From 9295ac5d1d4b556247f0b529d962392f354bc9a7 Mon Sep 17 00:00:00 2001
From: Wei Meng <exdream@live.cn>
Date: Thu, 3 Jul 2025 15:28:19 +0800
Subject: [PATCH 1/2] fixes for full diff mode

- switch off diff mode of source buffer on exit
- fix off-by-one error when patching lines
- set correct filetype for diff buffer
---
 lua/CopilotChat/config/mappings.lua | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/lua/CopilotChat/config/mappings.lua b/lua/CopilotChat/config/mappings.lua
index baf2f82c..2f64710e 100644
--- a/lua/CopilotChat/config/mappings.lua
+++ b/lua/CopilotChat/config/mappings.lua
@@ -349,6 +349,8 @@ return {
       if copilot.config.mappings.show_diff.full_diff then
         local modified = utils.buf_valid(diff.bufnr) and vim.api.nvim_buf_get_lines(diff.bufnr, 0, -1, false) or {}
 
+        opts.syntax = diff.filetype
+
         -- Apply all diffs from same file
         if #modified > 0 then
           -- Find all diffs from the same file in this section
@@ -376,7 +378,7 @@ return {
             end
             local change_lines = vim.split(file_diff.change, '\n')
             for i, line in ipairs(change_lines) do
-              table.insert(modified, start_idx + i, line)
+              table.insert(modified, start_idx + i - 1, line)
             end
           end
 
@@ -400,6 +402,10 @@ return {
         end
 
         opts.on_hide = function()
+          vim.api.nvim_win_call(vim.fn.bufwinid(diff.bufnr), function()
+            vim.cmd('diffoff')
+          end)
+
           vim.api.nvim_win_call(copilot.chat.winnr, function()
             vim.cmd('diffoff')
           end)

From 1b489a75d82f12b53fe6de08917e24c5425fefb5 Mon Sep 17 00:00:00 2001
From: Wei Meng <exdream@live.cn>
Date: Fri, 4 Jul 2025 13:44:57 +0800
Subject: [PATCH 2/2] remove extra empty line at end of file in diff mode

---
 lua/CopilotChat/ui/overlay.lua | 1 -
 1 file changed, 1 deletion(-)

diff --git a/lua/CopilotChat/ui/overlay.lua b/lua/CopilotChat/ui/overlay.lua
index 9b70cb5e..e55b867f 100644
--- a/lua/CopilotChat/ui/overlay.lua
+++ b/lua/CopilotChat/ui/overlay.lua
@@ -39,7 +39,6 @@ function Overlay:show(text, winnr, filetype, syntax, on_show, on_hide)
 
   self:validate()
   vim.api.nvim_win_set_hl_ns(winnr, self.hl_ns)
-  text = text .. '\n'
 
   self.cursor = vim.api.nvim_win_get_cursor(winnr)
   vim.api.nvim_win_set_buf(winnr, self.bufnr)