->>> HTTP_ACCEPT_LANGUAGE=en-ie, en
->>> PATH=/usr/local/bin:/usr/ucb:/bin:/usr/bin
->>> SCRIPT_NAME=/cgi-bin/printenv.sh
->>> HTTP_USER_AGENT=Mozilla/5.0 (X11; U; Linux i686; en-ie) AppleWebKit/531.2+ (KHTML, like Gecko) Version/5.0 Safari/531.2+ Ubuntu/10.10 () Epiphany/2.30.2
->>> PWD=/home/http1/www/cgi-bin
->>> REQUEST_METHOD=GET
->>> SERVER_SOFTWARE=thttpd
->>> SERVER_NAME=zippy0
->>> SERVER_PROTOCOL=HTTP/1.1
->>> HTTP_ACCEPT_ENCODING=gzip
->>> GATEWAY_INTERFACE=CGI/1.1
->>> CGI_PATTERN=cgi-bin/*
->>> HTTP_COOKIE=ikiwiki_session_c%5E2%3Fsupport%3Dtrue=bdf13df0460966a607ba497967ea5ff4
->>> REMOTE_ADDR=10.0.0.1
->>> HTTP_ACCEPT=application/xml,application/xhtml+xml,text/html;q=0.9,text/plain;q=0.8,image/png,*/*;q=0.5
-
->>Seems to be. Using version from packaging system;
-
->>> ikiwiki-3.20110905
-
->> which I'd guess is from Apr last year. Will look for updates and post back if still
-wrong.
-
->> Cheers
-
->> -- fergus
-
->> PS: all the links generated by CGI pages omit the port; this works if i login first and then
-reset the server on the 'odd' port -- hovering over the links absolute links with the port missing.
+
+[ ... ]
+
+>>>> In apache, `HTTP_HOST` includes the port. This is not part of the CGI
+>>>> spec it seems, but perl's `CGI` module seems to rely on it,
+>>>> in `virtual_port`:
+
+>>>>> my $vh = $self->http('x_forwarded_host') || $self->http('host');
+>>>>> my $protocol = $self->protocol;
+>>>>> if ($vh) {
+>>>>> return ($vh =~ /:(\d+)$/)[0] || ($protocol eq 'https' ? 443 : 80);
+
+>>>> The `CGI` module only looks at `SERVER_PORT` when there's no
+>>>> `HTTP_HOST`. So this is either a bug in perl's CGI or thttpd.
+>>>> --[[Joey]]
+
+[ ... ]
+
+---
+
+>>>>> This is interesting. If HTTP_HOST is wrong then
+
+>>>>> 0. the client header must be wrong (i.e. not including the PORT)
+>>>>> 0. `perl`'s doing something bad[tm] (or at least lazy)
+>>>>> 0. `apache` is adding it
+>>>>> 0. `thttpd` is stripping it
+
+>>>>> Quick hack shows that `thttpd` must be stripping the port
+number from the `Host:` header. That can be fixed.
+
+>>>>> Thanks for the assist. -- fergus
+
+---
+
+Patch for `thttpd-2.25b` for posterity and completeness
+
+[[!format patch """
+
+diff --git a/libhttpd.c b/libhttpd.c
+index 73689be..039b7e3 100644
+--- a/libhttpd.c
++++ b/libhttpd.c
+@@ -2074,9 +2074,6 @@ httpd_parse_request( httpd_conn* hc )
+ cp = &buf[5];
+ cp += strspn( cp, " \t" );
+ hc->hdrhost = cp;
+- cp = strchr( hc->hdrhost, ':' );
+- if ( cp != (char*) 0 )
+- *cp = '\0';
+ if ( strchr( hc->hdrhost, '/' ) != (char*) 0 || hc->hdrhost[0] == '.' )
+ {
+ httpd_send_err( hc, 400, httpd_err400title, "", httpd_err400form, "" );
+
+"""]]
+
+-- fergus
+
+---
+
+I've gone ahead and filed a bug on CGI.pm too:
+<https://rt.cpan.org/Ticket/Display.html?id=72678> --[[Joey]]
+
+---
+
+That'll be an interesting discussion as I'd suggest that HTTP_ headers are defined in the CGI specification as client headers and thus what `thttpd` is doing is wrong (i.e. mangling the client's own representation). Whether a CGI client should trust HTTP_ header over the server is probably already settled by convention.
+
+-- fergus