+sub uri_escaped($)
+{
+my($uri)=@_;
+
+       cluck if !ref $uri;
+       my $urient=escapeHTML($uri);
+       return $uri    if $uri eq $urient;
+       request_check();
+       return $urient if uri_is_local $uri;
+       return $uri    if defined $W->{"have_ent"} && !$W->{"have_ent"};        # non-ent client
+       return $urient if $W->{"have_ent"};     # ent client
+       # Unknown client, &escapeHTML should not be needed here:
+       return escapeHTML(path_web('/Redirect.pm?location='.uri_escape($uri->abs(unparsed_uri()))));
+}
+
+our $a_href_inhibited;
+sub a_href($;$%)
+{
+my($in,$contents,%args)=@_;
+
+       request_check();
+       do { $$_=1 if !defined $$_; } for (\$args{"size"});
+       if (!defined $contents) {
+               $contents=$in;
+               $contents=File::Basename::basename($contents) if $args{"basename"};
+               $contents=escapeHTML($contents);
+               }
+       $contents=~s#<a\b[^>]*>##gi;
+       $contents=~s#</a>##gi;
+       return $contents if $a_href_inhibited;
+
+       my $path_web=path_web $in,%args;
+       my $r="";
+       $r.='<a href="';
+       $r.=uri_escaped $path_web;
+       $r.='"';
+       do { $r.=" $_" if $_; } for ($args{"attr"});
+       $r.='>'.$contents.'</a>';
+       if ($args{"size"} && uri_is_local($in) && ($args{"size"}>=2 || $in=~/[.](?:gz|Z|rpm|zip|deb|lha)/)) {   # Downloadable?
+               my $path_abs_disk=path_abs_disk $in,%args;
+               cluck "File not readable: $path_abs_disk" if !-r $path_abs_disk;
+               $r.='&nbsp;('.size_display((stat($path_abs_disk))[7]).')';
+               }
+       return $r;
+}
+
+sub a_href_inhibit($$;@)
+{
+my($self,$sub,@sub_args)=@_;
+
+       local $a_href_inhibited=1;
+       return &{$sub}(@sub_args);
+}
+
+sub input_hidden_persistents()
+{
+       request_check();
+       return join("",map({
+               my $key=$_;
+               my $val=$W->{"args"}{$key};
+               (!defined $val ? () : '<input type="hidden"'
+                               .' name="'.escapeHTML($key).'"'
+                               .' value="'.escapeHTML($val).'"'
+                               .' />'."\n");
+               } (keys(%{$W->{"args_persistent"}}))));
+}
+
+sub http_moved($$;$)
+{
+my($self,$url,$status)=@_;
+
+       $url=path_web($url,"abs"=>1);
+       $status||=HTTP_MOVED_TEMPORARILY;
+       $W->{"r"}->status($status);
+       $W->{"r"}->headers_out()->{"Location"}=$url;
+       $W->{"header_only"}=1;
+       My::Web->heading();
+       exit;
+       die "NOTREACHED";
+}
+
+sub remote_ip ()
+{
+       # Do not: PerlModule                 Apache2::ForwardedFor
+       #         PerlPostReadRequestHandler Apache2::ForwardedFor
+       # As 'Apache2::ForwardedFor' takes the first of $ENV{"HTTP_X_FORWARDED_FOR"}
+       # while the contents is '127.0.0.1, 213.220.195.171' if client has its own proxy.
+       # We must take the last item ourselves.
+       # Be VERY sure you always retrieve all the headers unconditionally to hit: My::Hash::RecordKeys
+       my $x_forwarded_for=$W->{"headers_in"}{"X-Forwarded-For"};
+       $x_forwarded_for=~s/^.*,\s*// if $x_forwarded_for;
+       my $remote_ip=$W->{"headers_in"}{"_remote_ip"};
+       my $r;
+       $r||=$x_forwarded_for;
+       $r||=$remote_ip;
+       return $r;
+}
+
+# $url={"JP"=>"http://specific",...};
+# $url={""=>"http://default",...};
+sub a_href_cc($$;%)
+{
+my($url,$contents,%args)=@_;
+
+       my $cc;
+       $cc||=Geo::IP->new()->country_code_by_addr(remote_ip()) if $have_Geo_IP;
+       $cc||="";
+       $url=$url->{$cc};
+       return $contents if !$url;
+       return a_href $url,$contents,%args;
+}
+
+sub make ($)
+{
+my($cmd)=@_;
+
+       # FIXME: &alarm, --timeout is now infinite.
