27 files changed, 255 insertions, 135 deletions
diff --git a/runtime/autoload/health/lsp.vim b/runtime/autoload/health/lsp.vim
new file mode 100644
index 0000000000..2d2ba91cdf
--- /dev/null
+++ b/runtime/autoload/health/lsp.vim
@@ -0,0 +1,5 @@
+function! health#lsp#check() abort
+  call health#report_start('Checking language server client configuration')
+  lua require 'vim.lsp.health'.check_health()
+endfunction
+
diff --git a/runtime/doc/autocmd.txt b/runtime/doc/autocmd.txt
index 03e182cb33..960148d506 100644
--- a/runtime/doc/autocmd.txt
+++ b/runtime/doc/autocmd.txt
@@ -798,9 +798,10 @@ QuickFixCmdPost			Like QuickFixCmdPre, but after a quickfix
 							*QuitPre*
 QuitPre				When using `:quit`, `:wq` or `:qall`, before
 				deciding whether it closes the current window
-				or quits Vim.  Can be used to close any
-				non-essential window if the current window is
-				the last ordinary window.
+				or quits Vim.  For `:wq` the buffer is written
+				before QuitPre is triggered.  Can be used to
+				close any non-essential window if the current
+				window is the last ordinary window.
 				See also |ExitPre|, ||WinClosed|.
 							*RemoteReply*
 RemoteReply			When a reply from a Vim that functions as
diff --git a/runtime/doc/cmdline.txt b/runtime/doc/cmdline.txt
index 689fb1ecd2..70a465f636 100644
--- a/runtime/doc/cmdline.txt
+++ b/runtime/doc/cmdline.txt
@@ -1067,7 +1067,7 @@ in Normal mode and Insert mode.
 It is possible to use ":", "/" and other commands that use the command-line,
 but it's not possible to open another command-line window then.  There is no
 nesting.
-							*E11*
+							*E11* *E1188*
 The command-line window is not a normal window.  It is not possible to move to
 another window or edit another buffer.  All commands that would do this are
 disabled in the command-line window.  Of course it _is_ possible to execute
diff --git a/runtime/doc/deprecated.txt b/runtime/doc/deprecated.txt
index 3b5287ee44..861aed4884 100644
--- a/runtime/doc/deprecated.txt
+++ b/runtime/doc/deprecated.txt
@@ -14,6 +14,7 @@ updated.
 
 API ~
 *nvim_buf_clear_highlight()*	Use |nvim_buf_clear_namespace()| instead.
+*nvim_buf_set_virtual_text()*	Use |nvim_buf_set_extmark()| instead.
 *nvim_command_output()*		Use |nvim_exec()| instead.
 *nvim_execute_lua()*		Use |nvim_exec_lua()| instead.
 
@@ -54,6 +55,8 @@ Functions ~
 			without stopping the job. Use chanclose(id) to close
 			any socket.
 
+Lua ~
+*vim.register_keystroke_callback()* Use |vim.on_key()| instead.
 
 Modifiers ~
 *cpo-<*
diff --git a/runtime/doc/develop.txt b/runtime/doc/develop.txt
index 60a3f870a9..14f35acce3 100644
--- a/runtime/doc/develop.txt
+++ b/runtime/doc/develop.txt
@@ -127,14 +127,20 @@ Sometimes a GUI or other application may want to force a provider to
 
 DOCUMENTATION						*dev-doc*
 
-- Do not prefix help tags with "nvim-". Use |vim_diff.txt| to document
-  differences from Vim; no other distinction is necessary.
-- If a Vim feature is removed, delete its help section and move its tag to
-  |vim_diff.txt|.
-- Move deprecated features to |deprecated.txt|.
+- "Just say it". Avoid mushy, colloquial phrasing in all documentation
+  (docstrings, user manual, website materials, newsletters, …). Don't mince
+  words. Personality and flavor, used sparingly, are welcome--but in general,
+  optimize for the reader's time and energy: be "precise yet concise".
+    - Prefer the active voice: "Foo does X", not "X is done by Foo".
+- Vim differences:
+    - Do not prefix help tags with "nvim-". Use |vim_diff.txt| to catalog
+      differences from Vim; no other distinction is necessary.
+    - If a Vim feature is removed, delete its help section and move its tag to
+      |vim_diff.txt|.
+- Mention deprecated features in |deprecated.txt| and delete their old doc.
 - Use consistent language.
-    - "terminal" in a help tag always means "the embedded terminal emulator", not
-      "the user host terminal".
+    - "terminal" in a help tag always means "the embedded terminal emulator",
+      not "the user host terminal".
     - Use "tui-" to prefix help tags related to the host terminal, and "TUI"
       in prose if possible.
 - Docstrings: do not start parameter descriptions with "The" or "A" unless it
@@ -222,13 +228,13 @@ LUA							*dev-lua*
 
