diff --git a/.github/scripts/labeler_configuration.yml b/.github/scripts/labeler_configuration.yml
index 933e0bcbbd..b548d96afc 100644
--- a/.github/scripts/labeler_configuration.yml
+++ b/.github/scripts/labeler_configuration.yml
@@ -46,6 +46,10 @@ folds:
   - changed-files:
     - any-glob-to-any-file: [ src/nvim/fold* ]
 
+image:
+  - changed-files:
+    - any-glob-to-any-file: [ '**/ui/img*' ]
+
 lsp:
   - changed-files:
     - any-glob-to-any-file: [ runtime/lua/vim/lsp.lua, runtime/lua/vim/lsp/* ]
diff --git a/.github/workflows/labeler_issue.yml b/.github/workflows/labeler_issue.yml
index e448c604e9..f145a9894a 100644
--- a/.github/workflows/labeler_issue.yml
+++ b/.github/workflows/labeler_issue.yml
@@ -17,7 +17,14 @@ jobs:
           script: |
             const title = context.payload.issue.title;
             const titleSplit = title.split(/\b/).map(e => e.toLowerCase());
-            const keywords = ['api', 'lsp', 'treesitter', 'ui', 'ui2'];
+            const keywords = [
+              'api',
+              'image',
+              'lsp',
+              'treesitter',
+              'ui',
+              'ui2'
+            ];
             var labels = new Set();
 
             for (const keyword of keywords) {
diff --git a/runtime/doc/api.txt b/runtime/doc/api.txt
index 8c8aceea4b..5c171cff57 100644
--- a/runtime/doc/api.txt
+++ b/runtime/doc/api.txt
@@ -154,7 +154,7 @@ indices, end-inclusive):
 - |nvim_buf_get_extmarks()|
 - |nvim_buf_set_extmark()|
 
-                                                        *api-fast* *schedule*
+						*api-fast* *deferred* *schedule*
 Most API functions are deferred: they are queued ("scheduled") on the main
 loop and processed sequentially with normal input. If the editor is waiting
 for user input in a "modal" fashion (e.g. an |input()| prompt), a deferred
diff --git a/runtime/doc/autocmd.txt b/runtime/doc/autocmd.txt
index fc1e8a3fb7..4c9f02de89 100644
--- a/runtime/doc/autocmd.txt
+++ b/runtime/doc/autocmd.txt
@@ -922,9 +922,8 @@ OptionSet			After setting an option (except during
 				always use |:noautocmd| to prevent triggering
 				OptionSet.
 
-				Note: The 'modified' option triggers
-				|OptionSet| deferred to the next event-loop
-				tick, even when set via |:set|.
+				Note: OptionSet is |deferred| when triggered by
+				'modified', even when set via |:set|.
 
 				Non-recursive: |:set| in the autocommand does
 				not trigger OptionSet again.
diff --git a/runtime/doc/dev_vimpatch.txt b/runtime/doc/dev_vimpatch.txt
index f6b7cffe69..e696416758 100644
--- a/runtime/doc/dev_vimpatch.txt
+++ b/runtime/doc/dev_vimpatch.txt
@@ -6,15 +6,13 @@ Merging patches from Vim                                    *dev-vimpatch*
 
 
 Nvim was forked from Vim 7.4.160; it is kept up-to-date with relevant Vim
-patches in order to avoid duplicate work. Run `vim-patch.sh`
-https://github.com/neovim/neovim/blob/master/scripts/vim-patch.sh to see the
-status of Vim patches:
->bash
+patches in order to avoid duplicate work. Run `vim-patch.sh` to see the status
+of Vim patches: >bash
     ./scripts/vim-patch.sh -l
 <
-Everyone is welcome to |dev-vimpatch-pull-requests| for relevant Vim
-patches, but some types of patches are |dev-vimpatch-not-applicable|.
-See |dev-vimpatch-quickstart| to get started immediately.
+Everyone is welcome to |dev-vimpatch-pull-requests| for relevant Vim patches,
+but some types of patches are |dev-vimpatch-not-applicable|. See
+|dev-vimpatch-quickstart| to get started immediately.
 
