The helper function replicate in mediawiki.language.numbers.js has an endless loop:

		while (num) {
			buf.push( str );
			str += str;
		}

Steps to reproduce (make sure you have no unsaved changes in your browser if you need to kill it!):

1. Open the JavaScript console
2. Load the module with mw.loader.load('mediawiki.language.numbers');
3. After it has loaded, execute mw.language.commafy(1234.567, '#0.###');

This should return something like '1234,567' (depending on the language of the wiki), but instead triggers that endless loop, which will either freeze the browser or produce an error message like "InternalError: allocation size overflow".

Version: 1.24rc
Severity: normal