352307 - pre blocks do not paint well with really large amounts of text and overflow:auto

Status: RESOLVED DUPLICATE of bug 301637

(Core :: Layout, defect)

Description

[Daniel O'Connor]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1b2) Gecko/20060821 Firefox/2.0b2
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1b2) Gecko/20060821 Firefox/2.0b2

Basically, I have a <pre> with about 10,000 lines of rubbish in it; and overflow:auto set on the pre.

Scrolling down the page about half way, the text is no longer rendered, only a large gray square. Scrolling again repaints better.

Reproducible: Always

Steps to Reproduce:
1. Open testcase
2. Scroll until you get half way down or so. You should be able to see a large gray / black square.
3. When you release the mouse cursor, it tries to paint again, but still has the square.
4. Scrolling up / down then back again to the same spot clears up the gray square.

Actual Results:  
A large patch of screen isn't rendered

Expected Results:  
A large patch of screen is rendered

Comment 1

[Daniel O'Connor]

Attachment: Testcase

Comment 2

[Daniel O'Connor]

Attachment: Screenshot of problem

Comment 3

[Brian Polidoro]

*** This bug has been marked as a duplicate of 301637 ***