+       # FIXME: Try to remove bash(1).
+       # FIXME: Use: @PATH_FLOCK@
+       my @argv=('flock',dir_top_abs_disk(),'bash','-c',$cmd.' >&2');
+       print STDERR join(" ","SPAWN:",@argv)."\n";
+       system @argv;
+}
+
+sub make_file($$)
+{
+my($self,$file)=@_;
+
+       cluck "Pathname not absolute: $file" if $file!~m{^/};
+       return if -f $file;
+       # TODO: Somehow quickly check dependencies?
+       return make('make -s --no-print-directory'
+                                       .' -C '."'".File::Basename::dirname($file)."' '".File::Basename::basename($file)."'");
+}
+
 sub img_size ($$)
 {
 my($width,$height)=@_;
 
-       return((1 #$have_style TODO:dyn
-                       ? "style=\"border:0;width:${width}px;height:${height}px\"" : "border=\"0\"")
-                       ." width=\"$width\" height=\"$height\"");
+       cluck if !defined $width || !defined $height;
+       return ($W->{"have_style"} ? "style=\"border:0;width:${width}px;height:${height}px\"" : "border=\"0\"")
+                       ." width=\"$width\" height=\"$height\"";
+}
+
+sub negotiate_variant (%)
+{
+my(%args)=@_;
+
+       my @fields=("id","qs","content-type","encoding","charset","lang","size");
+       return [ map(($args{$_}),@fields) ];
+}
+
+# Input: $self is required!
+# Input: Put the fallback variant as the first one.
+# Returns: always only scalar!
+sub Negotiate_choose($$)
+{
+my($self,$variants)=@_;
+
+       # Limit these entries to generate proper 'Vary' header.
+       my %hash=(map(($_=>$W->{"headers_in"}{$_}),qw(
+                       Accept
+                       Accept-Charset
+                       Accept-Encoding
+                       Accept-Language
+                       )));
+       my $best=HTTP::Negotiate::choose($variants,
+                       # Do not: $W->{"r"}
+                       # to prevent: Can't locate object method "scan" via package "Apache2::RequestRec" at HTTP/Negotiate.pm line 84.
+                       # Do not: $W->{"r"}->headers_in()
+                       # to prevent: Can't locate object method "scan" via package "APR::Table" at HTTP/Negotiate.pm line 84.
+                       # Do not: HTTP::Headers->new($W->{"r"}->headers_in());
+                       # to prevent empty result or even: Odd number of elements in anonymous hash
+                       HTTP::Headers->new(%hash));
+       $best||=$variants->[0][0];      # $variants->[0]{"id"}; &HTTP::Negotiate::choose failed?
+       return $best;
+}
+
+my @img_variants=(
+               { "id"=>"png","qs"=>0.9,"content-type"=>"image/png" },
+               { "id"=>"gif","qs"=>0.7,"content-type"=>"image/gif" },
+               );
+my $img_variants_re='[.](?:'.join('|',"jpeg",map(($_->{"id"}),@img_variants)).')$';
+
+# Returns: ($path_web,$path_abs_disk)
+# URI path segments support ignored here. Where it is used? (';' path segment options)
+sub _img_src($%)
+{
+my($in,%args)=@_;
+
+       cluck if !uri_is_local $in;
+       my $uri=in_to_uri_abs $in;
+       my $path_abs_disk=path_abs_disk $uri,%args,"uri_as_in"=>1,"register"=>0;
+
+       # Known image extension?
