266281 - Text rendering anomalies caused by selecting text, then deselecting by clicking on an unselected area

Status: RESOLVED WORKSFORME

(Core :: Layout: Text and Fonts, defect)

Description

[Daniel Beckham]

User-Agent:       Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7.3) Gecko/20041013 Firefox/0.10
Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7.3) Gecko/20041013 Firefox/0.10

Selecting text in the browser window, then deselecting the text by clicking on a
non-selected area will sometimes cause the text to appear grainy and distorted.
 I've only encountered this in Mac Firefox and usually I only see it at
http://slashdot.org/.  It's fairly easy to reproduce, but not every single time.


Reproducible: Sometimes
Steps to Reproduce:
1. Go to http://slashdot.org/
2. Select several articles worth of text.
3. Deselect the text.

Actual Results:  
When the rendering glitch occures, some of the text in an article will be grainy
and distorted.  Usually the bold or normal text at the end.

Comment 1

[Daniel Beckham]

Attachment: example of the poorly rendered text

In the screenshot attachment, the the last bit of text in the Linux article is
the most affected.

Comment 2

[Geoff Pursell]

My gut feeling about this is that the browser is redrawing text at inappropriate
times, and it's driving me batty.  And it's not just caused by selecting text,
it also shows up when layering absolutely positioned DIVs over other content.

See http://www.cityofbradenton.com/, where if you mouse over "City Departments"
on the left, and then "Bradenton Police Department" (which are pulldown-style
menus), the underlying text "Welcome to our Website" paints itself on top the
menus.  This only happens in Mozilla / Firefox for Mac OS X.  I can't be sure
what specific conditions trigger this, but it also happens for me when selecting
text.

Comment 3

[Geoff Pursell]

Attachment: An example of text drawing itself over a positioned DIV

Here are two screenshots of cityofbradenton.com, showing overzealous text
painting.  It should be noted that this only occurs under somewhat random
circumstances, but is reproducible once you know what they are.  This happens
only in the Mac version.

Comment 4

[Geoff Pursell]

I also forgot to mention that the DIV menus in the example that I gave are built
using <A> tags that are set to display: block, and have :hover classes that
change their background color.  Changing background color seems to have
something in common with text selection...

Comment 5

[Olivier Dony]

I would like to confirm that I've been seeing this on Mac OS X for a long time.

I don't know if that helps but on slashdot you can reproduce this consistenly by
going to the top of the front page. You then hold down the mouse button, and
select text starting for the second article or so, up to the left menu column,
or even through the left border of the browser window. 
Still holding the mouse button down, go back quickly inside the text of the
article. If you keep moving the mouse quickly back in the article, then out
through the left border of the browser, you will see the the text distortion
gets worse and worse.

Releasing the mouse button and re-selecting slowly the distorted text restores
it to normal.

On the other hand if I go to the full article page by clicking on any "Read
More" link, I cannot reproduce this at all, even though the structure of the
page is very similar. Thus there must be something specific on the front page
that trigger this.

This issue is pretty annoying for those of us affected with this habit of
selecting the text of an article while reading it ;-)

Comment 6

[Jamie Diamond]

Confirmed:
Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.8b2) Gecko/20050527 Firefox/1.0+

Comment 7

[Andrew Schultz]

Jamie,
1. bugs should never be confirmed in the "general" component.  
2. this bug belongs in the Core product
3. bugs like this one (display/rendering) should not be confirmed without a
testcase.

Comment 8

[Christopher Kintner]

Attachment: Testcase

Comment 9

[Christopher Kintner]

Attachment: Screenshot of testcase

Comment 10

[Christopher Kintner]

Perhaps someone can add the keyword testcase to this bug.

Comment 11

[Christopher Kintner]

Or more likely mark this bug as a dupe of bug 300982.

Comment 12

[u597032]

See bug 300982