[csswg-drafts] [css21] 9.4.3 Relative positioning(getComputedStyle does not handle over-constrained properties correctly)

deokjinkim has just created a new issue for 
https://github.com/w3c/csswg-drafts:

== [css21] 9.4.3 Relative positioning(getComputedStyle does not handle
 over-constrained properties correctly) ==
Hello, 

I have a question about css 2.1 
spec.(https://www.w3.org/TR/2011/REC-CSS2-20110607/visuren.html#relative-positioning)

* Background
I'm working on blink engine as deokjin81.kim@samsung.com.
As I know, getComputedStyle does not handle over-constrained 
properties correctly.
So I implemented 
it(https://bugs.chromium.org/p/chromium/issues/detail?id=601118) 
according to spec on blink engine.

* 
Spec(https://www.w3.org/TR/2011/REC-CSS2-20110607/visuren.html#relative-positioning)
Below paragraphs(from spec) describe detail operation to handle 
over-constrained properties.

If neither 'left' nor 'right' is 'auto', the position is 
over-constrained, and one of them has to be ignored. If the 
'direction' property of the containing block is 'ltr', the value of 
'left' wins and 'right' becomes -'left'. If 'direction' of the 
containing block is 'rtl', 'right' wins and 'left' is ignored.

The 'top' and 'bottom' properties move relatively positioned 
element(s) up or down without changing their size. 'Top' moves the 
boxes down, and 'bottom' moves them up. Since boxes are not split or 
stretched as a result of 'top' or 'bottom', the used values are 
always: top = -bottom. If both are 'auto', their used values are both 
'0'. If one of them is 'auto', it becomes the negative of the other. 
If neither is 'auto', 'bottom' is ignored (i.e., the used value of 
'bottom' will be minus the value of 'top').

* Question
The spec text uses the verb “becomes.” I don’t know if this means that
 either 1) the rendering and the computed style should reflect this, 
or 2) just the rendering should reflect this.
Current implementation reflects second option("2) just the rendering 
should reflect this.").
I would like to know exact meaning of the verb "becomes.".  Which one 
did you intend, 1) or 2)?

Thank you in advance,
Deokjin Kim

Please view or discuss this issue at 
https://github.com/w3c/csswg-drafts/issues/190 using your GitHub 
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Received on Wednesday, 15 June 2016 04:49:51 UTC