From f3ccb0c12ee4985b8808f83059830a24cc92821c Mon Sep 17 00:00:00 2001
From: Daniel Hahler <git@thequod.de>
Date: Mon, 30 Oct 2017 22:15:41 +0100
Subject: [PATCH] BufReadObject: handle rev-parse errors

With `:Gdiff ^` on a file that has just been added, you would get an
error via `git rev-parse --verify`:

> fatal: Needed a single revision

The error message is clearer when not using `--verify`:

> fatal: Path 'X' exists on disk, but not in 'SHA'.

The behavior depends on if you use `:set hidden`, where the second
invocation works, as in will open an empty buffer - apparently since it
has been created as "a buffer with read errors" ("x" in `:ls!`) before.

Fixes https://github.com/tpope/vim-fugitive/issues/866.
---
 plugin/fugitive.vim | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/plugin/fugitive.vim b/plugin/fugitive.vim
index 81b519e..3fc0d01 100644
--- a/plugin/fugitive.vim
+++ b/plugin/fugitive.vim
@@ -2749,6 +2749,8 @@ function! s:BufReadObject() abort
       endif
     endtry
 
+    return ''
+  catch /^fugitive: rev-parse/
     return ''
   catch /^fugitive:/
     return 'echoerr v:errmsg'