 - Keep the core Lua modules |lua-stdlib| simple. Avoid elaborate OOP or
   pseudo-OOP designs. Plugin authors just want functions to call, they don't
-  want to learn a big, fancy inheritance hierarchy. So we should avoid complex
-  objects: tables are usually better.
+  want to learn a big, fancy inheritance hierarchy. Thus avoid specialized
+  objects; tables or values are usually better.
 
 
 API							*dev-api*
 
-Use this template to name new API functions:
+Use this template to name new RPC |API| functions:
     nvim_{thing}_{action}_{arbitrary-qualifiers}
 
 If the function acts on an object then {thing} is the name of that object
@@ -356,4 +362,19 @@ External UIs are expected to implement these common features:
   published in this event. See also "mouse_on", "mouse_off".
 
 
+NAMING							*dev-naming*
+
+Naming is important. Consistent naming in the API and UI helps both users and
+developers discover and intuitively understand related concepts ("families"),
+and reduces cognitive burden. Discoverability encourages code re-use and
+likewise avoids redundant, overlapping mechanisms, which reduces code
+surface-area, and thereby minimizes bugs...
+
+Naming conventions ~
+
+Use the "on_" prefix to name event handlers and also the interface for
+"registering" such handlers (on_key). The dual nature is acceptable to avoid
+a confused collection of naming conventions for these related concepts.
+
+
  vim:tw=78:ts=8:noet:ft=help:norl:
diff --git a/runtime/doc/diff.txt b/runtime/doc/diff.txt
index a9e2a0d522..6115a5d235 100644
--- a/runtime/doc/diff.txt
+++ b/runtime/doc/diff.txt
@@ -334,9 +334,11 @@ between file1 and file2: >
 
 The ">" is replaced with the value of 'shellredir'.
 
-The output of "diff" must be a normal "ed" style diff or a unified diff.  Do
-NOT use a context diff.  This example explains the format that Vim expects for
-the "ed" style diff: >
+The output of "diff" must be a normal "ed" style diff or a unified diff.  A
+context diff will NOT work.  For a unified diff no context lines can be used.
+Using "diff -u" will NOT work, use "diff -U0".
+
+This example explains the format that Vim expects for the "ed" style diff: >
 
 	1a2
 	> bbb
diff --git a/runtime/doc/eval.txt b/runtime/doc/eval.txt
index 87240831a2..e6405145cd 100644
--- a/runtime/doc/eval.txt
+++ b/runtime/doc/eval.txt
@@ -2368,6 +2368,7 @@ matchstr({expr}, {pat}[, {start}[, {count}]])
 matchstrpos({expr}, {pat}[, {start}[, {count}]])
 				List	{count}'th match of {pat} in {expr}
 max({expr})			Number	maximum value of items in {expr}
+menu_get({path} [, {modes}])	List	description of |menus| matched by {path}
 min({expr})			Number	minimum value of items in {expr}
 mkdir({name} [, {path} [, {prot}]])
 				Number	create directory {name}
@@ -5873,8 +5874,8 @@ jobwait({jobs}[, {timeout}])				*jobwait()*
 		Waits for jobs and their |on_exit| handlers to complete.
 
 		{jobs} is a List of |job-id|s to wait for.
-		{timeout} is the maximum waiting time in milliseconds, -1
-		means forever.
+		{timeout} is the maximum waiting time in milliseconds. If
+		omitted or -1, wait forever.
 
 		Timeout of 0 can be used to check the status of a job: >
 			let running = jobwait([{job-id}], 0)[0] == -1
@@ -6400,7 +6401,7 @@ matcharg({nr})							*matcharg()*
 		Highlighting matches using the |:match| commands are limited
 		to three matches. |matchadd()| does not have this limitation.
 
