It works because . does not match newlines by default.

i think betterworld knows this =)
the point is, should .* match the empty string between foo\n and the end?

update:

"\n" =~ /\n.*\z/; # matches
"\n" =~ /.*\z/;   # doesn't match. huh?
"\n" =~ /[^\n]*\z/; # matches. ??
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