1372836 - [css-break] Images are being fragmented

Status: NEW

(Core :: Layout, defect, P3)

Description

[Timea Zsoldos [:zstimi/tzsoldos], Desktop Release QA]

Attachment: Capture.PNG

[Affected versions]:
Firefox 55.0b1 (Build Id:20170612224034)

[Affected platforms]:
Windows 7 x64.
Windows 8.1 x64.
Ubuntu 14.04 x64.

[Steps to reproduce]:
1.Launch Firefox.
2.Access the http://www.bbc.com/news/world-africa-40246964.
3.From Menu bar go to File → Print Preview.

[Expected result]:
The full image is displayed on a single page.

[Actual result]:
The preview is not working properly, there are images split in two pages. 

[Regression range]:
It is not a regression.

[Additional Information]:
Please observe the attached example file.

Comment 1

[Mats Palmgren (:mats)]

As far as I know, this behavior is intentional.

However, the relevant spec says:
"Some content is not fragmentable, for example many types of replaced
elements [CSS21] (such as images or video), [...] Such content is
considered monolithic"
https://drafts.csswg.org/css-break/#monolithic

It continues to say that:
"Finally, if there are no possible break points [...] the UA may also
fragment the contents of monolithic elements by slicing the element’s
graphical representation."
https://drafts.csswg.org/css-break/#unforced-breaks

Hmm, perhaps we should simply add "img, video, ... { break-inside:avoid; }"
to the UA sheet?  It seems better to allow the author to override
the fragmentation behavior rather than hardcoding it.