949879 - Drop support for <pre cols>

Status: RESOLVED FIXED

(Core :: Layout, defect, P4)

Description

[Masatoshi Kimura [:emk]]

This is a non-standard extension derived from Navigator. It is not spec'ed and no other browsers support this. A standard alternative, width attribute, is available.

Comment 1

[Daniel Holbert [:dholbert]]

From a quick glance, I'd expect this would basically just require removing both usages of nsGkAtoms::cols from http://mxr.mozilla.org/mozilla-central/source/content/html/content/src/HTMLPreElement.cpp , right?

Comment 2

[Masatoshi Kimura [:emk]]

(In reply to Daniel Holbert [:dholbert] from comment #1)
> From a quick glance, I'd expect this would basically just require removing
> both usages of nsGkAtoms::cols from
> http://mxr.mozilla.org/mozilla-central/source/content/html/content/src/
> HTMLPreElement.cpp , right?

Basically, yes. We can remove a bit more (usages in ParseAttribute and IsAttributeMapped).

Comment 3

[Masatoshi Kimura [:emk]]

Attachment: Drop support for "cols" attribute of <pre> elements

Comment 4

[Masatoshi Kimura [:emk]]

Try run: https://tbpl.mozilla.org/?tree=Try&rev=9b60d22aa226

Comment 5

[David Baron :dbaron: (⌚️UTC-4, no longer working on Mozilla)]

Comment on attachment 8347216 [details] [diff] [review]
Drop support for "cols" attribute of <pre> elements

r=dbaron

But what other browsers support the width attribute?  It doesn't seem to be spec'd in HTML5 either, though it was in HTML4.  (Unless I'm looking in the wrong places, which I certainly could be.)

Comment 6

[Masatoshi Kimura [:emk]]

(In reply to David Baron [:dbaron] (needinfo? me) (UTC-5) from comment #5)
> But what other browsers support the width attribute?

Other browsers have HTMLPreElement.width property which will reflect the content attribute.

> It doesn't seem to be
> spec'd in HTML5 either, though it was in HTML4.  (Unless I'm looking in the
> wrong places, which I certainly could be.)

It is defined in the HTML5 spec, but in the Obsolete features section.
http://www.whatwg.org/specs/web-apps/current-work/multipage/obsolete.html#HTMLPreElement-partial
Note that this is defined under "Requirements for implementations" subsection, so user agents must implement this as spec'ed despite that authors must not depend on this feature.

HTML5 spec says nothing about the layout effect of the attribute. Actually, it has no visual effect on other browsers. So I was planning to remove the visual effect of the width element, but in a follow-up bug.

Comment 7

[Masatoshi Kimura [:emk]]

> width element
width attribute, of course.

Comment 8

[Masatoshi Kimura [:emk]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/4b78a373acbd

Comment 9

[Masatoshi Kimura [:emk]]

(In reply to Masatoshi Kimura [:emk] from comment #6)
> I was planning to remove the
> visual effect of the width element, but in a follow-up bug.

Filed bug 950737.

Comment 10

[Ryan VanderMeulen [:RyanVM]]

https://hg.mozilla.org/mozilla-central/rev/4b78a373acbd

Comment 11

[Kohei Yoshino]

https://developer.mozilla.org/en-US/Firefox/Releases/29/Site_Compatibility

Comment 13

[j.j.]

https://developer.mozilla.org/en-US/docs/Web/HTML/Element/pre
needs an update then ("cols" and "width" attributes don't work since version 29)

Comment 14

[Jean-Yves Perrier [:teoli]]

Updated