fix(lsp): filetype matching to documentSelector in dynamic capabilities (#25425)

Use the get_language_id client option to resolve the filetype when
matching the document selector in a dynamic capability.


Co-authored-by: Mathias Fussenegger <f.mathias@zignar.net>

1 files changed, 10 insertions, 6 deletions

diff --git a/runtime/lua/vim/lsp/_dynamic.lua b/runtime/lua/vim/lsp/_dynamic.lua
index 4bee58559f..5edb27b498 100644
--- a/runtime/lua/vim/lsp/_dynamic.lua
+++ b/runtime/lua/vim/lsp/_dynamic.lua
@@ -55,7 +55,7 @@ function M:unregister(unregisterations)
 end
 
 --- @param method string
---- @param opts? {bufnr?: number}
+--- @param opts? {bufnr: integer?}
 --- @return lsp.Registration? (table|nil) the registration if found
 --- @private
 function M:get(method, opts)
@@ -69,14 +69,14 @@ function M:get(method, opts)
     if not documentSelector then
       return reg
     end
-    if M.match(opts.bufnr, documentSelector) then
+    if self:match(opts.bufnr, documentSelector) then
       return reg
     end
   end
 end
 
 --- @param method string
---- @param opts? {bufnr?: number}
+--- @param opts? {bufnr: integer?}
 --- @private
 function M:supports(method, opts)
   return self:get(method, opts) ~= nil
@@ -85,13 +85,17 @@ end
 --- @param bufnr number
 --- @param documentSelector lsp.DocumentSelector
 --- @private
-function M.match(bufnr, documentSelector)
-  local ft = vim.bo[bufnr].filetype
+function M:match(bufnr, documentSelector)
+  local client = vim.lsp.get_client_by_id(self.client_id)
+  if not client then
+    return false
+  end
+  local language = client.config.get_language_id(bufnr, vim.bo[bufnr].filetype)
   local uri = vim.uri_from_bufnr(bufnr)
   local fname = vim.uri_to_fname(uri)
   for _, filter in ipairs(documentSelector) do
     local matches = true
-    if filter.language and ft ~= filter.language then
+    if filter.language and language ~= filter.language then
       matches = false
     end
     if matches and filter.scheme and not vim.startswith(uri, filter.scheme .. ':') then