93437 - getComputedStyle returns relative values instead of absolute ones

Status: VERIFIED INVALID

(Core :: DOM: CSS Object Model, defect)

Description

[Stephan Tolksdorf]

getComputedStyle returns relative values for left and top when a nested 
object's position is declared as "absolute", but getComputedStyle should return 
absolute values (relative to the document).
Netscape 6 hadn't this bug.

See http://www.w3.org/TR/2000/REC-DOM-Level-2-Style-20001113/css.html#CSS-
OverrideAndComputed
and the attached testcase.

Comment 1

[Stephan Tolksdorf]

Attachment: Testcase

Comment 2

[Boris Zbarsky [:bzbarsky]]

er... wouldn't getComputedStyle return top and left relative to the containing
block?  That's what those offsets are measured with respect to when those
properties are set....

I believe this is invalid.

Comment 3

[Stephan Tolksdorf]

The DOM specification (see the link in my my bug report) says
--
getComputedStyle:
  (...)
  Return Value: 
    CSSStyleDeclaration
    The computed style. The CSSStyleDeclaration is read-only
    and contains only _absolute_ values.
--
And as I said, that was the behaviour until recently...
 

Comment 4

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

No, this in INVALID.  Sorry for misunderstanding what you were talking about
earlier.  The computed value of 'top' is still '50px', since top means the
offset from the containing block, which in this case is the outer positioned
element and not the viewport (which it is when there is no intervening
positioned element).

Comment 5

[Hixie (not reading bugmail)]

VERIFIED -- 'px' is an absolute unit, as opposed to 'em' and 'ex' which are
relative. That's what the spec is referring to.