 
                                          Type |gO| to see the table of contents.
diff --git a/runtime/doc/gui.txt b/runtime/doc/gui.txt
index 2453fe605f..b21f072e33 100644
--- a/runtime/doc/gui.txt
+++ b/runtime/doc/gui.txt
@@ -47,6 +47,15 @@ can connect to any Nvim instance).
 Example: this sets "g:gui" to the value of the UI's "rgb" field:    >
         :autocmd UIEnter * let g:gui = filter(nvim_list_uis(),{k,v-> v.chan==v:event.chan})[0].rgb
 <
+								*ui-lifecycle*
+Nvim's |clientserver| architecture allows you to |:restart|, |:detach| (Nvim
+continues in the background), or |:connect| to another instance.
+
+Use cases:
+- keep the session running on remote machines after (unexpected) SSH disconnect
+- open files in an existing session from your OS file explorer
+- run Nvim as a background process (daemon/service), atttach/detach as needed
+
 ------------------------------------------------------------------------------
 Stop or detach the current UI
 
diff --git a/runtime/doc/news.txt b/runtime/doc/news.txt
index 8f48305cb5..2cf17325ca 100644
--- a/runtime/doc/news.txt
+++ b/runtime/doc/news.txt
@@ -85,7 +85,6 @@ EVENTS
 
 • |BufModifiedSet| has been removed. Use the |OptionSet| event with pattern
   "modified" instead.
-• todo
 
 LSP
 
@@ -93,7 +92,7 @@ LSP
 
 LUA
 
-• Added `__eq` metamethod to |vim.VersionRange|.
+• todo
 
 OPTIONS
 
@@ -225,7 +224,7 @@ UI
 VIMSCRIPT
 
 • |v:exitreason| is set before |QuitPre|.
-• |v:starttime| is the process start time (nanoseconds from UNIX epoch).
+• |v:starttime| is the process start time (nanoseconds since UNIX epoch).
 
 ==============================================================================
 CHANGED FEATURES                                                 *news-changed*
diff --git a/runtime/doc/vim_diff.txt b/runtime/doc/vim_diff.txt
index 41ce83bd6a..e104336bca 100644
--- a/runtime/doc/vim_diff.txt
+++ b/runtime/doc/vim_diff.txt
@@ -334,8 +334,8 @@ Editor:
 
 Events (autocommands):
 - Fixed inconsistent behavior in execution of nested autocommands #23368
-- |OptionSet| is now fired for 'modified' when writing a file,
-  undoing changes, or using |:set| modified.
+- |OptionSet| is triggered for 'modified' when writing a file, undoing changes,
+  or using |:set| modified.
 - |Progress|
 - |RecordingEnter|
 - |RecordingLeave|
diff --git a/runtime/doc/vvars.txt b/runtime/doc/vvars.txt
index 5d7efac2c8..e61bc78624 100644
--- a/runtime/doc/vvars.txt
+++ b/runtime/doc/vvars.txt
@@ -635,7 +635,7 @@ v:stacktrace
 
 				*v:starttime* *starttime-variable*
 v:starttime
-		Timestamp (nanoseconds from UNIX epoch) when the Nvim process
+		Timestamp (nanoseconds since UNIX epoch) when the Nvim process
 		started.
 
 		To see the current "uptime": >lua
diff --git a/runtime/lua/vim/_meta/vvars.gen.lua b/runtime/lua/vim/_meta/vvars.gen.lua
index bee771bc23..543d4169c1 100644
--- a/runtime/lua/vim/_meta/vvars.gen.lua
+++ b/runtime/lua/vim/_meta/vvars.gen.lua
@@ -667,7 +667,7 @@ vim.v.shell_error = ...
 --- @type table[]
 vim.v.stacktrace = ...
 
