IE leak prevention causes content loss

[yaakov]

Short summary

• Interactively (by mouse clicks) add content to a page (with .after(content)).
• Go to another page (e.g. by following a link).
• Hit the back button to come back to the interactive page.

==> Note: The dynamic changes are lost!

This bug is caused by code that prevents memory leaks in IE: when I remove three lines from jQuery.js, the bug disappears.

Example

Note: all example code is attached to this bug report. But you can also look at the live examples on the web.

• I have tested this with Firefox 3. I don't know whether it shows up with other browsers.

• open this page: ​http://www.yaakovnet.net/jQueryBug1/bug.html
• as instructed, click on the text "Click here!"
  • ==> a note (click) should appear. You can click several times.
• now follow the link on the page .... and come back by using your back button.
• Note: the dynamically added (click) notes are gone! This is the bug!

Localizing the problem

The bug is caused by the following lines in jquery.js:

  // Prevent memory leaks in IE
  // And prevent errors on refresh with events like mouseover in
     other browsers
  // Window isn't included so as not to unbind existing unload
     events

  jQuery(window).bind("unload", function() {
    jQuery("*").add(document).unbind();
  });

I created a version jquery-modified.js where the last three lines are commented out. As you can see, using this modified version fixes our problem:

• Go to: ​http://www.yaakovnet.net/jQueryBug1/fixed.html
• Follow the instructions above.
  • ==> Note: the dynamically added text does *not* disappear.

Fixing the problem

Of course, disabling the three lines may cause memory leaks in IE.

• Maybe the call jQuery("*").add(document).unbind() is too general? Leaving some selected events bound may solve our problem without introducing (too many) IE leaks.
• Alternatively --- we should all switch to Firefox.

[yaakov]

html for the bug

[yaakov]

html using jquery-modified.js --- show test without the bug

[yaakov]

jquery.js with three lines disabled --- this removes the bug.

[yaakov]

a plain html page referenced by the html examples

[flesler]

This removal won't be taken out. It's very common to remove all the bindings on window unload, so it's expected that a back action will face these problems.

Still, I'll leave this open for now.

[flesler]

1.3 will do this much faster, that should be enough. If the problem persist, do reopen or file a new ticket.