How to reproduce:
1. Set "Edit mode" to "shellscript"
2. Add a line with this text (based on <https://github.com/l0b0/tilde/blob/6832f9dd56d3918aa386aff74d57f22490deb75d/.bash_aliases#L501>): echo 'foo\'
3. Add more lines after that one
The following lines are colored as if they were part of the single-quoted `sed` command, but they should not be. To verify in any POSIX shell, run `echo 'foo\'` - It will print the literal "foo\" (without quotes), and not prompt for further text.