---- Timestamp (nanoseconds from UNIX epoch) when the Nvim process
+--- Timestamp (nanoseconds since UNIX epoch) when the Nvim process
 --- started.
 ---
 --- To see the current "uptime":
diff --git a/runtime/lua/vim/lsp/inline_completion.lua b/runtime/lua/vim/lsp/inline_completion.lua
index 5bf4ba920e..e759562747 100644
--- a/runtime/lua/vim/lsp/inline_completion.lua
+++ b/runtime/lua/vim/lsp/inline_completion.lua
@@ -73,21 +73,21 @@ setmetatable(Completor, Capability)
 Capability.all[Completor.name] = Completor
 
 ---@package
----@param bufnr integer
+---@param buf integer
 ---@return vim.lsp.inline_completion.Completor
-function Completor:new(bufnr)
-  self = Capability.new(self, bufnr)
+function Completor:new(buf)
+  self = Capability.new(self, buf)
   self.client_state = {}
   api.nvim_create_autocmd({ 'InsertEnter', 'CursorMovedI', 'TextChangedP' }, {
     group = self.augroup,
-    buf = bufnr,
+    buf = buf,
     callback = function()
       self:automatic_request()
     end,
   })
   api.nvim_create_autocmd({ 'InsertLeave' }, {
     group = self.augroup,
-    buf = bufnr,
+    buf = buf,
     callback = function()
       self:abort()
     end,
diff --git a/runtime/lua/vim/lsp/linked_editing_range.lua b/runtime/lua/vim/lsp/linked_editing_range.lua
index 07cc6fb740..1a542ddade 100644
--- a/runtime/lua/vim/lsp/linked_editing_range.lua
+++ b/runtime/lua/vim/lsp/linked_editing_range.lua
@@ -191,43 +191,42 @@ end
 ---Construct a new LinkedEditor for the buffer.
 ---
 ---@private
----@param bufnr integer
+---@param buf integer
 ---@return vim.lsp.linked_editing_range.LinkedEditor
-function LinkedEditor.new(bufnr)
+function LinkedEditor.new(buf)
   local self = setmetatable({}, { __index = LinkedEditor })
 
-  self.bufnr = bufnr
-  local augroup =
-    api.nvim_create_augroup('nvim.lsp.linked_editing_range:' .. bufnr, { clear = true })
+  self.bufnr = buf
+  local augroup = api.nvim_create_augroup('nvim.lsp.linked_editing_range:' .. buf, { clear = true })
   self.augroup = augroup
   self.client_states = {}
 
   api.nvim_create_autocmd({ 'TextChanged', 'TextChangedI' }, {
-    buf = bufnr,
+    buf = buf,
     group = augroup,
     callback = function()
       for _, client_state in pairs(self.client_states) do
-        update_ranges(bufnr, client_state)
+        update_ranges(buf, client_state)
       end
       self:refresh()
     end,
   })
   api.nvim_create_autocmd('CursorMoved', {
     group = augroup,
-    buf = bufnr,
+    buf = buf,
     callback = function()
       self:refresh()
     end,
   })
   api.nvim_create_autocmd('LspDetach', {
     group = augroup,
-    buf = bufnr,
+    buf = buf,
     callback = function(ev)
       self:detach(ev.data.client_id)
     end,
   })
 
-  LinkedEditor.active[bufnr] = self
+  LinkedEditor.active[buf] = self
   return self
 end
 
diff --git a/runtime/lua/vim/lsp/rpc.lua b/runtime/lua/vim/lsp/rpc.lua
index 6739073cd3..49d125826b 100644
--- a/runtime/lua/vim/lsp/rpc.lua
+++ b/runtime/lua/vim/lsp/rpc.lua
@@ -191,7 +191,7 @@ local default_dispatchers = {
 }
 