-matchdelete({id} [, {win})		       *matchdelete()* *E802* *E803*
+matchdelete({id} [, {win}])		       *matchdelete()* *E802* *E803*
 		Deletes a match with ID {id} previously defined by |matchadd()|
 		or one of the |:match| commands.  Returns 0 if successful,
 		otherwise -1.  See example for |matchadd()|.  All matches can
@@ -6479,7 +6480,7 @@ max({expr})	Return the maximum value of all items in {expr}.
 		Can also be used as a |method|: >
 			mylist->max()
 
-menu_get({path}, {modes})				*menu_get()*
+menu_get({path} [, {modes}])				*menu_get()*
 		Returns a |List| of |Dictionaries| describing |menus| (defined
 		by |:menu|, |:amenu|, …), including |hidden-menus|.
 
@@ -8364,7 +8365,7 @@ sinh({expr})						*sinh()*
 		Can also be used as a |method|: >
 			Compute()->sinh()
 
-sockconnect({mode}, {address}, {opts})			 *sockconnect()*
+sockconnect({mode}, {address} [, {opts}])		 *sockconnect()*
 		Connect a socket to an address. If {mode} is "pipe" then
 		{address} should be the path of a named pipe. If {mode} is
 		"tcp" then {address} should be of the form "host:port" where
@@ -8376,7 +8377,7 @@ sockconnect({mode}, {address}, {opts})			 *sockconnect()*
 		|rpcrequest()| and |rpcnotify()| to communicate with a RPC
 		socket.
 
-		{opts} is a dictionary with these keys:
+		{opts} is an optional dictionary with these keys:
 		  |on_data| : callback invoked when data was read from socket
 		  data_buffered : read socket data in |channel-buffered| mode.
 		  rpc     : If set, |msgpack-rpc| will be used to communicate
@@ -9275,7 +9276,7 @@ tanh({expr})						*tanh()*
 
 		Can also be used as a |method|: >
 			Compute()->tanh()
-
+<
 							*timer_info()*
 timer_info([{id}])
 		Return a list with information about timers.
diff --git a/runtime/doc/ft_sql.txt b/runtime/doc/ft_sql.txt
index f38c8edbf3..53a99a9e1d 100644
--- a/runtime/doc/ft_sql.txt
+++ b/runtime/doc/ft_sql.txt
@@ -436,7 +436,7 @@ the space bar):
 			     replace the column list with the list of tables.
 			   - This allows you to quickly drill down into a
 			     table to view its columns and back again.
-			   - <Right> and <Left> can be also be chosen via
+			   - <Right> and <Left> can also be chosen via
 			     your |init.vim| >
                                 let g:ftplugin_sql_omni_key_right = '<Right>'
                                 let g:ftplugin_sql_omni_key_left  = '<Left>'
diff --git a/runtime/doc/index.txt b/runtime/doc/index.txt
index 69a13557d1..9a279ad880 100644
--- a/runtime/doc/index.txt
+++ b/runtime/doc/index.txt
@@ -1608,7 +1608,7 @@ tag		command		action ~
 |:tab|		:tab		create new tab when opening new window
 |:tag|		:ta[g]		jump to tag
 |:tags|		:tags		show the contents of the tag stack
-|:tcd|		:tcd		change directory for tab page
+|:tcd|		:tc[d]		change directory for tab page
 |:tchdir|	:tch[dir]	change directory for tab page
 |:terminal|	:te[rminal]	open a terminal buffer
 |:tfirst|	:tf[irst]	jump to first matching tag
diff --git a/runtime/doc/job_control.txt b/runtime/doc/job_control.txt
index bf01e8e266..6a9d865c40 100644
--- a/runtime/doc/job_control.txt
+++ b/runtime/doc/job_control.txt
@@ -19,7 +19,7 @@ Job Id							*job-id*
 Each job is identified by an integer id, unique for the life of the current
 Nvim session. Each job-id is a valid |channel-id|: they share the same "key
 space". Functions like |jobstart()| return job ids; functions like
-|jobsend()|, |jobstop()|, |rpcnotify()|, and |rpcrequest()| take job ids.
+|jobstop()|, |chansend()|, |rpcnotify()|, and |rpcrequest()| take job ids.
 
 Job stdio streams form a |channel| which can send and receive raw bytes or
 |msgpack-rpc| messages.
@@ -28,7 +28,7 @@ Job stdio streams form a |channel| which can send and receive raw bytes or
 Usage							*job-control-usage*
 
 To control jobs, use the "job…" family of functions: |jobstart()|,
-|jobsend()|, |jobstop()|.
+|jobstop()|, etc.
 
