refactor(lsp): resolve the config-client entanglement

Previously the LSP-Client object contained some fields that are also
in the client config, but for a lot of other fields, the config was used
directly making the two objects vaguely entangled with either not having
a clear role.

Now the config object is treated purely as config (read-only) from the
client, and any fields the client needs from the config are now copied
in as additional fields.

This means:
- the config object is no longet normalised and is left as the user
  provided it.
- the client only reads the config on creation of the client and all
  other implementations now read the clients version of the fields.

In addition, internal support for multiple callbacks has been added to
the client so the client tracking logic (done in lua.lsp) can be done
more robustly instead of wrapping the user callbacks which may error.

1 files changed, 3 insertions, 3 deletions

diff --git a/runtime/lua/vim/lsp/_changetracking.lua b/runtime/lua/vim/lsp/_changetracking.lua
index 8b624cd5ea..3ecdec1659 100644
--- a/runtime/lua/vim/lsp/_changetracking.lua
+++ b/runtime/lua/vim/lsp/_changetracking.lua
@@ -64,7 +64,7 @@ local state_by_group = setmetatable({}, {
 ---@param client lsp.Client
 ---@return vim.lsp.CTGroup
 local function get_group(client)
-  local allow_inc_sync = vim.F.if_nil(client.config.flags.allow_incremental_sync, true) --- @type boolean
+  local allow_inc_sync = vim.F.if_nil(client.flags.allow_incremental_sync, true) --- @type boolean
   local change_capability = vim.tbl_get(client.server_capabilities, 'textDocumentSync', 'change')
   local sync_kind = change_capability or protocol.TextDocumentSyncKind.None
   if not allow_inc_sync and change_capability == protocol.TextDocumentSyncKind.Incremental then
@@ -134,12 +134,12 @@ function M.init(client, bufnr)
   local group = get_group(client)
   local state = state_by_group[group]
   if state then
-    state.debounce = math.min(state.debounce, client.config.flags.debounce_text_changes or 150)
+    state.debounce = math.min(state.debounce, client.flags.debounce_text_changes or 150)
     state.clients[client.id] = client
   else
     state = {
       buffers = {},
-      debounce = client.config.flags.debounce_text_changes or 150,
+      debounce = client.flags.debounce_text_changes or 150,
       clients = {
         [client.id] = client,
       },