 --- @async
-local function parse_content_length()
+local function message_decoder()
   local strbuf = strbuffer.new()
   while true do
     local header_len ---@type integer?
@@ -226,7 +226,7 @@ end
 function M.create_read_loop(handle_body, on_exit, on_error)
   on_exit = on_exit or function() end
   on_error = on_error or function() end
-  local co = coroutine.create(parse_content_length)
+  local co = coroutine.create(message_decoder)
   coroutine.resume(co)
   return function(err, chunk)
     if err then
diff --git a/runtime/lua/vim/lsp/util.lua b/runtime/lua/vim/lsp/util.lua
index 30f89ac129..7a9ebf85b0 100644
--- a/runtime/lua/vim/lsp/util.lua
+++ b/runtime/lua/vim/lsp/util.lua
@@ -923,8 +923,8 @@ function M.make_floating_popup_options(width, height, opts)
 
   local anchor = ''
 
-  local lines_above --- @type integer
-  local lines_below --- @type integer
+  local lines_above = vim.fn.winline() - 1
+  local lines_below = vim.fn.winheight(0) - lines_above
   if opts.relative == 'mouse' then
     lines_above = vim.fn.getmousepos().line - 1
     lines_below = vim.fn.winheight(0) - lines_above
@@ -932,9 +932,6 @@ function M.make_floating_popup_options(width, height, opts)
     -- No cursor to anchor against; treat the whole editor as space below.
     lines_above = 0
     lines_below = vim.o.lines
-  else
-    lines_above = vim.fn.winline() - 1
-    lines_below = vim.fn.winheight(0) - lines_above
   end
 
   local anchor_bias = opts.anchor_bias or 'auto'
@@ -962,13 +959,11 @@ function M.make_floating_popup_options(width, height, opts)
     row = 0
   end
 
-  local wincol --- @type integer
+  local wincol = vim.fn.wincol()
   if opts.relative == 'mouse' then
     wincol = vim.fn.getmousepos().column
   elseif opts.relative == 'editor' then
     wincol = 0
-  else
-    wincol = vim.fn.wincol()
   end
 
   if wincol + width + (opts.offset_x or 0) <= vim.o.columns then
diff --git a/src/gen/lint.lua b/src/gen/lint.lua
index ee7a61456f..442e5c2b9a 100644
--- a/src/gen/lint.lua
+++ b/src/gen/lint.lua
@@ -6,6 +6,7 @@ local M = {}
 --- Apply to parameter names, keyset keys, and function name parts.
 local banned_nouns = {
   buffer = 'buf',
+  bufnr = 'buf',
   -- channel = 'chan',
   command = 'cmd',
   directory = 'dir',
@@ -13,6 +14,7 @@ local banned_nouns = {
   position = 'pos',
   process = 'proc',
   window = 'win',
+  winnr = 'win',
 }
 
