From 973d814e26db486d6b4d46a3dfed56be612bd759 Mon Sep 17 00:00:00 2001
From: Maksim Odnoletkov <odnoletkov@mail.ru>
Date: Fri, 13 Sep 2019 00:25:21 +0100
Subject: [PATCH] Rudimentary support for diff maps for submodules in status

---
 autoload/fugitive.vim | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/autoload/fugitive.vim b/autoload/fugitive.vim
index 970233b..5513a7b 100644
--- a/autoload/fugitive.vim
+++ b/autoload/fugitive.vim
@@ -2980,7 +2980,15 @@ function! s:StageDiff(diff) abort
   let lnum = line('.')
   let info = s:StageInfo(lnum)
   let prefix = info.offset > 0 ? '+' . info.offset : ''
-  if empty(info.paths) && info.section ==# 'Staged'
+  if info.sub =~# '^S'
+    if info.section ==# 'Staged'
+      return 'Git! diff --no-ext-diff --submodule=log --cached -- ' . info.paths[0]
+    elseif info.sub =~# '^SC'
+      return 'Git! diff --no-ext-diff --submodule=log -- ' . info.paths[0]
+    else
+      return 'Git! diff --no-ext-diff --submodule=diff -- ' . info.paths[0]
+    endif
+  elseif empty(info.paths) && info.section ==# 'Staged'
     return 'Git! diff --no-ext-diff --cached'
   elseif empty(info.paths)
     return 'Git! diff --no-ext-diff'