Bug 13159 – Form Feed should be collapsed rather than turned into zero-width

• Component: Layout and Rendering
• Status: REOPENED

[Jungshik Shin]

Currently, 'Form Feed' (U+000C) is turned to zero-width glyph. However, they should be collapsed like space. See

http://www.w3.org/TR/html401/struct/text.html#didx-white_space-1

Gecko currently renders them as whitespace *without* collapsing them. 

https://bugzilla.mozilla.org/show_bug.cgi?id=373268

[Jungshik Shin]

Related to this bug is bug 13136.

In the page given at the URL, there should be just a single space between 'XXX' and 'XXX'. Currently, there's no space at all because all control characters are turned to a zero-width glyph.

[Eric Seidel (no email)]

It looks like Mozilla closed their bug as "invalid" citing the CSS spec saying that these should be rendered as spaces but not collapsed.

To best understand this bug, we'll need a test case which demonstrates how we behave differently from Gecko or IE.

[Christopher Yeleighton]

Also reported as Bug KDE 292103.

[Robert Hogan]

jshin, is there anything to do here still?

[Robert Hogan]

http://www.w3.org/TR/css3-text/#white-space-rules
http://www.w3.org/TR/CSS21/text.html#white-space-prop

Neither of the specs for whitespace processing treat form feeds as in scope. So IE and Opera are wrong and there's nothing to do here.

[Christopher Yeleighton]

(In reply to comment #5)
> http://www.w3.org/TR/css3-text/#white-space-rules
> http://www.w3.org/TR/CSS21/text.html#white-space-prop
> 
> Neither of the specs for whitespace processing treat form feeds as in scope. So IE and Opera are wrong and there's nothing to do here.

Quoting <URL: http://www.w3.org/TR/CSS21/text.html#white-space-prop >:

UAs must recognize line feeds (U+000A) as newline characters. UAs may additionally treat other forced break characters as newline characters per UAX14. 

Please reopen.

[Robert Hogan]

(In reply to comment #6)
> (In reply to comment #5)
> > http://www.w3.org/TR/css3-text/#white-space-rules
> > http://www.w3.org/TR/CSS21/text.html#white-space-prop
> > 
> > Neither of the specs for whitespace processing treat form feeds as in scope. So IE and Opera are wrong and there's nothing to do here.
> 
> Quoting <URL: http://www.w3.org/TR/CSS21/text.html#white-space-prop >:
> 
> UAs must recognize line feeds (U+000A) as newline characters. UAs may additionally treat other forced break characters as newline characters per UAX14. 
> 
> Please reopen.

Please raise this with www-style so we can resolve this properly.