Phantom line in result if file's last line contains LF

[dyng]

I have a file named foo, which contains two only-one-character lines: a and b.

~: cat foo
a
b

If I search this file with ag, I get a result which shows three lines in foo file, and there is a phantom blank line at the last of file.

~: ag -C 3 b
foo
1-a
2:b
3-  <-- This is the phantom line

After some attempts of guess and verification, I figured out that this issue may be related to LF at last line. The phantom line disappeared if I stripped the LF.

I'm not sure this behavior is a feature or a bug of ag, but vim treats LF at last line as an end of line but not a start of new line, therefore it appends LF by default. This causes troubles when searching these files with ag.

In contrast, ack does not append phantom line with same file.

~: ack -C 3 b
foo
1-a
2:b

Thanks in advance.

footnote:

os: OS X v10.10.3
ag: v0.30.0
ack: 2.14