Fix serialization of HTML void elements when they have children

https://bugs.webkit.org/show_bug.cgi?id=162418

Reviewed by Darin Adler.

LayoutTests/imported/w3c:

Rebaseline W3C test now that more checks are passing.

* web-platform-tests/html/syntax/serializing-html-fragments/serializing-expected.txt:

Source/WebCore:

Fix serialization of HTML void elements when they have children.

Void elements (such as <hr>) cannot have a closing tag. When
encountering them, we would properly not serialize the void
element's children (if it had any). However, we would incorrectly
append an end tag (because the element technically has children).

Relevant specification:
- https://html.spec.whatwg.org/#html-fragment-serialisation-algorithm

In particular, this part:
""
If current node is an area, base, basefont, bgsound, br, col, embed,
frame, hr, img, input, keygen, link, meta, param, source, track or wbr
element, then continue on to the next child node at this point.
""

Firefox matches the specification.

No new tests, rebaselined existing test.

* editing/MarkupAccumulator.cpp:
(WebCore::MarkupAccumulator::serializeNodesWithNamespaces):


Canonical link: https://commits.webkit.org/180410@main
git-svn-id: https://svn.webkit.org/repository/webkit/trunk@206266 268f45cc-cd09-0410-ab3c-d52691b4dbfc

LayoutTests/imported/w3c/ChangeLog

@@ -1,3 +1,14 @@
+2016-09-22  Chris Dumez  <cdumez@apple.com>
+
+        Fix serialization of HTML void elements when they have children
+        https://bugs.webkit.org/show_bug.cgi?id=162418
+
+        Reviewed by Darin Adler.
+
+        Rebaseline W3C test now that more checks are passing.
+
+        * web-platform-tests/html/syntax/serializing-html-fragments/serializing-expected.txt:
+
 2016-09-22  Youenn Fablet  <youenn@apple.com>
 
         Sync web-platform-tests up to revision 3801ab5