fix(lsp): revert buf_versions deprecation/replacement (#29217)

* Revert "fix(lsp): account for changedtick version gap on modified reset (#29170)"

This reverts commit 2e6d295f799c27372e5c0c44727fa613c81717fd.

* Revert "refactor(lsp): replace util.buf_versions with changedtick (#28943)"

This reverts commit 5c33815448e11b514678f39cecc74e68131d4628.

10 files changed, 69 insertions, 67 deletions

diff --git a/runtime/doc/deprecated.txt b/runtime/doc/deprecated.txt
index 3b3e6afa9e..6c6585d76e 100644
--- a/runtime/doc/deprecated.txt
+++ b/runtime/doc/deprecated.txt
@@ -22,9 +22,6 @@ API
 LUA
 - vim.region()		Use |getregionpos()| instead.
 
-LSP
-- *vim.lsp.util.buf_versions*	Use |b:changedtick| instead.
-
 DIAGNOSTICS
 - *vim.diagnostic.goto_next()*	Use |vim.diagnostic.jump()| with `{count = 1}` instead.
 - *vim.diagnostic.goto_prev()*	Use |vim.diagnostic.jump()| with `{count = -1}` instead.
diff --git a/runtime/lua/vim/lsp.lua b/runtime/lua/vim/lsp.lua
index 49a24f873c..eb50a0b880 100644
--- a/runtime/lua/vim/lsp.lua
+++ b/runtime/lua/vim/lsp.lua
@@ -484,6 +484,7 @@ local function text_document_did_save_handler(bufnr)
           text = lsp._buf_get_full_text(bufnr),
         },
       })
+      util.buf_versions[bufnr] = 0
     end
     local save_capability = vim.tbl_get(client.server_capabilities, 'textDocumentSync', 'save')
     if save_capability then
@@ -519,6 +520,7 @@ local function buf_detach_client(bufnr, client)
   end
 
   client.attached_buffers[bufnr] = nil
+  util.buf_versions[bufnr] = nil
 
   local namespace = lsp.diagnostic.get_namespace(client.id)
   vim.diagnostic.reset(namespace, bufnr)
@@ -574,11 +576,12 @@ local function buf_attach(bufnr)
   })
   -- First time, so attach and set up stuff.
   api.nvim_buf_attach(bufnr, false, {
-    on_lines = function(_, _, _, firstline, lastline, new_lastline)
+    on_lines = function(_, _, changedtick, firstline, lastline, new_lastline)
       if #lsp.get_clients({ bufnr = bufnr }) == 0 then
         -- detach if there are no clients
         return #lsp.get_clients({ bufnr = bufnr, _uninitialized = true }) == 0
       end
+      util.buf_versions[bufnr] = changedtick
       changetracking.send_changes(bufnr, firstline, lastline, new_lastline)
     end,
 
diff --git a/runtime/lua/vim/lsp/_changetracking.lua b/runtime/lua/vim/lsp/_changetracking.lua
index ce701f0772..b2be53269f 100644
--- a/runtime/lua/vim/lsp/_changetracking.lua
+++ b/runtime/lua/vim/lsp/_changetracking.lua
@@ -1,5 +1,6 @@
 local protocol = require('vim.lsp.protocol')
 local sync = require('vim.lsp.sync')
+local util = require('vim.lsp.util')
 
 local api = vim.api
 local uv = vim.uv
@@ -276,7 +277,7 @@ local function send_changes(bufnr, sync_kind, state, buf_state)
       client.notify(protocol.Methods.textDocument_didChange, {
         textDocument = {
           uri = uri,
-          version = vim.b[bufnr].changedtick,
+          version = util.buf_versions[bufnr],
         },
         contentChanges = changes,
       })
diff --git a/runtime/lua/vim/lsp/client.lua b/runtime/lua/vim/lsp/client.lua
index b28fe2f797..327cd19125 100644
--- a/runtime/lua/vim/lsp/client.lua
+++ b/runtime/lua/vim/lsp/client.lua
@@ -673,8 +673,8 @@ function Client:_request(method, params, handler, bufnr)
   end
   -- Ensure pending didChange notifications are sent so that the server doesn't operate on a stale state
   changetracking.flush(self, bufnr)
+  local version = lsp.util.buf_versions[bufnr]
   bufnr = resolve_bufnr(bufnr)
-  local version = vim.b[bufnr].changedtick
   log.debug(self._log_prefix, 'client.request', self.id, method, params, handler, bufnr)
   local success, request_id = self.rpc.request(method, params, function(err, result)
     local context = {
@@ -922,13 +922,14 @@ function Client:_text_document_did_open_handler(bufnr)
 