 --- Banned verbs. See `:help dev-name-common`.
@@ -55,31 +57,140 @@ local legacy_names = {
     nvim_list_uis = true,
     nvim_list_wins = true,
   },
+  ['runtime/lua/vim/diagnostic.lua'] = {
+    count = true,
+    get = true,
+    hide = true,
+    reset = true,
+    set = true,
+    show = true,
+    status = true,
+  },
+  ['runtime/lua/editorconfig.lua'] = {
+    config = true,
+  },
+  ['runtime/lua/vim/uri.lua'] = {
+    uri_from_bufnr = true,
+    uri_to_bufnr = true,
+  },
+  ['runtime/lua/vim/snippet.lua'] = {
+    new = true,
+  },
+  ['runtime/lua/vim/hl.lua'] = {
+    range = true,
+  },
+  ['runtime/lua/vim/filetype.lua'] = {
+    _getline = true,
+    _getlines = true,
+    _nextnonblank = true,
+  },
+  ['runtime/lua/vim/_meta/regex.lua'] = {
+    match_line = true,
+  },
+  ['runtime/lua/vim/_inspector.lua'] = {
+    ['vim.inspect_pos'] = true,
+    ['vim.show_pos'] = true,
+  },
   ['runtime/lua/vim/_core/shared.lua'] = {
     _ensure_list = true,
     _list_insert = true,
     _list_remove = true,
+    _resolve_bufnr = true,
     list_contains = true,
     tbl_contains = true,
   },
   ['runtime/lua/vim/lsp.lua'] = {
+    _buf_get_full_text = true,
+    _buf_get_line_ending = true,
+    _set_defaults = true,
+    buf_attach_client = true,
+    buf_detach_client = true,
+    buf_is_attached = true,
     buf_notify = true,
+    buf_request = true,
+    buf_request_all = true,
+    buf_request_sync = true,
+  },
+  ['runtime/lua/vim/lsp/_folding_range.lua'] = {
+    new = true,
+  },
+  ['runtime/lua/vim/lsp/_changetracking.lua'] = {
+    _send_did_save = true,
+    flush = true,
+    init = true,
+    reset_buf = true,
+    send_changes = true,
+  },
+  ['runtime/lua/vim/lsp/_capability.lua'] = {
+    new = true,
+  },
+  ['runtime/lua/vim/lsp/semantic_tokens.lua'] = {
+    _start = true,
+    force_refresh = true,
+    get_at_pos = true,
+    highlight_token = true,
+    new = true,
+  },
+  ['runtime/lua/vim/lsp/document_color.lua'] = {
+    new = true,
+  },
+  ['runtime/lua/vim/lsp/diagnostic.lua'] = {
+    _enable = true,
+    _refresh = true,
+    get_line_diagnostics = true,
+  },
+  ['runtime/lua/vim/lsp/completion.lua'] = {
+    enable = true,
+    request = true,
+  },
+  ['runtime/lua/vim/lsp/codelens.lua'] = {
+    new = true,
   },
   ['runtime/lua/vim/lsp/client.lua'] = {
+    _get_registrations = true,
+    _on_detach = true,
     _on_exit = true,
     _process_request = true,
     _process_static_registrations = true,
     _remove_workspace_folder = true,
+    _text_document_did_open_handler = true,
+    on_attach = true,
+    request = true,
+    request_sync = true,
+    supports_method = true,
   },
   ['runtime/lua/vim/lsp/util.lua'] = {