 Example: >
 
diff --git a/runtime/doc/lua.txt b/runtime/doc/lua.txt
index a44b2e42f5..5d600eae99 100644
--- a/runtime/doc/lua.txt
+++ b/runtime/doc/lua.txt
@@ -576,11 +576,11 @@ If you want to exclude visual selections from highlighting on yank, use
 vim.highlight.on_yank({opts})                         *vim.highlight.on_yank()*
         Highlights the yanked text. The fields of the optional dict {opts}
         control the highlight:
-          - {higroup} highlight group for yanked region (default `"IncSearch"`)
+          - {higroup} highlight group for yanked region (default |hl-IncSearch|)
           - {timeout} time in ms before highlight is cleared (default `150`)
           - {on_macro} highlight when executing macro (default `false`)
           - {on_visual} highlight when yanking visual selection (default `true`)
-          - {event} event structure (default `vim.v.event`)
+          - {event} event structure (default |v:event|)
 
 vim.highlight.range({bufnr}, {ns}, {higroup}, {start}, {finish}, {rtype}, {inclusive})
                                                        *vim.highlight.range()*
@@ -1243,37 +1243,6 @@ region({bufnr}, {pos1}, {pos2}, {regtype}, {inclusive})         *vim.region()*
                 Return: ~
                     region lua table of the form {linenr = {startcol,endcol}}
 
-                                           *vim.register_keystroke_callback()*
-register_keystroke_callback({fn}, {ns_id})
-                Register a lua {fn} with an {id} to be run after every
-                keystroke.
-
-                If {fn} is nil, it removes the callback for the associated
-                {ns_id}
-                Note:
-                    {fn} will not be cleared from |nvim_buf_clear_namespace()|
-
-                Note:
-                    {fn} will receive the keystrokes after mappings have been
-                    evaluated
-
-                Parameters: ~
-                    {fn}     function: Function to call. It should take one
-                          argument, which is a string. The string will contain
-                          the literal keys typed. See |i_CTRL-V|
-                    {ns_id}  number? Namespace ID. If not passed or 0, will
-                             generate and return a new namespace ID from
-                             |nvim_create_namesapce()|
-
-                Return: ~
-                    number Namespace ID associated with {fn}
-
-                Note:
-                    {fn} will be automatically removed if an error occurs
-                    while calling. This is to prevent the annoying situation
-                    of every keystroke erroring while trying to remove a
-                    broken callback.
-
 schedule_wrap({cb})                                      *vim.schedule_wrap()*
                 Defers callback `cb` until the Nvim API is safe to call.
 
diff --git a/runtime/doc/options.txt b/runtime/doc/options.txt
index 475ccb66b3..d7bd91ad4f 100644
--- a/runtime/doc/options.txt
+++ b/runtime/doc/options.txt
@@ -6118,6 +6118,8 @@ A jump table for the options with a short description can be found at |Q_op|.
 'switchbuf' 'swb'	string	(default "uselast")
 			global
 	This option controls the behavior when switching between buffers.
+	Mostly for |quickfix| commands some values are also used for other
+ 	commands, as mentioned below.
 	Possible values (comma separated list):
 	   useopen	If included, jump to the first open window that
 			contains the specified buffer (if there is one).
diff --git a/runtime/doc/quickfix.txt b/runtime/doc/quickfix.txt
index 563fb0c962..9c1f584415 100644
--- a/runtime/doc/quickfix.txt
+++ b/runtime/doc/quickfix.txt
@@ -1333,7 +1333,8 @@ Basic items
 	%o		module name (finds a string)
 	%l		line number (finds a number)
 	%c		column number (finds a number representing character
-			column of the error, (1 <tab> == 1 character column))
+			column of the error, byte index, a <tab> is 1
+			character column)
 	%v		virtual column number (finds a number representing
 			screen column of the error (1 <tab> == 8 screen
 			columns))
diff --git a/runtime/doc/spell.txt b/runtime/doc/spell.txt
index 22d7cdf491..03c00c8495 100644
--- a/runtime/doc/spell.txt
+++ b/runtime/doc/spell.txt
@@ -1127,10 +1127,10 @@ flag to avoid lots of errors.
 CIRCUMFIX						*spell-CIRCUMFIX*
 
