title: Why `git blame -e` sometimes print filenames and sometimes don't?
body: <p>See the following example (in the LLVM source tree cloned from <a href="https://github.com/llvm-mirror/llvm" rel="nofollow noreferrer">https://github.com/llvm-mirror/llvm</a>). Why sometimes the file names are printed and sometimes don't? Thanks.</p>
  
  <pre><code>llvm$ git blame -e  ./include/llvm/IR/Instruction.h
  3a8b0f00e6d2 include/llvm/Instruction.h    (&lt;sabre@nondot.org&gt;                2002-09-10 15:36:11 +0000   1) //===-- llvm/Instruction.h - Instruction class definition -------*- C++ -*-===//
  9769ab22265b include/llvm/Instruction.h    (&lt;brukman+llvm@gmail.com&gt;          2005-04-21 20:19:05 +0000   2) //
  6fbcc26f1460 include/llvm/Instruction.h    (&lt;criswell@uiuc.edu&gt;               2003-10-20 20:19:47 +0000   3) //                     The LLVM Compiler Infrastructure
  llvm$ git blame -e ./lib/Transforms/Hello/Hello.cpp | head -n 3
  180e568a7058 (&lt;sabre@nondot.org&gt;         2002-08-08 20:10:38 +0000  1) //===- Hello.cpp - Example code from "Writing an LLVM Pass" ---------------===//
  fd93908ae8b9 (&lt;brukman+llvm@gmail.com&gt;   2005-04-21 23:48:37 +0000  2) //
  b576c94c15af (&lt;criswell@uiuc.edu&gt;        2003-10-20 19:43:21 +0000  3) //                     The LLVM Compiler Infrastructure
  </code></pre>