Analysis and quick-fix via configuration parameter are documented in the original JIRA: ICE-8535.

Arturo Zambrano added a comment - 06/Sep/12 01:21 PM
Added new parameter 'com.icesoft.faces.IE8DisableModalFrame' to determine whether to show the modal frame or not in IE8, in order to prevent this memory leak. Committed fix at revision 30711 in the maintenance branch and at revision 30712 in the trunk.

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Ken Fyten added a comment - 06/Sep/12 05:39 PM
Re-opening to see if we can solve this without a config param for 3.2 final.

Need to understand why the modal layer causes the IE8 memory leak, perhaps we can adjust it directly and then remove the special flag.

Cleanup supposed to be done by Ice.modal.stop(). This function existed as early as 2006. (Check-in comment was "Fix potential memory leak.")

Apart from checking if stop() is doing its job properly, see screenshot-01.png for some other complications.

iframe still exists in onElementUpdate phase, therefore should use onElementUpdate instead of onElementRemove. But changing to use onElementUpdate doesn't seem to help a bit, even though debugging of stop() in IE8 shows it does execute the iframe cleanup code:

Event.stopObserving(window, "resize", iframe.resize);
Event.stopObserving(window, "scroll", iframe.resize);
iframe.resize = null;
iframe.parentNode.removeChild(iframe.nextSibling);
iframe.parentNode.removeChild(iframe);

Modified Ice.modal.stop() function to clear the callbacks registered on the iframe's document and window objects (used for mouse and keyboard event draining). This in effects solves the memory leak ( see http://support.microsoft.com/kb/2714930 ).
Also, modified PanelPopupRenderer to use ice.onElementUpdate registration function instead of ice.onElementRemove for the callback that invokes Ice.modal.stop(), this way the callback is invoked before the update is applied having thus the chance to still access the iframe it needs to work on.

Found a regression with these changes. Customer has an ace:fileEntry used in a modal ice:panelPopup. When the popup is closed with an h:commandButton, the underlying input components tabindex remains at -1 making them non-functional. If the fileEntry is removed or the h:commandButton is changed to an ice:commandButton this behavior is not need. The h:commandButton is a different button than what is used for the upload. I'll attach a basic test case showing this issue.

Attached test case that shows recent issue.

Steps:

• Load welcomeICEfaces.jsf
• Click on the Open Button, modal panelPopup is shown that includes an ace:fileEntry, Upload button, and two Cancel buttons.
• Clicking on the "ICE - Cancel" button closes the popup and the popup can be reoponed.
• Clicking on the "H - Cancel" button closed the popup but it can't be reopened.
• Looking at the source of the Open button, its tabindex is set to -1 even though the modal layer is gone.

The recent issue is caused by the use of ace:fileEntry, this component disables the form submit capturing and it does its own form submit. When the form submit does not go through jsf.ajax.request function the ice.onElementUpdate callbacks are not invoked, causing the onclick, onkeypress, onleyup and onkeydown callbacks that block the interaction with elements underneath the modal overlay to not be cleared when the modal popup is closed. This is the reason why the "Open" button does not respond, the click events are blocked by the overlay iframe (which is still present but hidden).

Reverting the changes for PanelPopupRenderer to register the iframe cleanup code with ice.onElementRemove is not possible because ice.onElementRemove callbacks are invoked after the updates are applied, too late for the callback code to cleanup the memory leak inducing callbacks.

Changing the file entry renderer to do its own form submit only when the "Upload" button is clicked is not possible because the button is rendered by a plain h:commandButton component.

The simplest and quite correct workaround is to add the f:ajax or ace:ajax tag to the "Cancel" h:commandButton. This way the ICEfaces form submit is executed and ice.onElementUpdate callbacks are invoked. Also when the "Cancel" button is clicked the file upload will not proceed, this is the correct part since you don't want to upload the file but to cancel instead.