1 files changed, 8 insertions, 21 deletions
diff --git a/runtime/lua/vim/lsp.lua b/runtime/lua/vim/lsp.lua
index 9bc6679228..f0845bfc80 100644
--- a/runtime/lua/vim/lsp.lua
+++ b/runtime/lua/vim/lsp.lua
@@ -265,8 +265,11 @@ end
 --@param bufnr (Number) Number of the buffer, or 0 for current
 --@param client Client object
 local function text_document_did_open_handler(bufnr, client)
-  local allow_incremental_sync = if_nil(client.config.flags.allow_incremental_sync, false)
-  if allow_incremental_sync then
+  local use_incremental_sync = (
+    if_nil(client.config.flags.allow_incremental_sync, true)
+    and client.resolved_capabilities.text_document_did_change == protocol.TextDocumentSyncKind.Incremental
+  )
+  if use_incremental_sync then
     if not client._cached_buffers then
       client._cached_buffers = {}
     end
@@ -452,16 +455,7 @@ end
 --@param trace:  "off" | "messages" | "verbose" | nil passed directly to the language
 --- server in the initialize request. Invalid/empty values will default to "off"
 --@param flags: A table with flags for the client. The current (experimental) flags are:
---- - allow_incremental_sync (bool, default false): Allow using on_line callbacks for lsp
----
---- <pre>
---- -- In attach function for the client, you can do:
---- local custom_attach = function(client)
----   if client.config.flags then
----     client.config.flags.allow_incremental_sync = true
----   end
---- end
---- </pre>
+--- - allow_incremental_sync (bool, default true): Allow using incremental sync for buffer edits
 ---
 --@returns Client id. |vim.lsp.get_client_by_id()| Note: client may not be
 --- fully initialized. Use `on_init` to do any actions once
@@ -858,19 +852,12 @@ do
       };
     end)
     local uri = vim.uri_from_bufnr(bufnr)
-    for_each_buffer_client(bufnr, function(client, _client_id)
-      local allow_incremental_sync = if_nil(client.config.flags.allow_incremental_sync, false)
-
+    for_each_buffer_client(bufnr, function(client)
+      local allow_incremental_sync = if_nil(client.config.flags.allow_incremental_sync, true)
       local text_document_did_change = client.resolved_capabilities.text_document_did_change
       local changes
       if text_document_did_change == protocol.TextDocumentSyncKind.None then
         return
-      --[=[ TODO(ashkan) there seem to be problems with the byte_sizes sent by
-      -- neovim right now so only send the full content for now. In general, we
-      -- can assume that servers *will* support both versions anyway, as there
-      -- is no way to specify the sync capability by the client.
-      -- See https://github.com/palantir/python-language-server/commit/cfd6675bc10d5e8dbc50fc50f90e4a37b7178821#diff-f68667852a14e9f761f6ebf07ba02fc8 for an example of pyls handling both.
-      --]=]
       elseif not allow_incremental_sync or text_document_did_change == protocol.TextDocumentSyncKind.Full then
         changes = full_changes(client)
       elseif text_document_did_change == protocol.TextDocumentSyncKind.Incremental then