From bcf7478e6be9c8e425c0f9fb224821748132d4c3 Mon Sep 17 00:00:00 2001
From: Tim Pope <code@tpope.net>
Date: Wed, 6 Oct 2021 14:44:30 -0400
Subject: [PATCH] Make status buffer diff retrieval asynchronous

Resolves: https://github.com/tpope/vim-fugitive/issues/1856
---
 autoload/fugitive.vim | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/autoload/fugitive.vim b/autoload/fugitive.vim
index 3c106f5..558c6c7 100644
--- a/autoload/fugitive.vim
+++ b/autoload/fugitive.vim
@@ -2742,14 +2742,14 @@ function! fugitive#BufReadStatus() abort
       endfor
     endif
 
-    let diff = {'Staged': [], 'Unstaged': []}
+    let diff = {'Staged': {'stdout': ['']}, 'Unstaged': {'stdout': ['']}}
     if len(staged)
       let diff['Staged'] =
-          \ s:LinesError(['diff', '--color=never', '--no-ext-diff', '--no-prefix', '--cached'])[0]
+          \ fugitive#Execute(['diff', '--color=never', '--no-ext-diff', '--no-prefix', '--cached'], function('len'))
     endif
     if len(unstaged)
       let diff['Unstaged'] =
-          \ s:LinesError(['diff', '--color=never', '--no-ext-diff', '--no-prefix'])[0]
+          \ fugitive#Execute(['diff', '--color=never', '--no-ext-diff', '--no-prefix'], function('len'))
     endif
     let b:fugitive_diff = diff
     if v:cmdbang
@@ -4671,7 +4671,7 @@ function! s:StageInline(mode, ...) abort
     let diff = []
     let index = 0
     let start = -1
-    for line in b:fugitive_diff[info.section]
+    for line in fugitive#Wait(b:fugitive_diff[info.section]).stdout
       if mode ==# 'await' && line[0] ==# '@'
         let mode = 'capture'
       endif
@@ -4795,10 +4795,11 @@ function! s:StageApply(info, reverse, extra) abort
   endif
   let i = b:fugitive_expanded[info.section][info.filename][0]
   let head = []
-  while get(b:fugitive_diff[info.section], i, '@') !~# '^@'
-    let line = b:fugitive_diff[info.section][i]
+  let diff_lines = fugitive#Wait(b:fugitive_diff[info.section]).stdout
+  while get(diff_lines, i, '@') !~# '^@'
+    let line = diff_lines[i]
     if line ==# '--- /dev/null'
-      call add(head, '--- ' . get(b:fugitive_diff[info.section], i + 1, '')[4:-1])
+      call add(head, '--- ' . get(diff_lines, i + 1, '')[4:-1])
     elseif line !~# '^new file '
       call add(head, line)
     endif