Consider this command:
foo $'foo \' bar'
As far as the bash core is concerned, this command has one argument
word. But readline, for completion, splits it up into three words:
0: foo
1: $'abc \'
2: bar'
Shouldn't we be splitting the command line into the same number of words?
> The parent shell (the one that enabled -e) should be the one to make the
> decision about whether or not the shell exits. The exit status of the
> command substitution doesn't make a difference except in one special case,
> so inheriting errexit and exiting (possibly prematurely) doesn't really