+       return path_web($uri,%args,"uri_as_in"=>1),$path_abs_disk if $uri->path()=~m#$img_variants_re#o;
+
+       my @nego_variants;
+       for my $var (@img_variants) {
+               my $path_abs_disk_variant=$path_abs_disk.".".$var->{"id"};
+               path_abs_disk_register($path_abs_disk_variant);
+               __PACKAGE__->make_file($path_abs_disk_variant);
+               push @nego_variants,negotiate_variant(
+                               %$var,
+                               "size"=>(stat $path_abs_disk_variant)[7],
+                               );
+               }
+       my $ext=__PACKAGE__->Negotiate_choose(\@nego_variants);
+
+       $uri->path($uri->path().".$ext");
+       return path_web($uri,%args,"uri_as_in"=>1),path_abs_disk($uri,%args,"uri_as_in"=>1);
+}
+
+# $args{"attr"}
+sub img ($$%)
+{
+my($in,$alt,%args)=@_;
+
+       request_check();
+       my($path_web,$path_abs_disk)=_img_src($in,%args);
+       my($width,$height)=Image::Size::imgsize($path_abs_disk);
+       $alt=~s/<[^>]*>//g;
+       $alt=escapeHTML($alt);
+       my $content="<img src=\"".uri_escaped($path_web)."\" alt=\"$alt\" title=\"$alt\" ".img_size($width,$height)
+                       .(!$args{"attr"} ? "" : " ".$args{"attr"})." />";
+       do { return a_href((_img_src($_))[0],$content,"uri_as_in"=>1) if $_; } for $args{"a_href_img"};
+       do { return a_href $_,$content if $_; } for $args{"a_href"};
+       return $content;
+}
+
+sub centerimg
+{
+       my $r="";
+       $r.='<table border="0" width="100%"><tr>'."\n";
+       @_=( [@_] ) if !ref $_[0];
+       for (@_) {
+               $r.="\t".'<td align="center">'.&{\&img}(@$_).'</td>'."\n";
+               }
+       $r.='</tr></table>'."\n";
+       return $r;
+}
+
+sub rightimg
+{
+my($text,@args_img)=@_;
+
+       # FIXME: Workaround bug of 'Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)':
+       #        <col width="@{[ (!$W->{"browser"}->ie() ? "1*" : "90%" ) ]}" />
+       #        <col width="@{[ (!$W->{"browser"}->ie() ? "0*" : "10%" ) ]}" />
+       # causes whole invisible projects in: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.10) Gecko/20050719 Galeon/1.3.21
+       return <<"HERE";
+<table border="0" width="100%">
+       <tr>
+               <td align="left">
+                       @{[ $text ]}
+               </td>
+               <td align="right">
+                       @{[ &{\&img}(@args_img) ]}
+               </td>
+       </tr>
+</table>
+HERE
+}
+
+sub readfile($$)
+{
+my($class,$filename)=@_;
+
+       local *F;
+       open F,$filename or cluck "Cannot open \"$filename\": $!";
+       my $F=do { local $/=undef(); <F>; };
+       close F or cluck "Cannot close \"$filename\": $!";
+       return $F;
+}
+
+sub _no_cache($)
+{
+my($self)=@_;
+
+       header("Expires"=>HTTP::Date::time2str(1000000000));    # date in the past
+       header("Last-Modified"=>HTTP::Date::time2str());        # always modified
+       header("Cache-Control"=>join(", ",
+                       "no-cache",
+                       "no-store",
+                       "must-revalidate",
+                       "max-age=0",
+                       "pre-check=0",  # MSIE
+                       "post-check=0", # MSIE
+                       ));     # HTTP/1.1
+       header("Pragma"=>"no-cache");   # HTTP/1.0
+       header("Vary"=>"*");    # content may ba based on unpredictable sources
