TYPO3 Core

Udo Leimberger wrote:

Using the backend while Firebug is active, the console shows error:

Handler is undefined in line 3966 in prototype.js

Quick fix:
Change line 3966 in typo3/contrib/prototype/prototype.js
From:
handler.call(element, event);

To:
if (handler) {
handler.call(element, event);
}

I can confirm this issue, but I'm not sure, whether it's a good idea to modify third party libraries.
Could you figure out, why the handler is undefined?

The core problem is the prototype Event.observe(element,'resize' call.
So, if you resize the browser or i.e. resize firebug-window you will get this handler is undefined error.

I think there must be an (old) call like this:
Event.observe(window, 'resize', TYPO3BackendToolbarManager.positionMenu('backend-search-menu'));

where backend-search-menu is the id of the controll which doesn't exist in the html code or was not created till the call fired.

if I have a litte time, I try to locate the problem.

This observe resize is used at the following places:

./typo3/js/backendsearch.js: Event.observe(window, 'resize', TYPO3BackendToolbarManager.positionMenu('backend-search-menu'));
./typo3/js/clearcachemenu.js: Event.observe(window, 'resize', TYPO3BackendToolbarManager.positionMenu('clear-cache-actions-menu'));
./typo3/js/shortcutmenu.js: Event.observe(window, 'resize', TYPO3BackendToolbarManager.positionMenu('shortcut-menu'));
./typo3/js/workspacemenu.js: Event.observe(window, 'resize', TYPO3BackendToolbarManager.positionMenu('workspace-selector-menu'));
./typo3/sysext/opendocs/opendocs.js: Event.observe(window, 'resize', TYPO3BackendToolbarManager.positionMenu('tx-opendocs-menu'));
./typo3/sysext/sys_action/toolbarmenu/tx_sysactions.js: Event.observe(window, 'resize', TYPO3BackendToolbarManager.positionMenu('tx-sys-action-menu'));
./typo3/sysext/workspaces/Resources/Public/JavaScript/workspacemenu.js: Event.observe(window, 'resize', TYPO3BackendToolbarManager.positionMenu('workspace-selector-menu'));

Patch set 1 of change Ifb2db858d7075f4fd714d737576189c0e1efc5a5 has been pushed to the review server.
It is available at http://review.typo3.org/5634

Patch set 2 of change Ifb2db858d7075f4fd714d737576189c0e1efc5a5 has been pushed to the review server.
It is available at http://review.typo3.org/5634

Patch set 3 of change Ifb2db858d7075f4fd714d737576189c0e1efc5a5 has been pushed to the review server.
It is available at http://review.typo3.org/5634

Patch set 4 of change Ifb2db858d7075f4fd714d737576189c0e1efc5a5 has been pushed to the review server.
It is available at http://review.typo3.org/5634

Patch set 1 of change I15f3bab4c3c59c5c96633423ac7cd0ebd1736a1a has been pushed to the review server.
It is available at http://review.typo3.org/5694

I think that one is worth to go even into the next 4.4!