 The CIRCUMFIX flag means a prefix and suffix must be added at the same time.
-If a prefix has the CIRCUMFIX flag than only suffixes with the CIRCUMFIX flag
+If a prefix has the CIRCUMFIX flag then only suffixes with the CIRCUMFIX flag
 can be added, and the other way around.
-An alternative is to only specify the suffix, and give the that suffix two
-flags: The required prefix and the NEEDAFFIX flag.  |spell-NEEDAFFIX|
+An alternative is to only specify the suffix, and give that suffix two flags:
+the required prefix and the NEEDAFFIX flag.  |spell-NEEDAFFIX|
 
 
 PFXPOSTPONE						*spell-PFXPOSTPONE*
diff --git a/runtime/doc/starting.txt b/runtime/doc/starting.txt
index d6b54fbd01..87a48e6d2a 100644
--- a/runtime/doc/starting.txt
+++ b/runtime/doc/starting.txt
@@ -329,12 +329,12 @@ argument.
 -w{number}	Set the 'window' option to {number}.
 
 							*-w*
--w {scriptout}	All the characters that you type are recorded in the file
-		"scriptout", until you exit Vim.  This is useful if you want
-		to create a script file to be used with "vim -s" or
-		":source!".  When the "scriptout" file already exists, new
-		characters are appended.  See also |complex-repeat|.
-		{scriptout} cannot start with a digit.
+-w {scriptout}	All keys that you type are recorded in the file "scriptout",
+		until you exit Vim.  Useful to create a script file to be used
+		with "vim -s" or ":source!".  Appends to the "scriptout" file
+		if it already exists. {scriptout} cannot start with a digit.
+		See also |vim.on_key()|.
+		See also |complex-repeat|.
 
 							*-W*
 -W {scriptout}	Like -w, but do not append, overwrite an existing file.
diff --git a/runtime/doc/usr_08.txt b/runtime/doc/usr_08.txt
index 8e69307a94..8ccaa73006 100644
--- a/runtime/doc/usr_08.txt
+++ b/runtime/doc/usr_08.txt
@@ -235,7 +235,7 @@ windows like this:
 	+----------------------------------+
 
 Clearly the last one should be at the top.  Go to that window (using CTRL-W w)
-and the type this command: >
+and then type this command: >
 
 	CTRL-W K
 
diff --git a/runtime/doc/usr_09.txt b/runtime/doc/usr_09.txt
index 757d13e0f3..8084d13b5d 100644
--- a/runtime/doc/usr_09.txt
+++ b/runtime/doc/usr_09.txt
@@ -109,7 +109,7 @@ when the 'wrap' option has been reset (more about that later).
 
 When there are vertically split windows, only the windows on the right side
 will have a scrollbar.  However, when you move the cursor to a window on the
-left, it will be this one the that scrollbar controls.  This takes a bit of
+left, it will be this one that the scrollbar controls.  This takes a bit of
 time to get used to.
    When you work with vertically split windows, consider adding a scrollbar on
 the left.  This can be done with a menu item, or with the 'guioptions' option:
diff --git a/runtime/doc/vim_diff.txt b/runtime/doc/vim_diff.txt
index 4b134926a2..a5fcef2800 100644
--- a/runtime/doc/vim_diff.txt
+++ b/runtime/doc/vim_diff.txt
@@ -6,16 +6,16 @@
 
 Differences between Nvim and Vim			       *vim-differences*
 
-Nvim differs from Vim in many ways, although editor and VimL features are
-mostly identical.  This document is a complete and centralized reference of
-the differences.
+Nvim differs from Vim in many ways, although editor and Vimscript (not
+Vim9script) features are mostly identical.  This document is a complete and
+centralized reference of the differences.
 
 				      Type |gO| to see the table of contents.
 
 ==============================================================================
 1. Configuration					    *nvim-config*
 
-- Use `$XDG_CONFIG_HOME/nvim/init.vim` instead of `.vimrc` for configuration.
+- Use `$XDG_CONFIG_HOME/nvim/init.vim` instead of `.vimrc` for your |config|.
 - Use `$XDG_CONFIG_HOME/nvim` instead of `.vim` to store configuration files.
 - Use `$XDG_DATA_HOME/nvim/shada/main.shada` instead of `.viminfo` for persistent
   session information.  |shada|
@@ -78,6 +78,8 @@ the differences.
 
