The “show quoted messages” link breaks other controls

In Sharepoint discussion boards, there is the “show quoted messages” button within each post. It allows to collapse/expand the quoted message.

However this button causes a serious problem:
If you place additional postback sensitive controls on the discussion page, they might break whenever the “show quoted messages” is clicked. This happens, because this button does not perform a valid postback.

Here is a JS based fix:

// workaround for broken show-quoted-text button in discussion board
// see core.js for the original function

function ShowQuotedText(guid, anchor) {
    var frm = document.forms[MSOWebPartPageFormName];
    frm.CAML_ShowOriginalEmailBody.value = frm.CAML_ShowOriginalEmailBody.value.concat(guid);
    if (frm.action.indexOf("#") > 0) {
        frm.action = frm.action.substr(0, frm.action.indexOf("#"));
    }
    frm.action = frm.action.concat("#" + anchor);
    
    // a raw form submit will cause the people editor to break
    //frm.submit();
    // perform a proper postback instead
    __doPostBack('__Page', ''); 
    
    return false;
}

Simply include this snipped in the header of the affected page, or in an external JS file. Just make sure that it is being loaded after core.js.