+    _make_line_range_params = true,
+    apply_text_edits = true,
+    buf_clear_references = true,
     buf_highlight_references = true,
+    get_effective_tabstop = true,
+    make_given_range_params = true,
     make_position_params = true,
+    make_text_document_params = true,
+    symbols_to_items = true,
   },
   ['runtime/lua/vim/lsp/rpc.lua'] = {
     _notify = true,
   },
   ['runtime/lua/vim/treesitter.lua'] = {
+    _create_parser = true,
+    get_captures_at_cursor = true,
+    get_captures_at_pos = true,
+    get_parser = true,
     node_contains = true,
+    start = true,
+    stop = true,
+  },
+  ['runtime/lua/vim/treesitter/languagetree.lua'] = {
+    _on_bytes = true,
+  },
+  ['runtime/lua/vim/treesitter/dev.lua'] = {
+    draw = true,
+    new = true,
+  },
+  ['runtime/lua/vim/treesitter/_fold.lua'] = {
+    new = true,
   },
   ['runtime/lua/vim/treesitter/highlighter.lua'] = {
     for_each_highlight_state = true,
@@ -105,10 +216,33 @@ local legacy_names = {
 ---
 --- @type table<string, table<string, true>>
 local legacy_fields = {
+  ['vim.Diagnostic'] = {
+    bufnr = true,
+  },
+  ['vim.lsp.Capability'] = {
+    bufnr = true,
+  },
+  ['vim.lsp.inlay_hint.enable.Filter'] = {
+    bufnr = true,
+  },
+  ['vim.lsp.inlay_hint.get.Filter'] = {
+    bufnr = true,
+  },
+  ['vim.lsp.inlay_hint.get.ret'] = {
+    bufnr = true,
+  },
+  ['TS.Heading'] = {
+    bufnr = true,
+  },
+  ['vim.treesitter.get_node.Opts'] = {
+    bufnr = true,
+  },
   ['vim.treesitter.dev.inspect_tree.Opts'] = {
+    bufnr = true,
     command = true,
   },
   ['vim.undotree.opts'] = {
+    bufnr = true,
     command = true,
   },
 }
@@ -148,12 +282,14 @@ function M.lint_names(source, api_funs, keysets, classes)
     local src_legacy = legacy_names[source] or {}
     for _, fun in ipairs(api_funs) do
       if fun.name and fun.params and not fun.deprecated and not fun.deprecated_since then
-        -- Positional parameter names: always checked (no "legacy" allowed).
-        for _, p in ipairs(fun.params) do
-          local want_name = banned_nouns[p.name]
-          if want_name then
-            local msg = '%s: %s(): param "%s" should be renamed to "%s"'
-            errors[#errors + 1] = fmt(msg, source, fun.name, p.name, want_name)
+        -- Positional parameter names.
+        if not src_legacy[fun.name] then
+          for _, p in ipairs(fun.params) do
+            local want_name = banned_nouns[p.name]
+            if want_name then
+              local msg = '%s: %s(): param "%s" should be renamed to "%s"'
+              errors[#errors + 1] = fmt(msg, source, fun.name, p.name, want_name)
+            end
           end
         end
 