 Default Mappings ~
 							*default-mappings*
+Nvim creates the following default mappings at |startup|. You can disable any
+of these in your config by simply removing the mapping, e.g. ":unmap Y".
 >
 	nnoremap Y y$
 	nnoremap <C-L> <Cmd>nohlsearch<Bar>diffupdate<CR><C-L>
@@ -101,17 +103,19 @@ nvim_cmdwin:
 MAJOR COMPONENTS ~
 
 API				|API|
-Lua scripting			|lua|
 Job control			|job-control|
-Remote plugins			|remote-plugin|
+LSP framework			|lsp|
+Lua scripting			|lua|
+Parsing engine			|treesitter|
 Providers
   Clipboard			|provider-clipboard|
   Node.js plugins		|provider-nodejs|
   Python plugins		|provider-python|
   Ruby plugins			|provider-ruby|
+Remote plugins			|remote-plugin|
 Shared data			|shada|
-Embedded terminal		|terminal|
-VimL parser			|nvim_parse_expression()|
+Terminal emulator		|terminal|
+Vimscript parser		|nvim_parse_expression()|
 XDG base directories		|xdg|
 
 USER EXPERIENCE  ~
@@ -160,7 +164,7 @@ FEATURES ~
 
 Command-line highlighting:
   The expression prompt (|@=|, |c_CTRL-R_=|, |i_CTRL-R_=|) is highlighted
-  using a built-in VimL expression parser. |expr-highlight|
+  using a built-in Vimscript expression parser. |expr-highlight|
 					*E5408* *E5409*
   |input()|, |inputdialog()| support custom highlighting. |input()-highlight|
 					*g:Nvim_color_cmdline*
@@ -413,7 +417,7 @@ TUI:
 UI/Display:
   |Visual| selection highlights the character at cursor. |visual-use|
 
-VimL (Vim script) compatibility:
+Vimscript compatibility:
   `count` does not alias to |v:count|
   `errmsg` does not alias to |v:errmsg|
   `shell_error` does not alias to |v:shell_error|
diff --git a/runtime/doc/visual.txt b/runtime/doc/visual.txt
index f7828f0289..111588e43a 100644
--- a/runtime/doc/visual.txt
+++ b/runtime/doc/visual.txt
@@ -419,7 +419,7 @@ abcdefghijklmnopqrstuvwxyz
 
 abcdefghijklmnSTRINGopqrstuvwxyz
 abc	      STRING  defghijklmnopqrstuvwxyz
-abcdef  ghi   STRING	jklmnopqrstuvwxyz
+abcdef  ghi   STRING  	jklmnopqrstuvwxyz
 abcdefghijklmnSTRINGopqrstuvwxyz
 
 2. fo<C-v>3j$ASTRING<ESC>					*v_b_A_example*
diff --git a/runtime/indent/python.vim b/runtime/indent/python.vim
index f9236e63c7..307b7f656b 100644
--- a/runtime/indent/python.vim
+++ b/runtime/indent/python.vim
@@ -2,7 +2,7 @@
 " Language:		Python
 " Maintainer:		Bram Moolenaar <Bram@vim.org>
 " Original Author:	David Bustos <bustos@caltech.edu>
-" Last Change:		2019 Feb 21
+" Last Change:		2021 May 26
 
 " Only load this indent file when no other was loaded.
 if exists("b:did_indent")
@@ -191,7 +191,7 @@ function GetPythonIndent(lnum)
   if getline(a:lnum) =~ '^\s*\(elif\|else\)\>'
 
     " Unless the previous line was a one-liner
-    if getline(plnumstart) =~ '^\s*\(for\|if\|try\)\>'
+    if getline(plnumstart) =~ '^\s*\(for\|if\|elif\|try\)\>'
       return plindent
     endif
 
