Code block selection does not work in current Firefox

[Kolya]

SMF 2.0.15

The error can be seen here on this board. Try clicking "[Select]" above the code block.

Console error:
IndexSizeError: Index or size is negative or greater than the allowed amount

The reason is feature sniffing aimed at Safari in script.js:

Code Select Expand

// Safari is special!
if (oCurSelection.setBaseAndExtent)
{
var oLastChild = oCodeArea.lastChild;
oCurSelection.setBaseAndExtent(oCodeArea, 0, oLastChild, 'innerText' in oLastChild ? oLastChild.innerText.length : oLastChild.textContent.length);
}
The code in the following else works fine for Chrome and Firefox.

[Sir Osis of Liver]

Confirmed in FF58.

[Illori]

duplicate of https://www.simplemachines.org/community/index.php?topic=553445.0