diff --git a/src/nvim/option.c b/src/nvim/option.c
index 76355c783b..23907085a2 100644
--- a/src/nvim/option.c
+++ b/src/nvim/option.c
@@ -2060,7 +2060,7 @@ void set_option_sctx(OptIndex opt_idx, int opt_flags, sctx_T script_ctx)
   }
 }
 
-/// Fire OptionSet autocmd directly (called from deferred context, bypasses defer logic).
+/// Execute OptionSet autocmd now (not deferred).
 void apply_optionset_autocmd_now(OptIndex opt_idx, int opt_flags, OptVal oldval, OptVal oldval_g,
                                  OptVal oldval_l, OptVal newval, const char *errmsg)
 {
diff --git a/src/nvim/vvars.lua b/src/nvim/vvars.lua
index 7096349125..db87bcda28 100644
--- a/src/nvim/vvars.lua
+++ b/src/nvim/vvars.lua
@@ -756,7 +756,7 @@ M.vars = {
   starttime = {
     type = 'integer',
     desc = [=[
-      Timestamp (nanoseconds from UNIX epoch) when the Nvim process
+      Timestamp (nanoseconds since UNIX epoch) when the Nvim process
       started.
 
       To see the current "uptime": >lua
diff --git a/test/functional/autocmd/autocmd_spec.lua b/test/functional/autocmd/autocmd_spec.lua
index fde6440d50..487352ce7a 100644
--- a/test/functional/autocmd/autocmd_spec.lua
+++ b/test/functional/autocmd/autocmd_spec.lua
@@ -857,52 +857,4 @@ describe('autocmd', function()
       fn.execute('autocmd User ,,,there,is,,a,fly,,')
     )
   end)
-
-  describe('OptionSet modified', function()
-    before_each(clear)
-
-    it('is triggered when modified and un-modified', function()
-      source([[
-      let g:modified = 0
-      autocmd OptionSet modified let g:modified += 1
-      ]])
-      request('nvim_command', [[normal! aa\<Esc>]])
-      eq(1, eval('g:modified'))
-      request('nvim_command', [[normal! u]])
-      eq(2, eval('g:modified'))
-    end)
-
-    it('triggers when writes non-current buffer #32817', function()
-      source([[
-      let g:modified = 0
-      let g:second_trigger_buf = 0
-      autocmd OptionSet modified let g:modified += 1 | if g:modified == 2 | let g:second_trigger_buf = bufnr() | endif
-      ]])
-      request('nvim_command', [[edit test_a | badd test_b]])
-      request('nvim_command', [[normal! aa\<Esc>]])
-      request('nvim_command', [[let g:buf_a = bufnr()]])
-      request('nvim_command', [[bn]])
-      request('nvim_command', [[wa]])
-      os.remove('test_a')
-      eq({ 2, true }, { eval('g:modified'), eval('g:buf_a') == eval('g:second_trigger_buf') })
-    end)
-
-    it('OptionSet triggers correctly when modified changes', function()
-      command([[
-        autocmd OptionSet modified call add(g:messages, string(!!v:option_old) . ' -> ' . string(!!v:option_new) . ' - actual: ' . &modified)
-      ]])
-      command('let g:messages = []')
-      local fname = t.tmpname()
-      command('new ' .. fname)
-      command("call setline(1, 'hi')")
-      command('write')
-      command('set modified')
-      eq({
-        '0 -> 1 - actual: 1',
-        '1 -> 0 - actual: 0',
-        '0 -> 1 - actual: 1',
-      }, eval('g:messages'))
-      os.remove(fname)
-    end)
-  end)
 end)
diff --git a/test/functional/autocmd/optionset_spec.lua b/test/functional/autocmd/optionset_spec.lua
new file mode 100644
index 0000000000..3bfc7b89fc
--- /dev/null
+++ b/test/functional/autocmd/optionset_spec.lua
@@ -0,0 +1,59 @@
+local t = require('test.testutil')
+local n = require('test.functional.testnvim')()
+
+local eq = t.eq
+local eval = n.eval
+local clear = n.clear
+local command = n.command
+local source = n.source
+local request = n.request
+
+describe('autocmd', function()
+  describe('OptionSet modified', function()
+    before_each(clear)
+
+    it('is triggered when modified and un-modified', function()
+      source([[
+      let g:modified = 0
+      autocmd OptionSet modified let g:modified += 1
+      ]])
+      request('nvim_command', [[normal! aa\<Esc>]])
+      eq(1, eval('g:modified'))
+      request('nvim_command', [[normal! u]])
+      eq(2, eval('g:modified'))
+    end)
+
+    it('triggers when writes non-current buffer #32817', function()
+      source([[
+      let g:modified = 0
+      let g:second_trigger_buf = 0
+      autocmd OptionSet modified let g:modified += 1 | if g:modified == 2 | let g:second_trigger_buf = bufnr() | endif
+      ]])
+      request('nvim_command', [[edit test_a | badd test_b]])
+      request('nvim_command', [[normal! aa\<Esc>]])
+      request('nvim_command', [[let g:buf_a = bufnr()]])
+      request('nvim_command', [[bn]])
+      request('nvim_command', [[wa]])
+      os.remove('test_a')
+      eq({ 2, true }, { eval('g:modified'), eval('g:buf_a') == eval('g:second_trigger_buf') })
+    end)
+
+    it('OptionSet triggers correctly when modified changes', function()
+      command([[
+        autocmd OptionSet modified call add(g:messages, string(!!v:option_old) . ' -> ' . string(!!v:option_new) . ' - actual: ' . &modified)
+      ]])
+      command('let g:messages = []')
+      local fname = t.tmpname()
+      command('new ' .. fname)
+      command("call setline(1, 'hi')")
+      command('write')
+      command('set modified')
+      eq({
+        '0 -> 1 - actual: 1',
+        '1 -> 0 - actual: 0',
+        '0 -> 1 - actual: 1',
+      }, eval('g:messages'))
+      os.remove(fname)
+    end)
+  end)
+end)