diff --git a/runtime/lua/vim/lsp/buf.lua b/runtime/lua/vim/lsp/buf.lua
index 264d7c0247..8bfcd90f12 100644
--- a/runtime/lua/vim/lsp/buf.lua
+++ b/runtime/lua/vim/lsp/buf.lua
@@ -249,13 +249,34 @@ end
 ---@param new_name (string) If not provided, the user will be prompted for a new
 ---name using |input()|.
 function M.rename(new_name)
-  -- TODO(ashkan) use prepareRename
-  -- * result: [`Range`](#range) \| `{ range: Range, placeholder: string }` \| `null` describing the range of the string to rename and optionally a placeholder text of the string content to be renamed. If `null` is returned then it is deemed that a 'textDocument/rename' request is not valid at the given position.
   local params = util.make_position_params()
-  new_name = new_name or npcall(vfn.input, "New Name: ", vfn.expand('<cword>'))
-  if not (new_name and #new_name > 0) then return end
-  params.newName = new_name
-  request('textDocument/rename', params)
+  local function prepare_rename(err, result)
+    if err == nil and result == nil then
+      vim.notify('nothing to rename', vim.log.levels.INFO)
+      return
+    end
+    if result and result.placeholder then
+      new_name = new_name or npcall(vfn.input, "New Name: ", result.placeholder)
+    elseif result and result.start and result['end'] and
+      result.start.line == result['end'].line then
+      local line = vfn.getline(result.start.line+1)
+      local start_char = result.start.character+1
+      local end_char = result['end'].character
+      new_name = new_name or npcall(vfn.input, "New Name: ", string.sub(line, start_char, end_char))
+    else
+      -- fallback to guessing symbol using <cword>
+      --
+      -- this can happen if the language server does not support prepareRename,
+      -- returns an unexpected response, or requests for "default behavior"
+      --
+      -- see https://microsoft.github.io/language-server-protocol/specification#textDocument_prepareRename
+      new_name = new_name or npcall(vfn.input, "New Name: ", vfn.expand('<cword>'))
+    end
+    if not (new_name and #new_name > 0) then return end
+    params.newName = new_name
+    request('textDocument/rename', params)
+  end
+  request('textDocument/prepareRename', params, prepare_rename)
 end
 
 --- Lists all the references to the symbol under the cursor in the quickfix window.
diff --git a/runtime/lua/vim/lsp/health.lua b/runtime/lua/vim/lsp/health.lua
new file mode 100644
index 0000000000..855679a2df
--- /dev/null
+++ b/runtime/lua/vim/lsp/health.lua
@@ -0,0 +1,27 @@
+local M = {}
+
+--- Performs a healthcheck for LSP
+function M.check_health()
+  local report_info = vim.fn['health#report_info']
+  local report_warn = vim.fn['health#report_warn']
+
+  local log = require('vim.lsp.log')
+  local current_log_level = log.get_level()
+  local log_level_string = log.levels[current_log_level]
+  report_info(string.format("LSP log level : %s", log_level_string))
+
+  if current_log_level < log.levels.WARN then
+    report_warn(string.format("Log level %s will cause degraded performance and high disk usage", log_level_string))
+  end
+
+  local log_path = vim.lsp.get_log_path()
+  report_info(string.format("Log path: %s", log_path))
+
+  local log_size = vim.loop.fs_stat(log_path).size
+
+  local report_fn = (log_size / 1000000 > 100 and report_warn or report_info)
+  report_fn(string.format("Log size: %d KB", log_size / 1000 ))
+end
+
+return M
+
diff --git a/runtime/lua/vim/lsp/log.lua b/runtime/lua/vim/lsp/log.lua
index a2d5c3a774..5d2e396cc5 100644
--- a/runtime/lua/vim/lsp/log.lua
+++ b/runtime/lua/vim/lsp/log.lua
@@ -32,6 +32,17 @@ do
 
   vim.fn.mkdir(vim.fn.stdpath('cache'), "p")
   local logfile = assert(io.open(logfilename, "a+"))
+
+  local log_info = vim.loop.fs_stat(logfilename)
+  if log_info and log_info.size > 1e9 then
+    local warn_msg = string.format(
+      "LSP client log is large (%d MB): %s",
+      log_info.size / (1000 * 1000),
+      logfilename
+    )
+    vim.notify(warn_msg)
+  end
+
   -- Start message for logging
   logfile:write(string.format("[ START ] %s ] LSP logging initiated\n", os.date(log_date_format)))
   for level, levelnr in pairs(log.levels) do
@@ -88,6 +99,11 @@ function log.set_level(level)
   end
 end
 
