fix(diagnostic): improve current_line refresh logic #32275

Problem:
The current implementation uses a global augroup for virtual lines in
diagnostics, which can lead to conflicts and unintended behavior when
multiple namespaces/buffers are involved.

Solution:
Refactor the code to use a namespace-specific augroup for virtual lines.
This ensures that each namespace has its own augroup.
Scope the clear commands to only the relevant buffer.

1 files changed, 8 insertions, 7 deletions

diff --git a/runtime/lua/vim/diagnostic.lua b/runtime/lua/vim/diagnostic.lua
index 2538cd3048..6016867046 100644
--- a/runtime/lua/vim/diagnostic.lua
+++ b/runtime/lua/vim/diagnostic.lua
@@ -344,7 +344,6 @@ local global_diagnostic_options = {
 --- @class (private) vim.diagnostic.Handler
 --- @field show? fun(namespace: integer, bufnr: integer, diagnostics: vim.Diagnostic[], opts?: vim.diagnostic.OptsResolved)
 --- @field hide? fun(namespace:integer, bufnr:integer)
---- @field _augroup? integer
 
 --- @nodoc
 --- @type table<string,vim.diagnostic.Handler>
@@ -1841,12 +1840,14 @@ M.handlers.virtual_lines = {
       ns.user_data.virt_lines_ns =
         api.nvim_create_namespace(string.format('nvim.%s.diagnostic.virtual_lines', ns.name))
     end
-    if not M.handlers.virtual_lines._augroup then
-      M.handlers.virtual_lines._augroup =
-        api.nvim_create_augroup('nvim.lsp.diagnostic.virt_lines', { clear = true })
+    if not ns.user_data.virt_lines_augroup then
+      ns.user_data.virt_lines_augroup = api.nvim_create_augroup(
+        string.format('nvim.%s.diagnostic.virt_lines', ns.name),
+        { clear = true }
+      )
     end
 
-    api.nvim_clear_autocmds({ group = M.handlers.virtual_lines._augroup })
+    api.nvim_clear_autocmds({ group = ns.user_data.virt_lines_augroup, buffer = bufnr })
 
     if opts.virtual_lines.format then
       diagnostics = reformat_diagnostics(opts.virtual_lines.format, diagnostics)
@@ -1855,7 +1856,7 @@ M.handlers.virtual_lines = {
     if opts.virtual_lines.current_line == true then
       api.nvim_create_autocmd('CursorMoved', {
         buffer = bufnr,
-        group = M.handlers.virtual_lines._augroup,
+        group = ns.user_data.virt_lines_augroup,
         callback = function()
           render_virtual_lines_at_current_line(diagnostics, ns.user_data.virt_lines_ns, bufnr)
         end,
@@ -1875,7 +1876,7 @@ M.handlers.virtual_lines = {
       if api.nvim_buf_is_valid(bufnr) then
         api.nvim_buf_clear_namespace(bufnr, ns.user_data.virt_lines_ns, 0, -1)
       end
-      api.nvim_clear_autocmds({ group = M.handlers.virtual_lines._augroup })
+      api.nvim_clear_autocmds({ group = ns.user_data.virt_lines_augroup, buffer = bufnr })
     end
   end,
 }