   local params = {
     textDocument = {
-      version = vim.b[bufnr].changedtick,
+      version = 0,
       uri = vim.uri_from_bufnr(bufnr),
       languageId = self.get_language_id(bufnr, filetype),
       text = lsp._buf_get_full_text(bufnr),
     },
   }
   self.notify(ms.textDocument_didOpen, params)
+  lsp.util.buf_versions[bufnr] = params.textDocument.version
 
   -- Next chance we get, we should re-do the diagnostics
   vim.schedule(function()
diff --git a/runtime/lua/vim/lsp/inlay_hint.lua b/runtime/lua/vim/lsp/inlay_hint.lua
index 8fd4ceefd2..2d784816cb 100644
--- a/runtime/lua/vim/lsp/inlay_hint.lua
+++ b/runtime/lua/vim/lsp/inlay_hint.lua
@@ -43,7 +43,7 @@ function M.on_inlayhint(err, result, ctx, _)
     return
   end
   local bufnr = assert(ctx.bufnr)
-  if vim.b[bufnr].changedtick ~= ctx.version then
+  if util.buf_versions[bufnr] ~= ctx.version then
     return
   end
   local client_id = ctx.client_id
@@ -324,7 +324,7 @@ api.nvim_set_decoration_provider(namespace, {
       return
     end
 
-    if bufstate.version ~= vim.b[bufnr].changedtick then
+    if bufstate.version ~= util.buf_versions[bufnr] then
       return
     end
 
diff --git a/runtime/lua/vim/lsp/semantic_tokens.lua b/runtime/lua/vim/lsp/semantic_tokens.lua
index b2a8360aa2..279956658c 100644
--- a/runtime/lua/vim/lsp/semantic_tokens.lua
+++ b/runtime/lua/vim/lsp/semantic_tokens.lua
@@ -116,7 +116,7 @@ local function tokens_to_ranges(data, bufnr, client, request)
 
       if elapsed_ns > yield_interval_ns then
         vim.schedule(function()
-          coroutine.resume(co, vim.b[bufnr].changedtick)
+          coroutine.resume(co, util.buf_versions[bufnr])
         end)
         if request.version ~= coroutine.yield() then
           -- request became stale since the last time the coroutine ran.
@@ -269,7 +269,7 @@ end
 ---
 ---@package
 function STHighlighter:send_request()
-  local version = vim.b[self.bufnr].changedtick
+  local version = util.buf_versions[self.bufnr]
 
   self:reset_timer()
 
@@ -412,7 +412,7 @@ end
 function STHighlighter:on_win(topline, botline)
   for client_id, state in pairs(self.client_state) do
     local current_result = state.current_result
-    if current_result.version and current_result.version == vim.b[self.bufnr].changedtick then
+    if current_result.version and current_result.version == util.buf_versions[self.bufnr] then
       if not current_result.namespace_cleared then
         api.nvim_buf_clear_namespace(self.bufnr, state.namespace, 0, -1)
         current_result.namespace_cleared = true
diff --git a/runtime/lua/vim/lsp/util.lua b/runtime/lua/vim/lsp/util.lua
index 3215b40d1d..fc027cfcc0 100644
--- a/runtime/lua/vim/lsp/util.lua
+++ b/runtime/lua/vim/lsp/util.lua
@@ -502,11 +502,6 @@ function M.apply_text_document_edit(text_document_edit, index, offset_encoding)
     should_check_version = false
   end
 
