From ce5e230af8d371ba78d04057d7d840bd4c31fd22 Mon Sep 17 00:00:00 2001
From: Volodymyr Chernetskyi <volodymyr_chernetskyi@goodyear.com>
Date: Mon, 7 Sep 2026 18:21:11 +0200
Subject: [PATCH] fix(lsp): show_document() reports a failed buffer load #41731

Problem:
vim.lsp.util.show_document() can fail to load the target buffer, most
visibly with E325 when another process owns the file's swapfile and the
user declines to open it. The Vim error escapes show_document() and
surfaces inside whichever LSP handler called it, instead of being
reported as a failure to show the document.

Solution:
Load the buffer up front with vim.fn.bufload(), before any of that
state is touched, and report the error instead of raising.

AI-assisted
---
 runtime/lua/vim/lsp/util.lua | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/runtime/lua/vim/lsp/util.lua b/runtime/lua/vim/lsp/util.lua
index 0da99e70bf..7a8e8d6812 100644
--- a/runtime/lua/vim/lsp/util.lua
+++ b/runtime/lua/vim/lsp/util.lua
@@ -876,6 +876,13 @@ function M.show_document(location, position_encoding, opts)
   end
   local bufnr = vim.uri_to_bufnr(uri)
 
+  -- Return early if the buffer fails to load, to avoid partial setup.
+  local loaded, err = pcall(vim.fn.bufload, bufnr)
+  if not loaded then
+    vim.notify(tostring(err), vim.log.levels.ERROR)
+    return false
+  end
+
   opts = opts or {}
   local focus = vim.nonnil(opts.focus, true)
   if focus then