Unexpected double newline in shell.sed() output

[nfischer]

Node version (or tell us if you're using electron or some other framework):

All?

ShellJS version (the most recent version/Github branch you see the bug on):

tip-of-tree (GitHub main branch)

Operating system:

All?

Description of the bug:

I think there's a double-newline in sed() outupt there shouldn't be:

shelljs/test/sed.js

Lines 170 to 173 in 1a8e38d

	const result = shell.sed('-i', 'test', 'hello', `${t.context.tmp}/file*.txt`);
	t.falsy(shell.error());
	t.is(result.code, 0);
	t.is(result.toString(), 'hello1\n\nhello2\n'); // TODO: fix sed's behavior

Need to investigate more and figure out what's going on here.

Example ShellJS command to reproduce the error:

The \n\n between "hello1" and "hello2" should probably only be a single \n.

shelljs/test/sed.js

Lines 170 to 173 in 1a8e38d

	const result = shell.sed('-i', 'test', 'hello', `${t.context.tmp}/file*.txt`);
	t.falsy(shell.error());
	t.is(result.code, 0);
	t.is(result.toString(), 'hello1\n\nhello2\n'); // TODO: fix sed's behavior