Steps to reproduce the issue

1- Use a fresh joomla install
Tip: Go to https://demo.joomla.org/ and launch a "Quick Joomla! Test Drive"
2- On chrome go to one article and mouseover the breadcumb link

Expected result

Mouseover link only in text.

Actual result

Link in text and in a space before/after the link.

System information (as much as possible)

Joomla 3.4.5

Additional comments

The problem is mod_breadcumbs template https://github.com/joomla/joomla-cms/blob/staging/modules/mod_breadcrumbs/tmpl/default.php#L51.

If you use tabs or spaces inside the HTML anchor tag (a) it will (at least chrome) render extra spaces space with link.

Solution

Do not use tabs or spaces inside the anchor tag (a).
If agreed i can make a PR to solve this.