IVLE text editor suffers Warning: Unresponsive Script when opening files 270 lines or longer in Firefox 12..

[Marco Lui]

Steps to reproduce:
1) Create a file with 270 lines
2) Open the file in the IVLE text editor using Firefox 12.0 on Win7

Expected outcome:
1) Able to edit file in IVLE text editor

Actual outcome:
1) Firefox unresposive for ~5 seconds, followed by:

A script on this page may be busy, or it may have stopped responding. You can stop the script now, or you can continue to see if the script will complete.

Script: http://ivle.informatics.unimelb.edu.au/+media/+1.0.2/+external/codemirror/js/codemirror.js:381

Also tested:
1) Google Chrome instead of Firefox - issue not present

Not tested:
1) Operating systems other than Win7
2) Firefox versions other than 12.0
3) Any other browser

What is particularly odd is that this starts happening at exactly 270 lines. Files with 269 lines are fine. Google chrome has no problems with files 5000 lines long.

[Matt Giuca (mgiuca)]

Thanks for the report. If you click "Continue" does it eventually complete, or does it circle back around and crash again?

(Note that CodeMirror is not our code so we probably can't do much about it, but we'll take it as a bug anyway.)

[Marco Lui (saffsd)]

No worries. "Continue" causes it to loop back around as far as I can tell. I've hit it thrice so far.

http://ivle.informatics.unimelb.edu.au/+media/+1.0.2/+external/codemirror/js/codemirror.js doesn't seem to carry a version number. Is it bundled with IVLE? If so, is there a chance a newer version may fix the issue?

[William Grant (wgrant)]

It's not bundled with the IVLE code. The Unimelb production system uses the codemirror .deb package from <https://launchpad.net/~unimelb-ivle/+archive/production/+packages>, which is trivial to update. But I'm not sure how much the API has changed since then, so a newer version may take some work to integrate.