1348208 - Consider removing -moz-force-broken-image-icon property

Status: RESOLVED WONTFIX

(Core :: CSS Parsing and Computation, enhancement)

Description

[Xidorn Quan [:xidorn] UTC+11]

This property was added in bug 58646, and in bug 672465 reports that it is used to mark missing image with a visible placeholder like IE, via user style sheet, to ease development.

However, as far as I can see, no any other browser is showing such placeholder nowadays. And this property only works on missing images, so it has a pretty low risk on webcompat.

If authors want something like this to help development, it should probably be a pref rather than a CSS property.

Comment 1

[Xidorn Quan [:xidorn] UTC+11]

Attachment: Bug 1348208 part 1 - Remove -moz-force-broken-image-icon.

Review commit: https://reviewboard.mozilla.org/r/121418/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/121418/

Comment 2

[Xidorn Quan [:xidorn] UTC+11]

I'll send the "Intend to unship" if you think we can remove it.

Comment 3

[Xidorn Quan [:xidorn] UTC+11]

https://treeherder.mozilla.org/#/jobs?repo=try&revision=f24c33523c8c22d1e6302322a76d1999e68fd401

Comment 4

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

Yeah, it seems like something we can remove easily.

I had thought there was a style for it in quirks.css, but that doesn't seem to be the case.

Comment 5

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

Comment on attachment 8848486 [details]
Bug 1348208 part 1 - Remove -moz-force-broken-image-icon.

https://reviewboard.mozilla.org/r/121418/#review123470

I think the patch is fine.  It's worth first checking various datasets if we can to see if it has any substantial usage on the Web.  (Since, actually, I guess this is possible, since I think this may be an area where Gecko's behavior differs from other browsers, and this property allows changing it back to match other browsers.  So I think this needs to be looked into a drop more closely than I thought in my previous comment.)

Comment 6

[Xidorn Quan [:xidorn] UTC+11]

There are non-trivial number of results from search which shows some interest of this property, but most of the interest is from users who want Firefox to simulate the IE way.

Nowadays, neither Safari and Chrome, nor Edge shows such placeholder, so Firefox is probably the only browser which can be set to show that. So maybe users are less interested on doing so now.

We can probably introduce a new pref for this, which is easier to maintain and faster than a user stylesheet property.

Comment 7

[Xidorn Quan [:xidorn] UTC+11]

Attachment: Bug 1348208 part 2 - Refactor nsImageFrame::ShouldCreateImageFrameFor a bit.

Review commit: https://reviewboard.mozilla.org/r/121800/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/121800/

Comment 8

[Xidorn Quan [:xidorn] UTC+11]

Attachment: Bug 1348208 part 3 - Add a pref to force showing broken image placeoholder.

Review commit: https://reviewboard.mozilla.org/r/121802/diff/#index_header
See other reviews: https://reviewboard.mozilla.org/r/121802/

Comment 9

[Xidorn Quan [:xidorn] UTC+11]

Comment on attachment 8848486 [details]
Bug 1348208 part 1 - Remove -moz-force-broken-image-icon.

Review request updated; see interdiff: https://reviewboard.mozilla.org/r/121418/diff/1-2/

Comment 10

[Boris Zbarsky [:bzbarsky]]

For what it's worth, the main use case I know of for this is an editor, so something like BlueGriffon.  But obviously an editor app can just set the property.

Have you tested what happens with broken images in contenteditable across browsers?

Comment 11

[Masatoshi Kimura [:emk]]

(In reply to Xidorn Quan [:xidorn] (UTC+10) from comment #0)
> However, as far as I can see, no any other browser is showing such
> placeholder nowadays. And this property only works on missing images, so it
> has a pretty low risk on webcompat.

(In reply to Xidorn Quan [:xidorn] (UTC+10) from comment #6)
> Nowadays, neither Safari and Chrome, nor Edge shows such placeholder, so
> Firefox is probably the only browser which can be set to show that. So maybe
> users are less interested on doing so now.

Your test must have some defect. <https://bugzilla.mozilla.org/show_bug.cgi?id=1348208> displays broken icon for Chrome, Edge, IE11 even though other browsers do not support -moz-force-broken-image-icon.

I think this bug should be WONTFIX because the precondition is wrong.

Comment 12

[Xidorn Quan [:xidorn] UTC+11]

Oh, actually I was wrong, those browsers do show placeholders for broken images, no matter whether it is in a contenteditable.

I guess what I tested was bz's testcase in bug 672465, where no browser other than Gecko shows the placeholder icon, but it seem that is because there is no src specified. When src attribute is specified, all other browsers do show the placeholder icon.

Comment 13

[Masatoshi Kimura [:emk]]

> <https://bugzilla.mozilla.org/show_bug.cgi?id=1348208>
Sorry, the correct URL is:
https://developer.mozilla.org/ja/docs/Web/CSS/-moz-force-broken-image-icon#Examples

Comment 14

[Xidorn Quan [:xidorn] UTC+11]

OK, then given that other browsers do show the icon, let's WONTFIX it... contenteditable could be a problem. I wonder whether we can just have it show the icon whenever it is inside contenteditable, or just always show it when src is set like other browsers.

Comment 15

[Boris Zbarsky [:bzbarsky]]

> I wonder whether we can just have it show the icon whenever it is inside contenteditable

This might be a good idea.

> or just always show it when src is set like other browsers

The other browsers have terrible accessibility behavior: you can't read the alt text unless it's really short.

Also, note that Chrome is planning to change their behavior here to more closely align with us (and the HTML spec, which specs our behavior), not least because of the accessibility issue.

Comment 16

[Florian Scholz (Open Web Docs)]

https://developer.mozilla.org/en-US/docs/Web/CSS/-moz-force-broken-image-icon