-  -- changedtick increases on save but server only receives version updates
-  -- on line changes (via didChange)
-  -- This allows a gap of 1 to account for the servers outdated view
-  local version_offset = vim.b[bufnr].modified and 0 or 1
-
   -- `VersionedTextDocumentIdentifier`s version may be null
   --  https://microsoft.github.io/language-server-protocol/specification#versionedTextDocumentIdentifier
   if
@@ -514,7 +509,8 @@ function M.apply_text_document_edit(text_document_edit, index, offset_encoding)
     and (
       text_document.version
       and text_document.version > 0
-      and vim.b[bufnr].changedtick > (text_document.version + version_offset)
+      and M.buf_versions[bufnr]
+      and M.buf_versions[bufnr] > text_document.version
     )
   then
     print('Buffer ', text_document.uri, ' newer than edits.')
@@ -2206,16 +2202,9 @@ function M._refresh(method, opts)
   end
 end
 
----@nodoc
----@deprecated
----@type table<integer,integer>
-M.buf_versions = setmetatable({}, {
-  __index = function(_, bufnr)
-    vim.deprecate('vim.lsp.util.buf_versions', 'vim.b.changedtick', '0.13')
-    return vim.b[bufnr].changedtick
-  end,
-})
-
 M._get_line_byte_from_position = get_line_byte_from_position
 
+---@nodoc
+M.buf_versions = {} ---@type table<integer,integer>
+
 return M
diff --git a/test/functional/fixtures/fake-lsp-server.lua b/test/functional/fixtures/fake-lsp-server.lua
index 9aafd38d4f..f806869b40 100644
--- a/test/functional/fixtures/fake-lsp-server.lua
+++ b/test/functional/fixtures/fake-lsp-server.lua
@@ -471,7 +471,7 @@ function tests.basic_check_buffer_open()
           languageId = '',
           text = table.concat({ 'testing', '123' }, '\n') .. '\n',
           uri = 'file://',
-          version = 2,
+          version = 0,
         },
       })
       expect_notification('finish')
@@ -498,7 +498,7 @@ function tests.basic_check_buffer_open_and_change()
           languageId = '',
           text = table.concat({ 'testing', '123' }, '\n') .. '\n',
           uri = 'file://',
-          version = 2,
+          version = 0,
         },
       })
       expect_notification('textDocument/didChange', {
@@ -534,7 +534,7 @@ function tests.basic_check_buffer_open_and_change_noeol()
           languageId = '',
           text = table.concat({ 'testing', '123' }, '\n'),
           uri = 'file://',
-          version = 2,
+          version = 0,
         },
       })
       expect_notification('textDocument/didChange', {
@@ -569,7 +569,7 @@ function tests.basic_check_buffer_open_and_change_multi()
           languageId = '',
           text = table.concat({ 'testing', '123' }, '\n') .. '\n',
           uri = 'file://',
-          version = 2,
+          version = 0,
         },
       })
       expect_notification('textDocument/didChange', {
@@ -614,7 +614,7 @@ function tests.basic_check_buffer_open_and_change_multi_and_close()
           languageId = '',
           text = table.concat({ 'testing', '123' }, '\n') .. '\n',
           uri = 'file://',
-          version = 2,
+          version = 0,
         },
       })
       expect_notification('textDocument/didChange', {
@@ -672,7 +672,7 @@ function tests.basic_check_buffer_open_and_change_incremental()
           languageId = '',
           text = table.concat({ 'testing', '123' }, '\n') .. '\n',
           uri = 'file://',
-          version = 2,
+          version = 0,
         },
       })
       expect_notification('textDocument/didChange', {
@@ -715,7 +715,7 @@ function tests.basic_check_buffer_open_and_change_incremental_editing()
           languageId = '',
           text = table.concat({ 'testing', '123' }, '\n'),
           uri = 'file://',
-          version = 2,
+          version = 0,
         },
       })
       expect_notification('textDocument/didChange', {
diff --git a/test/functional/plugin/lsp/semantic_tokens_spec.lua b/test/functional/plugin/lsp/semantic_tokens_spec.lua
index 9babb080e7..7908c5d2e7 100644
--- a/test/functional/plugin/lsp/semantic_tokens_spec.lua
+++ b/test/functional/plugin/lsp/semantic_tokens_spec.lua
@@ -111,7 +111,6 @@ describe('semantic token highlighting', function()
     end)
 
     it('buffer is highlighted when attached', function()
-      insert(text)
       exec_lua([[
         bufnr = vim.api.nvim_get_current_buf()
         vim.api.nvim_win_set_buf(0, bufnr)
@@ -119,6 +118,8 @@ describe('semantic token highlighting', function()
         client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
       ]])
 
