TinyMCE toolbar doesn't show "Remove Link" button

[scottsousa]

With hashbang URL only
When a link is the only item within a Note widget (randomly occurs)

Steps to replicate:

1.) Create a link
2.) Set the URL in the link modal to "#" (no quotes) or make sure this is the only link in the Note Widget
3.) Select the link (click and drag)
4.) "Remove Link" button doesn't appear

Current Workaround:

1.) Create a link
2.) Set the URL in the link modal to "#" (no quotes) or make sure this is the only link in the Note Widget
3.) Select the link (click and drag)
4.) Click on the "Add Link" button, remove the URL, save

[scottsousa]

If CTRL/CMD + A is used, the "Remove Link" button is displayed if the CTRL/CMD key is held down but "A" is released.

[scottsousa]

This is also occurring sometimes when the link is simply selected, regardless of the position inside of the widget. In this situation, the remove link icon appears if the character before and/or after a link is selected along with the link.

[scottsousa]

This bug is currently not able to be replicated in WordPress 3.9.3, 4.0, or 4.1.