1515267 - execCommand('bold') behavior is different from Blink

Status: UNCONFIRMED

(Core :: DOM: Editor, defect, P3)

Description

[Dalius Dobravolskas]

Attachment: editor.html

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:64.0) Gecko/20100101 Firefox/64.0

Steps to reproduce:

I have contentEditable with normal font-weigth set to 500. 


Actual results:

execCommand('bold') is not working.


Expected results:

execCommand('bold') should be working like in other browsers or documentation should state that font-weight affects 'bold' command behavior. It is almost impossible to figure that out. Attaching editor.html that is sample taken from MDN and only has "font-weight: 500" line was added. This seems to be related to https://bugzilla.mozilla.org/show_bug.cgi?id=833889 that was marked as wontfix.

Neither of these two documents mention that:

* https://developer.mozilla.org/en-US/docs/Web/API/Document/execCommand

* https://developer.mozilla.org/en-US/docs/Web/Guide/HTML/Editable_content

Comment 1

[Kagami Rosylight [:saschanaz] (they/them)]

Note that Firefox thinks font-weight: 500 is bold enough and tries to un-bold it, while Chrome only does the same thing starting from font-weight: 600. It doesn't depend on how the font actually renders; for example, font-weight: 550 for Times New Roman means a bold text but Chrome still tries to make it bold again, getting no visual change just as this bug describes.

Comment 2

[Kagami Rosylight [:saschanaz] (they/them)]

This is exactly the behavior difference described in the execCommand spec.

Masayuki, should Gecko behavior match Blink one? The spec author seems to think Blink one better matches intuition.

Comment 3

[Masayuki Nakano [:masayuki] (he/him)(JST, +0900)(away until 10/14)]

Well, if Safari is also using same threshold, changing our threshold must be better for web-compat, but I'm not sure about backward compatibility and usual font rendering result. Perhaps, I think that we should file new spec issue and ask other vendors if our behavior is better for font rendering result.