+      insert(text)
+
       screen:expect {
         grid = [[
         #include <iostream>                     |
@@ -140,7 +141,6 @@ describe('semantic token highlighting', function()
     end)
 
     it('use LspTokenUpdate and highlight_token', function()
-      insert(text)
       exec_lua([[
         vim.api.nvim_create_autocmd("LspTokenUpdate", {
           callback = function(args)
@@ -157,6 +157,8 @@ describe('semantic token highlighting', function()
         client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
       ]])
 
+      insert(text)
+
       screen:expect {
         grid = [[
         #include <iostream>                     |
@@ -178,17 +180,14 @@ describe('semantic token highlighting', function()
     end)
 
     it('buffer is unhighlighted when client is detached', function()
-      insert(text)
-
       exec_lua([[
         bufnr = vim.api.nvim_get_current_buf()
         vim.api.nvim_win_set_buf(0, bufnr)
         client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
-        vim.wait(1000, function()
-          return #server.messages > 1
-        end)
       ]])
 
+      insert(text)
+
       exec_lua([[
         vim.notify = function() end
         vim.lsp.buf_detach_client(bufnr, client_id)
@@ -332,13 +331,14 @@ describe('semantic token highlighting', function()
     end)
 
     it('buffer is re-highlighted when force refreshed', function()
-      insert(text)
       exec_lua([[
         bufnr = vim.api.nvim_get_current_buf()
         vim.api.nvim_win_set_buf(0, bufnr)
         client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
       ]])
 
+      insert(text)
+
       screen:expect {
         grid = [[
         #include <iostream>                     |
@@ -412,14 +412,13 @@ describe('semantic token highlighting', function()
     end)
 
     it('updates highlights with delta request on buffer change', function()
-      insert(text)
-
       exec_lua([[
         bufnr = vim.api.nvim_get_current_buf()
         vim.api.nvim_win_set_buf(0, bufnr)
         client_id = vim.lsp.start({ name = 'dummy', cmd = server.cmd })
       ]])
 
+      insert(text)
       screen:expect {
         grid = [[
         #include <iostream>                     |
@@ -598,7 +597,6 @@ describe('semantic token highlighting', function()
     end)
 
     it('does not send delta requests if not supported by server', function()
-      insert(text)
       exec_lua(
         [[
         local legend, response, edit_response = ...
@@ -627,6 +625,7 @@ describe('semantic token highlighting', function()
         edit_response
       )
 
+      insert(text)
       screen:expect {
         grid = [[
         #include <iostream>                     |
@@ -1450,7 +1449,6 @@ int main()
       },
     }) do
       it(test.it, function()
-        insert(test.text1)
         exec_lua(create_server_definition)
         exec_lua(
           [[
@@ -1487,6 +1485,8 @@ int main()
           test.response2
         )
 
+        insert(test.text1)
+
         test.expected_screen1()
 
