Ok, that makes more sense. It's hard to see whitespace, so I didn't notice a tab lurking just before the newline.

Wait... if I can sneak a tab in there, what if someone hid a newline in there, too?

Would you not end up with

  foo\tG
  \t

And break the regex? Or is there absolutely no way to smuggle a \n into the message?

%s inserts the "subject", not the entire commit message. The subject is considered to be the first line of the commit message (I forget if there is a character limit), so a newline would simply be considered the delimiter (and would not appear in the output).

Otherwise, you would be correct --- that would have rendered the check useless.

Ahh, you're right. I get a little paranoid when dealing with user-supplied strings, but usually that's a good thing :)

Absolutely; your critical thought and inquiry is a very positive thing.