995156 - Hang typing into the address bar after visiting very long URLs

Status: RESOLVED WORKSFORME

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

Description

[Jonathan Watt [:jwatt]]

I've recently been experiencing occasional 100% CPU hangs when typing into the address bar, forcing me to kill and restart Firefox. Worse is that from that day forward typing the same two or three character sequence into the address bar will cause Firefox to hang again.

It turns out this happens after you visit a very long URL, when you later type into the address bar an the suggestion list tries to include that long URL.

In my case this most recently happened after visiting a reftest-analyzer link from TBPL results. More specifically for a Windows "R" failure from:

  https://tbpl.mozilla.org/?tree=Try&rev=cc042860ee89

The URL was almost 8 MB in length, and we end up hanging in text run code trimming white space when I type "que" into the address bar.

To stop the hangs from occurring I had to figure out which long URL I had visited and then go into |History > Show All History| and search for and delete that URL so that it would no longer appear in the address bar suggestions list.

Comment 1

[Jonathan Watt [:jwatt]]

This is in a release build.

Comment 2

[Jonathan Watt [:jwatt]]

While limiting the length of the autocomplete results would prevent us hitting this bug, this issue should be considered separately. Something is rotten in the textrun code if we're hanging on 8 MB strings.

Comment 3

[Jonathan Kew [:jfkthame]]

Yeah, that sounds like we have an inefficiency somewhere. Could you grab a profile of the hang?

Comment 4

[Jonathan Watt [:jwatt]]

Attachment: profile as text file

Comment 5

[Jonathan Watt [:jwatt]]

Attachment: profile as Instruments .trace.zip

Comment 6

[:Gavin Sharp [email: [e-mail]]]

Bug 907001 is on file for essentially the same issue, but is currently a front-end bug tracking limiting the results we display.

Comment 7

[Negritas Sergiu, Desktop QA]

Hello! I will close this issue since there was no activity in the past years and also that this issue doesn't occur in the latest fx versions of firefox. If this issue is still valid please feel free to reopen it.

Thank you and have a nice day!