exp/html: ignore self-closing flag except in SVG and MathML

In HTML content, having a self-closing tag is a parse error unless
the tag would be self-closing anyway (like <img>). The only place a
self-closing tag actually makes a difference is in XML-based foreign
content.

Pass 1 additional test.

R=nigeltao
CC=golang-dev
https://golang.org/cl/6450109

src/pkg/exp/html/parse.go

@@ -999,6 +999,10 @@ func inBodyIM(p *parser) bool {
 			adjustForeignAttributes(p.tok.Attr)
 			p.addElement()
 			p.top().Namespace = p.tok.Data
+			if p.hasSelfClosingToken {
+				p.oe.pop()
+				p.acknowledgeSelfClosingTag()
+			}
 			return true
 		case a.Caption, a.Col, a.Colgroup, a.Frame, a.Head, a.Tbody, a.Td, a.Tfoot, a.Th, a.Thead, a.Tr:
 			// Ignore the token.
@@ -2011,8 +2015,8 @@ func (p *parser) parseCurrentToken() {
 	}
 
 	if p.hasSelfClosingToken {
+		// This is a parse error, but ignore it.
 		p.hasSelfClosingToken = false
-		p.parseImpliedToken(EndTagToken, p.tok.DataAtom, p.tok.Data)
 	}
 }
 

src/pkg/exp/html/testlogs/webkit01.dat.log

@@ -40,7 +40,7 @@ PASS "<svg><title><div>"
 PASS "<svg><title><rect><div>"
 PASS "<svg><title><svg><div>"
 PASS "<img <=\"\" FAIL>"
-FAIL "<ul><li><div id='foo'/>A</li><li>B<div>C</div></li></ul>"
+PASS "<ul><li><div id='foo'/>A</li><li>B<div>C</div></li></ul>"
 PASS "<svg><em><desc></em>"
 PASS "<table><tr><td><svg><desc><td></desc><circle>"
 PASS "<svg><tfoot></mi><td>"