fish reader loses it when there's a blank line in an indented block

[mqudsi]

Paste the following at the prompt:

	clang --autocomplete='--std=' |

		string replace -r -- '^([^ ]+)\s*(.*)' '$1\t\$2'

Observe that the text on the first row does not match what was pasted. Try navigating back and forth/up and down with the arrow keys on the different lines. Press ^C and observe that the prompt isn't cleared.

fish loses it.

https://asciinema.org/a/TsAwarGwkZTpVQL3aQ72Dkvkr

[faho]

Simplified test case:

commandline -i -- "" \ta

An empty line, then a line starting with a tab character.

[mqudsi]

Note that I reverted the commit that disabled ONLCR due to a very similar issue. I may have been too hasty to revert it.

[mqudsi]

Thanks for the test case, @faho. I was able to confirm this behavior going back to fish 2.0.