 }
 
-sub img ($$;$)
+sub headers_in_filtered(@)
 {
-my($file,$alt,$attrs)=@_;
+my(@keys)=@_;
 
-       (my $file_det=$file)=~s/[.]mng$/.gif/;
-       my($width,$height)=Image::Size::imgsize($file_det);
-       $alt=CGI::escapeHTML($alt);
-       return("<img src=\"$file\" alt=\"$alt\" title=\"$alt\" ".img_size($width,$height)
-                       .(!defined($attrs) ? "" : " ".$attrs)." />");
+       return map(($_=>$W->{"headers_in"}{$_}),@keys);
 }
 
+our %uri_args_frozen_to_headers_in_keys;
+our %uri_args_headers_in_frozen_to_headers_out;
 
-sub heading (;$$)
+sub uri_args_headers_in_frozen_get($)
 {
-my($class,$showtitle,$indexme)=@_;
+my($headers_in_keys_arrayref)=@_;
 
-       $showtitle=1 if !defined $showtitle;
-       $indexme=1 if !defined $indexme;
+       my %uri_args_headers_in_hash=(
+               "uri_args_frozen"=>$W->{"uri_args_frozen"},
+               "headers_in"=>{ headers_in_filtered(@$headers_in_keys_arrayref) },
+               );
+       return do { local $Storable::canonical=1; Storable::freeze(\%uri_args_headers_in_hash); };
+}
+
+sub cache_output_filter($)
+{
+my($f)=@_;
+
+       while ($f->read(my $text,0x400)) {
+               cluck "utf-8 untested" if Encode::is_utf8($text);       # Possible here at all?
+               $f->print($text);
+               $W->{"digest-md5"}->add($text);
+               }
+       return OK;
+}
+
+sub cache_start()
+{
+       if (!$W->{"http_safe"}) {
+               __PACKAGE__->_no_cache();
+               return;
+               }
+
+       {
+               # &Wrequire it here even if it will not be later used; to be stable!
+               Wrequire 'My::Hash::RestrictTo';
+               my %uri_args_hash=(
+                       "uri"=>"http://".$W->{"web_hostname"}."/".$W->{"r"}->uri(),
+                       "args"=>$W->{"args_orig_array"},
+                       );
+               $W->{"uri_args_frozen"}=do { local $Storable::canonical=1; Storable::freeze(\%uri_args_hash); };
+               last if !(my $headers_in_keys_arrayref=$uri_args_frozen_to_headers_in_keys{$W->{"uri_args_frozen"}});
+
+               # Protection to be sure we are stable:
+               $W->{"headers_in"}=My::Hash::RestrictTo->new($W->{"headers_in"},@$headers_in_keys_arrayref);
+
+               $W->{"uri_args_headers_in_frozen"}=uri_args_headers_in_frozen_get($headers_in_keys_arrayref);
+               last if !(my $headers_out_hashref=$uri_args_headers_in_frozen_to_headers_out{$W->{"uri_args_headers_in_frozen"}});
+               header(%$headers_out_hashref);
+               my $status;
+               {
+                       # &meets_conditions will always deny the attempt if !2xx status().
+                       # At least ap_read_request() sets: r->status=HTTP_REQUEST_TIME_OUT;     /* Until we get a request */
+                       my $status_old=$W->{"r"}->status();
+                       $W->{"r"}->status(HTTP_OK);
+                       # Update httpd's 'r->mtime' as the header "Last-Modified" is just not enough for ap_meets_conditions():
+                       # &update_mtime() argument is really in _secs_, not in _msecs_ as the docs claim.
+                       # Be aware '*1000000' would overflow Perl integer anyway.
+                       # &set_last_modified would also override the "Last-Modified" headers_out!
+                       # &mtime may exist but somehow does not work.
