From 3cc305e4879075a49b0a5d4f53bb357eaad26892 Mon Sep 17 00:00:00 2001
From: Nick Jensen <nickspoons@users.noreply.github.com>
Date: Fri, 4 May 2018 12:40:24 +1200
Subject: [PATCH 1/2] Do not remap <up>/<down> when already mapped

Check whether a mapping already exists for <up> or <down> before remapping. If either exists already, it indicates an alternate workflow for these keys (e.g. window resizing) that shouldn't automatically be overridden.
---
 autoload/mundo.vim | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/autoload/mundo.vim b/autoload/mundo.vim
index 0729cb5..0b4a588 100644
--- a/autoload/mundo.vim
+++ b/autoload/mundo.vim
@@ -88,8 +88,10 @@ function! s:MundoMapGraph()"{{{
     exec 'nnoremap <script> <silent> <buffer> ' . g:mundo_map_move_newer . " :<C-u>call <sid>MundoPython('MundoMove(-1,'. v:count .')')<CR>"
     nnoremap <script> <silent> <buffer> <CR>          :call <sid>MundoPython('MundoRevert()')<CR>
     nnoremap <script> <silent> <buffer> o             :call <sid>MundoPython('MundoRevert()')<CR>
-    nnoremap <script> <silent> <buffer> <down>        :<C-u>call <sid>MundoPython('MundoMove(1,'. v:count .')')<CR>
-    nnoremap <script> <silent> <buffer> <up>          :<C-u>call <sid>MundoPython('MundoMove(-1,'. v:count .')')<CR>
+    if empty(maparg('<down>', 'n')) && empty(maparg('<up>', 'n'))
+        nnoremap <script> <silent> <buffer> <down>        :<C-u>call <sid>MundoPython('MundoMove(1,'. v:count .')')<CR>
+        nnoremap <script> <silent> <buffer> <up>          :<C-u>call <sid>MundoPython('MundoMove(-1,'. v:count .')')<CR>
+    endif
     nnoremap <script> <silent> <buffer> J             :<C-u>call <sid>MundoPython('MundoMove(1,'. v:count .',True,True)')<CR>
     nnoremap <script> <silent> <buffer> K             :<C-u>call <sid>MundoPython('MundoMove(-1,'. v:count .',True,True)')<CR>
     nnoremap <script> <silent> <buffer> gg            gg:<C-u>call <sid>MundoPython('MundoMove(1,'. v:count .')')<CR>

From c2f4751c516dd7a5a2785addb84f82d48095ca3d Mon Sep 17 00:00:00 2001
From: nickspoons <nickspoon@gmail.com>
Date: Fri, 4 May 2018 22:52:05 +1200
Subject: [PATCH 2/2] Add variable g:mundo_map_up_down

The new variable defaults to 1, so this change won't break UX. Setting
it to 0 prevents remapping of <Up>/<Down>.
---
 autoload/mundo.vim      | 2 +-
 autoload/mundo/util.vim | 4 ++++
 doc/mundo.txt           | 9 +++++++++
 3 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/autoload/mundo.vim b/autoload/mundo.vim
index 0b4a588..ff9085c 100644
--- a/autoload/mundo.vim
+++ b/autoload/mundo.vim
@@ -88,7 +88,7 @@ function! s:MundoMapGraph()"{{{
     exec 'nnoremap <script> <silent> <buffer> ' . g:mundo_map_move_newer . " :<C-u>call <sid>MundoPython('MundoMove(-1,'. v:count .')')<CR>"
     nnoremap <script> <silent> <buffer> <CR>          :call <sid>MundoPython('MundoRevert()')<CR>
     nnoremap <script> <silent> <buffer> o             :call <sid>MundoPython('MundoRevert()')<CR>
-    if empty(maparg('<down>', 'n')) && empty(maparg('<up>', 'n'))
+    if g:mundo_map_up_down
         nnoremap <script> <silent> <buffer> <down>        :<C-u>call <sid>MundoPython('MundoMove(1,'. v:count .')')<CR>
         nnoremap <script> <silent> <buffer> <up>          :<C-u>call <sid>MundoPython('MundoMove(-1,'. v:count .')')<CR>
     endif
diff --git a/autoload/mundo/util.vim b/autoload/mundo/util.vim
index 0fb9649..372c263 100644
--- a/autoload/mundo/util.vim
+++ b/autoload/mundo/util.vim
@@ -61,6 +61,10 @@ call mundo#util#set_default(
             \ 'g:mundo_map_move_newer', 'k',
             \ 'g:gundo_map_move_newer')
 
+call mundo#util#set_default(
+            \ 'g:mundo_map_up_down', 1,
+            \ 'g:gundo_map_up_down')
+
 call mundo#util#set_default(
             \ 'g:mundo_close_on_revert', 0,
             \ 'g:gundo_close_on_revert')
diff --git a/doc/mundo.txt b/doc/mundo.txt
index 458e7ad..12f23a5 100644
--- a/doc/mundo.txt
+++ b/doc/mundo.txt
@@ -25,6 +25,7 @@ CONTENTS                                                      *Mundo-contents*
         3.13 mundo_mirror_graph ........ |mundo_mirror_graph|
         3.14 mundo_inline_undo ......... |mundo_inline_undo|
         3.15 mundo_return_on_revert .... |mundo_return_on_revert|
+        3.16 mundo_map_up_down ......... |mundo_map_up_down|
     4. License ......................... |MundoLicense|
     5. Bugs ............................ |MundoBugs|
     6. Contributing .................... |MundoContributing|
@@ -263,6 +264,14 @@ Set this to 0 to keep focus in the Mundo window after a revert.
 
 Default: 1
 
+------------------------------------------------------------------------------
+3.16 g:mundo_map_up_down                                   *mundo_map_up_down*
+
+By default, <Up> and <Down> are mapped to navigate up and down the undo graph.
+Set this to 0 to prevent these mappings.
+
+Default: 1
+
 ==============================================================================
 4. License                                                      *MundoLicense*