When cursor in on emoji the next character is swallowed in Firefox

[jcubic]

Issue summary

If you click on emoji next character is removed

Expected behavior

Command line stay the same

Steps to reproduce

1. Open devel version of emoji demo https://codepen.io/jcubic/pen/vzGWYj
2. Click on first emoji

Browser and OS

• Firefox

[jcubic]

The problem was that ch unit bug for IE detection return true in Firefox because space was not exactly equal 1ch like in Chrome (there was fraction difference, less then 0.0001).

The second bug was with calculation of the character for the bug (it was single character width for emoji that have 2ch), that's probably present in IE (don't have time to check), the code for IE was called in Firefox.