+                       $W->{"r"}->update_mtime(HTTP::Date::str2time($headers_out_hashref->{"Last-Modified"}));
+                       $status=$W->{"r"}->meets_conditions();
+                       $W->{"r"}->status($status_old);
+                       }
+               last if OK==$status;
+               $W->{"r"}->status($status);
+               exit 0;
+               die "NOTREACHED";
+               }
+
+       $W->{"digest-md5"}=Digest::MD5->new();
+       $W->{"cache_active"}=1;
+       $W->{"r"}->add_output_filter(\&cache_output_filter);
+}
+
+sub cache_finish_last_modified()
+{
+       cluck "Not yet done now? W __PACKAGE__: ".$W->{"__PACKAGE__"}
+                       if !$packages_used_hash{$W->{"__PACKAGE__"}}{"_done"};
+       for my $package_orig (@{$packages_used_array{$W->{"__PACKAGE__"}}}) {
+               local $_=$package_orig.".pm";
+               s{::}{/}g;
+               path_abs_disk "/$_","register"=>1;
+               }
+       my $mtime_newest;
+       for my $path_abs_disk (keys(%{$W->{"path_abs_disk_register"}})) {
+               my $mtime=(stat $path_abs_disk)[9];
+               do { cluck "No mtime for: $path_abs_disk"; next; } if !$mtime;
+               $mtime_newest=$mtime if !$mtime_newest || $mtime_newest<$mtime;
+               }
+       cluck "No mtime_newest found for the current W __PACKAGE__: ".$W->{"__PACKAGE__"}
+                       if !$mtime_newest;
+       return HTTP::Date::time2str($mtime_newest);
+}
+
+
+sub cache_finish()
+{
+       # Do not: return if !$W->{"uri_args_frozen"};
+       # as we may have just gave 304 and 'exit 0;' without starting the caching.
+       return if !$W->{"cache_active"};
+
+       # Fill-in/check: %uri_args_frozen_to_headers_in_keys
+       my $headers_in_keys_stored_arrayref_ref=\$uri_args_frozen_to_headers_in_keys{$W->{"uri_args_frozen"}};
+       my @headers_in_keys=tied(%{$W->{"headers_in_RecordKeys"}})->accessed();
+       if (!$$headers_in_keys_stored_arrayref_ref
+                       || !Data::Compare::Compare(\@headers_in_keys,$$headers_in_keys_stored_arrayref_ref)) {
+               cluck "Non-matching generated 'headers_in_keys' per 'uri_args_frozen' key:\n"
+                                               .Dumper(\@headers_in_keys,$$headers_in_keys_stored_arrayref_ref)
+                               if $$headers_in_keys_stored_arrayref_ref;
+               # Build or possibly prevent such further warn dupes:
+               $$headers_in_keys_stored_arrayref_ref=\@headers_in_keys;
+               # Build or regenerate as obsoleted now:
+               $W->{"uri_args_headers_in_frozen"}=uri_args_headers_in_frozen_get(\@headers_in_keys);
+               }
+
+       # Prepare 'headers_out' for the future reusal:
+       my %headers_out;
+       $headers_out{"Content-MD5"}=$W->{"digest-md5"}->b64digest();
+       # In fact we could also use MD5 for ETag as if we know ETag we also know MD5.
+       # But this way we do not need to calculate MD5 and we still can provide such ETag. So.
+       # $W->{"r"}->set_etag() ?
+       $headers_out{"ETag"}='"'.Digest::MD5::md5_base64($W->{"uri_args_headers_in_frozen"}).'"';
+       # $W->{"r"}->set_content_length() ?
+       $headers_out{"Content-Length"}=$W->{"r"}->bytes_sent();
+       my %Vary=map(($_=>1),(@headers_in_keys));
+       for (keys(%Vary)) {
+               next if !/^_/;
+               $Vary{"*"}=1;
+               delete $Vary{$_};
+               }
+       %Vary=("*"=>1) if $Vary{"*"};
+       $headers_out{"Vary"}=join(", ",sort keys(%Vary));
+       # $W->{"r"}->set_last_modified() ?
