fix(exrc): ensure consistent 'exrc' loading sequence #35148

Problem:
The execution of startup scripts in parent directories are too late
compared to scripts in current direcctory.

Solution:
Execute all startup scripts with `lua/_core/exrc.lua`.

closes: #35147

1 files changed, 19 insertions, 0 deletions

diff --git a/runtime/lua/vim/_core/exrc.lua b/runtime/lua/vim/_core/exrc.lua
new file mode 100644
index 0000000000..2fa586933b
--- /dev/null
+++ b/runtime/lua/vim/_core/exrc.lua
@@ -0,0 +1,19 @@
+local files = vim.fs.find({ '.nvim.lua', '.nvimrc', '.exrc' }, {
+  type = 'file',
+  upward = true,
+  limit = math.huge,
+})
+for _, file in ipairs(files) do
+  local trusted = vim.secure.read(file) --[[@as string|nil]]
+  if trusted then
+    if vim.endswith(file, '.lua') then
+      assert(loadstring(trusted, '@' .. file))()
+    else
+      vim.api.nvim_exec2(trusted, {})
+    end
+  end
+  -- If the user unset 'exrc' in the current exrc then stop searching
+  if not vim.o.exrc then
+    break
+  end
+end