1100161 - Slow painting with a long line (with <pre>/<nobr>) in an editor, hangs for up to 5 seconds

Status: RESOLVED WORKSFORME

(Core :: Graphics: Layers, defect)

Description

[Nickolay_Ponomarev]

Attachment: testcase

OS X 10.9, using a current nightly.

STR:
1. Open the attached testcase, which looks like this:
    <div contenteditable="">
    <nobr>a very long line ...</nobr>
    [Many <br>s to make the page scrollable vertically]
2. (optional) Scroll to the bottom to see that scrolling is fast
3. Click the contenteditable
    (notice the lag)
4. Try scrolling again
    (scrolling is very laggy)
5, Set layers.enable-tiles = false, restart and try again
    (everything is snappy)

Regression range is 20140903-20140904, on inbound https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=a8f2b6d4fa2c&tochange=c4cb0bd2dbf1 pointing to bug 982338.

Might be a dupe of bug 982433, can't tell.

The original issue was gmail being very slow while replying to a particular message.

This continues to happen even after you turn off spell checking for the editor.

Comment 1

[Nickolay_Ponomarev]

Seems to work fine, both with and without e10s nowadays...