+       $headers_out{"Last-Modified"}=cache_finish_last_modified();
+
+       # Fill-in/check: %uri_args_headers_in_frozen_to_headers_out
+       my $headers_out_stored_hashref_ref=\$uri_args_headers_in_frozen_to_headers_out{$W->{"uri_args_headers_in_frozen"}};
+       if (!$$headers_out_stored_hashref_ref
+                       || !Data::Compare::Compare(\%headers_out,$$headers_out_stored_hashref_ref)) {
+               cluck "Non-matching generated 'headers_out' per 'uri_args_headers_in_frozen' key:\n"
+                                               .Dumper(\%headers_out,$$headers_out_stored_hashref_ref)
+                               if $$headers_out_stored_hashref_ref;
+               # Build or possibly prevent such further warn dupes:
+               $$headers_out_stored_hashref_ref=\%headers_out;
+               }
+
+###print STDERR Dumper(\%uri_args_frozen_to_headers_in_keys,\%uri_args_headers_in_frozen_to_headers_out);
+}
+
+sub heading()
+{
+my($class)=@_;
+
+       if (!$W->{"header_only"}) {
+               header("Content-Style-Type"=>"text/css");
+               header("Content-Script-Type"=>"text/javascript");
+               # $W->{"r"}->content_languages() ?
+               do { header("Content-Language"=>$_) if $_; } for $W->{"language"};
+               }
+       # TODO: Support also: private
+       header("Cache-Control"=>"public");      # HTTP/1.1
 
        # $ENV{"CLIENT_CHARSET"} ignored (mod_czech support dropped!)
-       my $client_charset=$Args{"force_charset"} || "us-ascii";
-       header("Content-type"=>"text/html; charset=$client_charset");
-       header("Content-Style-Type"=>"text/css");
+       my $client_charset=$W->{"force_charset"} || "us-ascii";
 
-       if ($ENV{"SERVER_SOFTWARE"}) {
-               while (my($key,$val)=each(%headers)) {
-                       print "$key: $val\n";
+       # Workaround bug
+       #   https://bugzilla.mozilla.org/show_bug.cgi?id=120556
+       # of at least
+       #   Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8b) Gecko/20050217
+       my $mime;
+       # http://validator.w3.org/ does not send ANY "Accept" headers!
+       $mime||="application/xhtml+xml" if 1
+                       && !$W->{"headers_in"}{"Accept"}
+                       && ($W->{"headers_in"}{"User-Agent"}||"")=~m{^W3C_Validator/}i;
+       $mime||=$class->Negotiate_choose([
+                       # Put the fallback variant as the first one.
+                       # Rate both variants the same to prefer "text/html" for undecided clients.
+                       # At least
+                       #   Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8b) Gecko/20050217
+                       # prefers "application/xhtml+xml" over "text/html" itself:
+                       #   text/xml,application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
+                       negotiate_variant(
+                                       "id"=>"text/html",
+                                       "content-type"=>"text/html",
+                                       "qs"=>0.6,
+                                       "charset"=>$client_charset,
+                                       "lang"=>$W->{"language"},
+                                       ),
+                       negotiate_variant(
+                                       "id"=>"application/xhtml+xml",
+                                       "content-type"=>"application/xhtml+xml",
+                                       "qs"=>0.6,
+                                       "charset"=>$client_charset,
+                                       "lang"=>$W->{"language"},
+                                       ),
+                       # application/xml ?
+                       # text/xml ?
+                       ]);
+       # mod_perl doc: If you set this header via the headers_out table directly, it
+       #               will be ignored by Apache. So do not do that.
+       $W->{"r"}->content_type("$mime; charset=$client_charset");
+
+       cache_start();
+       return if $W->{"header_only"};
+       # We still can append headers before we put out some text.
+       # FIXME: It is not clean to still append them without overwriting.
+       return if $W->{"heading_done"}++;
+
+       Wprint '<?xml version="1.0" encoding="'.$client_charset.'"?>'."\n" if $mime=~m{^application/\w+[+]xml$};
+       return if $W->{"xml_header_only"};
+       Wprint '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">'."\n";
+       Wprint '<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="'.$W->{"language"}.'">'."\n";
+       my $title=$W->{"title_prefix"}.join("",map({ ': '.$_; } ($W->{"title"} || ())));
+       # Do not: cluck if $title=~/[<>]/;
+       # as it is not solved just by: &a_href_inhibit
+       # as sometimes titles use also: <i>...</i>
+       $title=~s#<[^>]*>##g;
+       Wprint "<head>";
+       Wprint "<title>$title</title>\n";
+       if ($W->{"have_css"}) {
+               # Everything can get overriden later.
