63298 - Emulating frames with CSS

Status: VERIFIED INVALID

(Core :: Layout, defect)

Description

[tapio.markula]

I tested, if Mozilla could emulate nested framesets with HTML and BODY elements with following CSS:
 
 html{height:600px;overflow:auto;}
 body.mielipide {max-width:600px;height:300px;overflow:auto;margin:auto}
 
 In my mind Mozilla should put equal margin above and below the BODY, but it
 doesn't work. margin:auto works in horizontal direction, but NOT in
 vertical direction.
 
 I addmit, that Mozilla is qood, but the IFRAME emulation is not perfect in
 the build, which I have tested. This implementation is in fact unnecessary.

Comment 1

[Henri Sivonen (:hsivonen)]

From the spec section "10.6.3 Block-level, non-replaced elements in normal flow, and 
floating, non-replaced elements":
"If 'top', 'bottom', 'margin-top', or 'margin-bottom' are 'auto', their computed value is 0."
http://www.w3.org/TR/REC-CSS2/visudet.html#q17

Hence, the computed value of the margin-top property is 0 in the described case.

Comment 2

[Hixie (not reading bugmail)]

Reporter: could you please read the Bug Writing Guidelines at:
   http://www.mozilla.org/quality/bug-writing-guidelines.html
...to see the kinds of information we need in a bug report. Also, please use the
Bugzilla Helper when filing future bug reports. The Helper can be found at:
   http://www.mozilla.org/quality/help/bug-form.html
Thanks for your help in testing Mozilla.