From f6ad4074c68103b854b6aa71733a3a7c213da047 Mon Sep 17 00:00:00 2001
From: Yung Thai <32729406+yungthai@users.noreply.github.com>
Date: Sun, 14 Jul 2024 10:42:21 +1000
Subject: [PATCH] feat: restore buffer local keymaps

---
 lua/diffview/vcs/file.lua | 55 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/lua/diffview/vcs/file.lua b/lua/diffview/vcs/file.lua
index 53e04ac5..7e1174d4 100644
--- a/lua/diffview/vcs/file.lua
+++ b/lua/diffview/vcs/file.lua
@@ -15,6 +15,9 @@ local pl = lazy.access(utils, "path") ---@type PathLib
 local api = vim.api
 local M = {}
 
+-- keymaps to restore
+local R = {}
+
 local HAS_NVIM_0_10 = vim.fn.has("nvim-0.10") == 1
 
 ---@alias git.FileDataProducer fun(kind: vcs.FileKind, path: string, pos: "left"|"right"): string[]
@@ -350,8 +353,53 @@ function File:attach_buffer(force, opt)
       state.keymaps = config.extend_keymaps(conf.keymaps.view, state.keymaps)
       local default_map_opt = { silent = true, nowait = true, buffer = self.bufnr }
 
+      R = {}
+
       for _, mapping in ipairs(state.keymaps) do
         local map_opt = vim.tbl_extend("force", default_map_opt, mapping[4] or {}, { buffer = self.bufnr })
+
+        local mode = mapping[1] -- string
+        local name_lhs = mapping[2] -- string
+
+        local lhs_pat = string.format("%s", name_lhs)
+        -- escape special characters for search pattern
+        lhs_pat = string.gsub(lhs_pat, "%[", "%%%[")
+        lhs_pat = string.gsub(lhs_pat, "%]", "%%%]")
+
+        local buf_mappings = api.nvim_buf_get_keymap(self.bufnr, mode)
+
+        for _, buf_km in pairs(buf_mappings) do
+          if buf_km.lhs ~= nil then
+            local result = string.find(buf_km.lhs, lhs_pat)
+
+            if result ~= nil then
+              local rhs = ""
+              if buf_km.rhs ~= nil then
+                rhs = buf_km.rhs
+              else
+                rhs = buf_km.callback
+              end
+              -- save original buffer keymap
+              local orig_km = {
+                mode = mode,
+                lhs = name_lhs,
+                rhs = rhs,
+                opts = {
+                  buffer = self.bufnr,
+                  desc = buf_km.desc,
+                  silent = buf_km.silent,
+                  noremap = buf_km.noremap,
+                },
+              }
+              table.insert(R, orig_km)
+              -- found buffer keymap, so stop searching
+              do
+                break
+              end
+            end
+          end
+        end
+
         vim.keymap.set(mapping[1], mapping[2], mapping[3], map_opt)
       end
 
@@ -387,6 +435,13 @@ function File:detach_buffer()
         end
       end
 
+      -- restore original buffer keymaps
+      for _, km in pairs(R) do
+        if km.opts.buffer == self.bufnr then
+          vim.keymap.set(km.mode, km.lhs, km.rhs, km.opts)
+        end
+      end
+
       -- Diagnostics
       if state.disable_diagnostics then
         if HAS_NVIM_0_10 then