301913 - Width %tage attribute on img when style disabled is ignored

Status: RESOLVED INVALID

(Firefox :: General, defect)

Description

[Gérard Talbot]

An <img> that has width="100%" should render the image by using 100% of the
available horizontal space, regardless/whether or not View/Page Style/No Style
is selected or not.

"When specified, the width and height attributes tell user agents to override
the natural image or object size in favor of these values.
When the object is an image, it is scaled. User agents should do their best to
scale an object or image to match the width and height specified by the author.
Note that lengths expressed as percentages are based on the horizontal or
vertical space currently available, not on the natural size of the image,
object, or applet."
http://www.w3.org/TR/html4/struct/objects.html#adef-width-IMG

Steps to reproduce:
1- Load this code
<p><img src="https://bugzilla.mozilla.org/mozilla-banner.gif" width="100%"
height="58" alt=""></p>
in a perfectly valid HTML document
2- Toggle View/Page Style/Basic Page Style and No Style
3- Resize the browser window to vary inner viewport dimensions

Actual results in Firefox Deer Park alpha 2 rv 1.8b4 build 20050723 or in
Mozilla 1.8b2 build 2005070105:
When No Style (None) is selected, the Mozilla banner gif uses its physical 600px
width dimension.

Expected results: 
the Mozilla banner gif should use 100% of the available width of the browser
viewport which should be the body width minus 16px for left and right margin
(8px). HTML attribute width="100%" should be honored.

Note 1: After disabling "Fit to window width" and disabling all user styling
options and presentation modes for the user mode in Opera 8.01 build 7642 and
use user mode, the width of the image is scaled proportionally to the window
viewport.

Note 2: It seems that Page Style/ No Style (None) disables several other HTML
attributes in Firefox Deer Park alpha 2 rv 1.8b4 build 20050723 and in Mozilla
1.8b2 build 2005070105. E.g. <table border="10" frame="box" rules="all"
width="100%"> are also all disabled when one uses/selects Page Style/ No Style
(None).

Note 3: I searched carefully Bugzilla database and couldn't find a duplicate; I
searched documentation and couldn't find an explanation for this behavior.

Minimized testcase coming up

Comment 1

[Gérard Talbot]

Attachment: Minimized testcase

Instructions:
Resize browser window and toggle View/Style/No style and Basic Style

Expected results: the Mozilla banner gif image should NOT change width
dimension when toggling from "Basic Page (Default) Style" to "No style" and its
width should be as wide as the body element's horizontal available width (minus
16px due to its left+right margin).

Comment 2

[Aaron Slunt]

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8b4) Gecko/20050724
Firefox/1.0+ ID:2005072402

Feature works as intended (no tags being parsed with styles off).

Comment 3

[Gérard Talbot]

After talks with Bazzi, Mossop and Tonglebeak in firefox channel, I'm resolving
this bug as INVALID.