510063 - [HTML5][Patch] Extra space appears on musica.com due to <form> foster-parenting

Status: RESOLVED FIXED

(Core :: DOM: HTML Parser, defect, P1)

Description

[Jonathan Griffin (:jgriffin)]

Attachment: testcase (HTML)

On the site musica.com (Alexa ranking 413), extra space occurs in the layout in two separate places (just below the title graphic, and above the "Buscador de Musica" search table), when the HTML5 parser is enabled.  The site renders OK on FF 3.5, Safari, and IE8.

The issue occurs because the site uses <form> elements inside <tr> elements, which the HTML5 parser foster-parents to the table's parent, and the <form> element, even though empty, produces some blank vertical space.

Simplified testcase attached.

Comment 1

[Jonathan Griffin (:jgriffin)]

This issue also occurs on amazon.com, on the bottom of any product page, in the "Feedback" section.  E.g., http://www.amazon.com/Echoes-Dead-Johan-Theorin/dp/0385342217/ref=pd_cp_b_1.

The cause is the same:  a <form> element is foster-parented out of a <table> element, and produces some empty vertical space, whereas without the HTML5 parser, the <form> stays in the <table> and is simply not rendered.

Comment 2

[Henri Sivonen (:hsivonen) (away from Bugzilla until 2026-04-13)]

Filed spec bug:
http://www.w3.org/Bugs/Public/show_bug.cgi?id=7978

Comment 3

[Jonas Sicking (:sicking) No longer reading bugmail consistently]

This is excellent feedback! Please do note if you (or anyone else) finds more sites where this is a problem. I'm sure this can be fixed in the HTML parser, but if only a few sites are affected it might be worth keeping things simpler by keeping them as they are.

After all, the sites are still fully functional, just some rendering quirks.

Comment 4

[Henri Sivonen (:hsivonen) (away from Bugzilla until 2026-04-13)]

http://html5.org/tools/web-apps-tracker?from=4287&to=4288
(The spec change seems to have a copy-paste error in it.)

Comment 5

[Henri Sivonen (:hsivonen) (away from Bugzilla until 2026-04-13)]

Patch attached to bug 502804.

Comment 6

[Henri Sivonen (:hsivonen) (away from Bugzilla until 2026-04-13)]

http://hg.mozilla.org/mozilla-central/rev/d8643125df76