247848 - margin of body in userContent.css affects standalone images/plugins

Status: NEW

(Core :: CSS Parsing and Computation, defect)

Description

[Ozan Ayyüce]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7) Gecko/20040616
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7) Gecko/20040616

The margin-top, margin-bottom etc attributes of body in userContent.css affect
content different from html too. With certain values of these attributes this
leads to problems.

For example, a margin-bottom of 700px is used ^1. jpg-images opened in the
browser apart from any html-framework nevertheless have a margin of 700 pixels
under them filled with nothing. When the picture is scaled to fit the browser
window the margin stays, making the combination of pixture and margin to be
scaled to fit the window and thus the picture to be scaled to a tiny size.

This affects plugins too, like flash or pdf. Since documents not embedded in
html are scaled to fit the window too, the same problem as with images appears:
the combination of the rendering of the plugin-document and the margin is scaled
to fit the window, making the plugin-document appear tiny and unusable.



Reproducible: Always
Steps to Reproduce:
1. Put 
-----
body
{ 
    margin-bottom:600px !important;
}
----
   into userContent.css and make sure it is in effect by restarting Mozilla.
2. Open a pdf or flash document or an image not embedded in html
3. When an image is opened make sure it is scaled to fit the browser window by
clicking it. (enabling the option to do this might be neccessary)

Actual Results:  
The pdf or flash document or image is either rendered tiny.


Expected Results:  
Either:
The body-margin should not be applied to non-html-content at all (preferred)
or
Scaling to fit the browser window should not include the margin.

^1: This is useful in the way that when hitting spacebar or pagedown the
document is scrolled down actually an entire page even when reaching the end of
a html-document. This prevents an interruption of the reading flow. (There is a
seperate bug describing this problem)

Comment 1

[Boris Zbarsky [:bzbarsky]]

The basic issue is that those _are_ HTML documents.  We synthesize an HTML
document and embed the standalone content in it to show it....

Perhaps userContent.css should not be applied at all to MediaDocument instances?