         local highlights = exec_lua([[
diff --git a/test/functional/plugin/lsp_spec.lua b/test/functional/plugin/lsp_spec.lua
index 23f6b733d5..0cf84b50c2 100644
--- a/test/functional/plugin/lsp_spec.lua
+++ b/test/functional/plugin/lsp_spec.lua
@@ -255,7 +255,7 @@ describe('LSP', function()
         return
       end
       local expected_handlers = {
-        { NIL, {}, { method = 'shutdown', bufnr = 1, client_id = 1, version = 2 } },
+        { NIL, {}, { method = 'shutdown', bufnr = 1, client_id = 1 } },
         { NIL, {}, { method = 'test', client_id = 1 } },
       }
       test_rpc_server {
@@ -948,11 +948,7 @@ describe('LSP', function()
     it('should forward ContentModified to callback', function()
       local expected_handlers = {
         { NIL, {}, { method = 'finish', client_id = 1 } },
-        {
-          { code = -32801 },
-          NIL,
-          { method = 'error_code_test', bufnr = 1, client_id = 1, version = 2 },
-        },
+        { { code = -32801 }, NIL, { method = 'error_code_test', bufnr = 1, client_id = 1 } },
       }
       local client --- @type vim.lsp.Client
       test_rpc_server {
@@ -982,7 +978,7 @@ describe('LSP', function()
     it('should track pending requests to the language server', function()
       local expected_handlers = {
         { NIL, {}, { method = 'finish', client_id = 1 } },
-        { NIL, {}, { method = 'slow_request', bufnr = 1, client_id = 1, version = 2 } },
+        { NIL, {}, { method = 'slow_request', bufnr = 1, client_id = 1 } },
       }
       local client --- @type vim.lsp.Client
       test_rpc_server {
@@ -1049,7 +1045,7 @@ describe('LSP', function()
     it('should clear pending and cancel requests on reply', function()
       local expected_handlers = {
         { NIL, {}, { method = 'finish', client_id = 1 } },
-        { NIL, {}, { method = 'slow_request', bufnr = 1, client_id = 1, version = 2 } },
+        { NIL, {}, { method = 'slow_request', bufnr = 1, client_id = 1 } },
       }
       local client --- @type vim.lsp.Client
       test_rpc_server {
@@ -1088,7 +1084,7 @@ describe('LSP', function()
     it('should trigger LspRequest autocmd when requests table changes', function()
       local expected_handlers = {
         { NIL, {}, { method = 'finish', client_id = 1 } },
-        { NIL, {}, { method = 'slow_request', bufnr = 1, client_id = 1, version = 2 } },
+        { NIL, {}, { method = 'slow_request', bufnr = 1, client_id = 1 } },
       }
       local client --- @type vim.lsp.Client
       test_rpc_server {
@@ -1368,7 +1364,6 @@ describe('LSP', function()
             },
             bufnr = 2,
             client_id = 1,
-            version = 2,
           },
         },
         { NIL, {}, { method = 'start', client_id = 1 } },
@@ -2122,6 +2117,7 @@ describe('LSP', function()
         local args = {...}
         local bufnr = select(1, ...)
         local text_edit = select(2, ...)
+        vim.lsp.util.buf_versions[bufnr] = 10
         vim.lsp.util.apply_text_document_edit(text_edit, nil, 'utf-16')
       ]],
         target_bufnr,
@@ -2133,13 +2129,16 @@ describe('LSP', function()
       }, buf_lines(target_bufnr))
     end)
     it('skips the edit if the version of the edit is behind the local buffer ', function()
-      local apply_edit_mocking_current_version = function(edit)
+      local apply_edit_mocking_current_version = function(edit, versionedBuf)
         exec_lua(
           [[
           local args = {...}
+          local versionedBuf = args[2]
+          vim.lsp.util.buf_versions[versionedBuf.bufnr] = versionedBuf.currentVersion
           vim.lsp.util.apply_text_document_edit(args[1], nil, 'utf-16')
         ]],
-          edit
+          edit,
+          versionedBuf
         )
       end
 
@@ -2151,17 +2150,17 @@ describe('LSP', function()
       eq(baseText, buf_lines(target_bufnr))
 
       -- Apply an edit for an old version, should skip
-      apply_edit_mocking_current_version(text_document_edit(1))
+      apply_edit_mocking_current_version(
+        text_document_edit(2),
+        { currentVersion = 7, bufnr = target_bufnr }
+      )
       eq(baseText, buf_lines(target_bufnr)) -- no change
 
       -- Sanity check that next version to current does apply change
-      apply_edit_mocking_current_version(text_document_edit(exec_lua(
-        [[
-          local bufnr = ...
-          return vim.b[bufnr].changedtick
-        ]],
-        target_bufnr
-      )))
+      apply_edit_mocking_current_version(
+        text_document_edit(8),
+        { currentVersion = 7, bufnr = target_bufnr }
+      )
       eq({
         'First ↥ 🤦 🦄 line of text',
         '2nd line of 语text',
@@ -2240,6 +2239,18 @@ describe('LSP', function()
         }
 
         vim.api.nvim_buf_set_lines(bufnr, 0, -1, false, lines)
+
+        local update_changed_tick = function()
+          vim.lsp.util.buf_versions[bufnr] = vim.api.nvim_buf_get_var(bufnr, 'changedtick')
+        end
+
+        update_changed_tick()
+        vim.api.nvim_buf_attach(bufnr, false, {
+          on_changedtick = function()
+            update_changed_tick()
+          end
+        })
+
         return {bufnr, vim.api.nvim_buf_get_var(bufnr, 'changedtick')}
       ]]