Inconsistent wrapping of last character of first line

[jcubic]

Issue summary

If you type text into the command line, the last character doesn't fit into the first line.

Expected behavior

All lines should have the same number of characters

Actual behavior

The first line doesn't fit all characters

Steps to reproduce

1. Open this demo https://jsfiddle.net/03ngcLwq/
2. type some characters

Additional notes

It seems this behave differently on GNU/Linux and MacOS. On a Mac, the last character jumps.
Reported by @jmacwhyte in #867

[jcubic]

This only happens when the prompt is empty

[jcubic]

Released in 2.37.0