418036 - Zero is invalid for -moz-column-width

Status: RESOLVED INVALID

(Core :: CSS Parsing and Computation, defect)

Description

[Mats Palmgren (inactive)]

Follow up from bug 416088 comment 5:

fantasai   2008-02-07 12:28:42 PST
The latest internal spec does indeed specify that [...] column-width and
column-count values must be greater than zero, so zero values should also be
thrown out at parse time.

Comment 1

[Mats Palmgren (inactive)]

Attachment: wip1

Should be a simple enough patch for 1.9 if we want it...

BTW, the code in nsColumnSetFrame::ChooseColumnStrategy() can probably
be simplified further if we can assert that 'availContentWidth' >= 0
or NS_INTRINSICSIZE at the top (can remove numColumns <= 0 checks etc).
Also, the "colWidth = PR_MAX(1, ..." should be necessary, we can assign
it correctly in code above instead.

Also, there's an existing bug in ParsePositiveVariant for
eCSSUnit_Integer, we should at lest fix that bit for 1.9
(to reject -moz-column-count:-1)

Comment 2

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

-count was bug 471341.

Comment 3

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

http://dev.w3.org/csswg/css3-multicol/#cw explicitly allows zero, so this is invalid.

Additionally, nothing in CSS requires open interval range restrictions; all value range restrictions in CSS are closed intervals.  This is important, because things like calc() and animation interpolation (for cubic-bezier() with values outside 0-1) require clamping to the valid range, and you can't clamp to an open interval.  So I would be opposed to a spec that requires an open interval.

Comment 4

[:Ms2ger (he/him; ⌚ UTC+1/+2)]

I'm confused. The computed style allows >= 0, but the spec then goes on to say

> Specified values must be greater than 0. 

Would that trigger your objection?

Comment 5

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

Yes.

Comment 6

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

http://lists.w3.org/Archives/Public/www-style/2011May/0338.html