+               for my $css ("/My/Web.css",map((!$_ ? () : ("ARRAY" ne ref($_) ? $_ : @$_)),$W->{"css_push"})) {
+                       Wprint <<"HERE";
+<link rel="stylesheet" type="text/css" href="@{[ uri_escaped(path_web $css) ]}" />
+HERE
                        }
-               print "\n";
-               }
-
-       return if $heading_done++;
-
-       if (1) { # || !$msie_major || $msie_major>=4) # TODO:dyn
-               print '<?xml version="1.0" encoding="'.$client_charset.'"?>'."\n";
-               }
-       print '<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.1//EN" "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd">'."\n";
-       print '<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="cs">'."\n";
-       print '<head><title>'.CGI::escapeHTML($WebConfig{"title_prefix"})
-                       .join("",map({ ': '.CGI::escapeHTML($_); } ($WebConfig{"title"} || ())))
-                       .'</title>'."\n";
-
-       if (1) { # || $have_css)        # TODO:dyn
-               print <<'HERE';
-<style type="text/css"><!--
-.cvs-id   { font-family: monospace; }
-.error    { color: red;   background-color: transparent; }
-.quote    { font-family: monospace; }
-.nowrap   { white-space: nowrap; }
-.centered { text-align: center; }
-.tab-bold { font-weight: bold; }
-.tab-head { font-weight: bold; color: yellow; background-color: transparent; }
-body {
-               background-color: black;
-               color: white;
-               }
-:link    { color: aqua;   background-color: transparent; }
-:visited { color: teal;   background-color: transparent; }
-h1,h2    { color: yellow; background-color: transparent; }
-.footer img { vertical-align: middle; }
+               if ($W->{"css_inherit"}) {
+                       Wprint <<"HERE";
+<script type="text/javascript" src="@{[ uri_escaped(path_web('/My/css_inherit.js')) ]}" />
 HERE
-
-# TODO:dyn
-#              if (isset($head_css))
-#                      print(trim($head_css)."\n");
-               print "--></style>\n";
+                       }
+               }
+       Wprint '<meta name="robots" content="'.($W->{"indexme"} ? "" : "no" ).'index,follow" />'."\n";
+       Wprint $W->{"head"};
+       for my $type (qw(prev next index contents start up)) {
+               do { Wprint '<link rel="'.$type.'" href="'.uri_escaped(path_web $_).'" />'."\n" if $_; }
+                               for ($W->{"rel_$type"});
                }
+       Wprint "</head><body";
+#      Wprint ' bgcolor="black" text="white" link="aqua" vlink="teal"'
+#                      if $W->{"browser"}->netscape() && (!$W->{"browser"}->major() || $W->{"browser"}->major()<=4);
+       Wprint $W->{"body_attr"};
+       Wprint ">\n";
 
-       print '<meta name="robots" content="'.($indexme ? "" : "no" ).'index,follow" />'."\n";
-       print $_ for ($WebConfig{"head"} || ());
-       print "</head><body";
-# TODO:dyn
-#      if (isset($mozilla_major) && $mozilla_major==4)
-#              print(" bgcolor=\"black\" text=\"white\" link=\"aqua\" vlink=\"teal\"");
-       print ">\n";
-#      if ($showtitle)
-#              print("<h1 class=\"centered\"><a href=\"/\">"
-#                              ."Energie & Peníze")
-#                              ."</a></h1>\n");
+       do { Wprint $_ if $_; } for $W->{"heading"};
 }
 
+BEGIN {
+       delete $W->{"__My::Web_init"};
+       }
+
 1;