151292 - Text in page displays badly; lines superimposed

Status: RESOLVED DUPLICATE of bug 123330

(Core :: Layout, defect, P3)

Description

[jimsox]

From Bugzilla Helper:
User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X; en-US; rv:1.1a) Gecko/20020610
BuildID:    2002061014

The page displays a bill summary and is supposed to show all the calls. When it
first loads, the summary is fine but not calls appear in each section where they
should. If you go to the printer friendly format, they all show up. Go back to
the standard display and the calls should up as a line of garbage with the text
superimposes on each other.

Reproducible: Always
Steps to Reproduce:
1.Go to Consumer account
2.log in as AT&T long distance customer
3.view current bill

Actual Results:  call history is missing or the display shows the entries
squashed on top of each other

Expected Results:  list of telephone calls with totals. (The header and totals
are fine, just the details are distorted). Works fine in IE and 

I inclose a screen capture.

Comment 1

[jimsox]

Attachment: screen capture of display problem

Comment 2

[Greg K.]

Can't confirm because that URL cannot be accessed. jimsox, can you attach the
HTML to this bug?

Could be a Quartz Text problem. CC'ing Pinkerton.

Comment 3

[jimsox]

Attachment: page source html

Seems to render OK in IE 5.14 and Classic Netscape 4.78.

Comment 4

[Greg K.]

Confirmed using FizzillaCFM/2002061014, although it was necessary to Zoom Larger
then Smaller to see the munged text effect.

Comment 5

[Samir Gehani]

-> Layout

Comment 6

[Greg K.]

Adding qawanted, as this could use a minimized testcase.

Comment 7

[Ed Catmur]

Whooo, nasty.

The page in question is largely composed of HTML generated on-the-fly by
included JavaScript code. It is this HTML which ends up overlapping itself.

I let it load in Mozilla then grabbed the generated HTML (using
document.body.innerHTML), stripped the javascript, and gave that generated HTML
to Opera and IE. Although Opera and IE display the original page properly, they
displayed the Mozilla-generated HTML overlapped as in the original bug.
Conversely, presenting IE-generated HTML to Mozilla gives a page that is
displayed correctly.

However, this does not make it a DOM bug or a JavaScript bug.

The reason for the difference between the Mozilla-generated HTML and
IE-generated HTML is that the javascript contains if-else blocks like the following:

			if((document.all))
			{
				t= "<DIV id=d"+d+i+">";
				t= t + ld_show(a[i]);
				t= t + "</DIV>";
			}
			else
			{
				t= "<DIV CLASS=rel id=d"+d+i+"><DIV CLASS=abs id=d"+d+i+">";
				t= t + ld_show(a[i]);
				t= t + "</DIV></DIV>";
			}

document.all being an IE perversion, this functions as a crude Netscape-tester.
Mozilla falls through to the else block, and generates two nested <div>s, the
outer gets (via an embedded stylesheet) a CSS style of
	{ position: absolute; }
"In the absolute positioning model, a box is removed from the normal flow
entirely (it has no impact on later siblings) and assigned a position with
respect to a containing block."
(http://www.w3.org/TR/REC-CSS2/visuren.html#positioning-scheme) So Mozilla,
correctly, overlaps all the <div>s.

Proof that this is what is happening is that if one places the line

	document.all = true;
	
in the first <script> element, thus faking IE and making the code take the first
if block, the page displays correctly.

Presumably the code was written like this because of some bug or quirk in
Netscape 4.

I don't have Netscape 4 (!) so am unable to confirm that Mozilla-generated HTML
displays correctly in Netscape 4. I'll attach a testcase which hopefully should
display 'correctly' (i.e. no overlapping) in Netscape 4.

Comment 8

[Ed Catmur]

Attachment: Testcase - should overlap in all browsers except Netscape 4

This contains the stylesheet and two bill items generated by JavaScript in
Mozilla.
If I'm right, this will display 'correctly' in Netscape 4 - i.e. the lines will
not overlap.

Comment 9

[Greg K.]

Using Mac Netscape 4.7.9-20011017, nothing is displayed by the testcase; the
content area remains grey and empty.

Comment 10

[Ed Catmur]

Does attachment 2 [details] [diff] [review] display correctly in Netscape 4?

Comment 11

[Greg K.]

Ed, your "Testcase - should overlap in all browsers except Netscape 4" is what I
tested.

Comment 12

[Boris Zbarsky [:bzbarsky]]

*** This bug has been marked as a duplicate of 123330 ***