Re: [PATCH v2 2/2] gitweb: remove invalid http-equiv="content-type"

From: Jason Yundt <jason@jasonyundt.email>
To: "brian m. carlson" <sandals@crustytoothpaste.net>,
	"Ævar Arnfjörð Bjarmason" <avarab@gmail.com>
Cc: git@vger.kernel.org, Jeff King <peff@peff.net>
Subject: Re: [PATCH v2 2/2] gitweb: remove invalid http-equiv="content-type"
Date: Tue, 08 Mar 2022 09:54:21 -0500	[thread overview]
Message-ID: <4175455.ejJDZkT8p0@jason-desktop-linux> (raw)
In-Reply-To: <220308.86cziwy595.gmgdl@evledraar.gmail.com>

On Tuesday, March 8, 2022 7:44:35 AM EST Ævar Arnfjörð Bjarmason wrote:
> Maybe I still don't understand this, but the commit message seems to me
> be conflating whether we send the *right* http-equiv with whether we
> send it at all,

The intent behind the commit message is to say that <meta
http-equiv="content-type" …> is never correct in XHTML.

> i.e. if the problem is that XML documents shouldn't be
> text/html isn't this correct?:
> 	
> 	diff --git a/gitweb/gitweb.perl b/gitweb/gitweb.perl
> 	index fbd1c20a232..c1c5af0b197 100755
> 	--- a/gitweb/gitweb.perl
> 	+++ b/gitweb/gitweb.perl
> 	@@ -4049,7 +4049,13 @@ sub get_page_title {
> 	 	return $title;
> 	 }
> 	 
> 	+sub get_content_type_xml {
> 	+	return 'application/xhtml+xml';
> 	+}
> 	+
> 	 sub get_content_type_html {
> 	+	my ($want_xml) = @_;
> 	+
> 	 	# require explicit support from the UA if we are to send the page as
> 	 	# 'application/xhtml+xml', otherwise send it as plain old 'text/html'.
> 	 	# we have to do this because MSIE sometimes globs '*/*', pretending to
> 	@@ -4057,7 +4063,7 @@ sub get_content_type_html {
> 	 	if (defined $cgi->http('HTTP_ACCEPT') &&
> 	 	    $cgi->http('HTTP_ACCEPT') =~ m/(,|;|\s|^)application\/xhtml\+xml(,|;|\s|$)/ &&
> 	 	    $cgi->Accept('application/xhtml+xml') != 0) {
> 	-		return 'application/xhtml+xml';
> 	+		return get_content_type_html();

I’m guessing that you meant to call get_content_type_xml() here.

> 	 	} else {
> 	 		return 'text/html';
> 	 	}
> 	@@ -4214,6 +4220,7 @@ sub git_header_html {
> 	 
> 	 	my $title = get_page_title();
> 	 	my $content_type = get_content_type_html();
> 	+	my $content_type_xml = get_content_type_html();

I’m also guessing that you meant to call get_content_type_xml() here.

> 	 	print $cgi->header(-type=>$content_type, -charset => 'utf-8',
> 	 	                   -status=> $status, -expires => $expires)
> 	 		unless ($opts{'-no_http_header'});
> 	@@ -4225,7 +4232,7 @@ sub git_header_html {
> 	 <!-- git web interface version $version, (C) 2005-2006, Kay Sievers <kay.sievers\@vrfy.org>, Christian Gierke -->
> 	 <!-- git core binaries version $git_version -->
> 	 <head>
> 	-<meta http-equiv="content-type" content="$content_type; charset=utf-8"/>
> 	+<meta http-equiv="content-type" content="$content_type_xml; charset=utf-8"/>
> 	 <meta name="generator" content="gitweb/$version git/$git_version$mod_perl_version"/>
> 	 <meta name="robots" content="index, nofollow"/>
> 	 <title>$title</title>

With those assumptions in mind, I don’t think that your code is correct if
the problem is that XML documents shouldn't be text/html. Here’s why:

1. XML documents shouldn’t contain http-equiv="content-type" [1].
2. When a meta’s http-equiv attribute equals content-type, then its content
    attribute should equal “the literal string "text/html;", optionally
    followed by any number of ASCII whitespace, followed by the literal
    string "charset=utf-8".” [1]

[1]: <https://html.spec.whatwg.org/multipage/semantics.html#attr-meta-http-equiv-content-type>