+--- Gets the current log level.
+function log.get_level()
+  return current_log_level
+end
+
 --- Checks whether the level is sufficient for logging.
 ---@param level number log level
 ---@returns (bool) true if would log, false if not
diff --git a/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim b/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
index ae1274f81f..2914e2bc4d 100644
--- a/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
+++ b/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
@@ -2,7 +2,7 @@
 "
 " Author: Bram Moolenaar
 " Copyright: Vim license applies, see ":help license"
-" Last Change: 2021 May 16
+" Last Change: 2021 May 18
 "
 " WORK IN PROGRESS - Only the basics work
 " Note: On MS-Windows you need a recent version of gdb.  The one included with
@@ -181,6 +181,15 @@ func s:CloseBuffers()
   unlet! s:gdbwin
 endfunc
 
+func s:CheckGdbRunning()
+  if nvim_get_chan_info(s:gdb_job_id) == {}
+      echoerr string(g:termdebugger) . ' exited unexpectedly'
+      call s:CloseBuffers()
+      return ''
+  endif
+  return 'ok'
+endfunc
+
 func s:StartDebug_term(dict)
   " Open a terminal window without a job, to run the debugged program in.
   execute s:vertical ? 'vnew' : 'new'
@@ -229,7 +238,7 @@ func s:StartDebug_term(dict)
   let gdb_args = get(a:dict, 'gdb_args', [])
   let proc_args = get(a:dict, 'proc_args', [])
 
-  let cmd = [g:termdebugger, '-quiet', '-tty', pty] + gdb_args
+  let cmd = [g:termdebugger, '-quiet', '-tty', pty, '--eval-command', 'echo startupdone\n'] + gdb_args
   "call ch_log('executing "' . join(cmd) . '"')
   execute 'new'
   let s:gdb_job_id = termopen(cmd, {'on_exit': function('s:EndTermDebug')})
@@ -246,9 +255,28 @@ func s:StartDebug_term(dict)
   let s:gdbbuf = gdb_job_info['buffer']
   let s:gdbwin = win_getid(winnr())
 
-  " Set arguments to be run.  First wait a bit to make detecting gdb a bit
-  " more reliable.
-  sleep 200m
+  " Wait for the "startupdone" message before sending any commands.
+  let try_count = 0
+  while 1
+    if s:CheckGdbRunning() != 'ok'
+      return
+    endif
+
+    for lnum in range(1, 200)
+      if get(getbufline(s:gdbbuf, lnum), 0, '') =~ 'startupdone'
+    let try_count = 9999
+    break
+      endif
+    endfor
+    let try_count += 1
+    if try_count > 300
+      " done or give up after five seconds
+      break
+    endif
+    sleep 10m
+  endwhile
+
+  " Set arguments to be run.
   if len(proc_args)
     call chansend(s:gdb_job_id, 'set args ' . join(proc_args) . "\r")
   endif
@@ -260,9 +288,7 @@ func s:StartDebug_term(dict)
   " why the debugger doesn't work.
   let try_count = 0
   while 1
-    if nvim_get_chan_info(s:gdb_job_id) == {}
-      echoerr string(g:termdebugger) . ' exited unexpectedly'
-      call s:CloseBuffers()
+    if s:CheckGdbRunning() != 'ok'
       return
     endif
 
diff --git a/runtime/syntax/c.vim b/runtime/syntax/c.vim
index d07aaf2658..20f8632006 100644
--- a/runtime/syntax/c.vim
+++ b/runtime/syntax/c.vim
@@ -1,7 +1,7 @@
 " Vim syntax file
 " Language:	C
 " Maintainer:	Bram Moolenaar <Bram@vim.org>
-" Last Change:	2021 Jan 11
+" Last Change:	2021 May 24
 
 " Quit when a (custom) syntax file was already loaded
 if exists("b:current_syntax")
@@ -414,6 +414,9 @@ if exists("c_autodoc")
   syn cluster cPreProcGroup add=cAutodocReal
 endif
 
+" be able to fold #pragma regions
+syn region	cPragma		start="^\s*#pragma\s\+region\>" end="^\s*#pragma\s\+endregion\>" transparent keepend extend fold
+
 " Highlight User Labels
 syn cluster	cMultiGroup	contains=cIncluded,cSpecial,cCommentSkip,cCommentString,cComment2String,@cCommentGroup,cCommentStartError,cUserCont,cUserLabel,cBitField,cOctalZero,cCppOutWrapper,cCppInWrapper,@cCppOutInGroup,cFormat,cNumber,cFloat,cOctal,cOctalError,cNumbersCom,cCppParen,cCppBracket,cCppString
 if s:ft ==# 'c' || exists("cpp_no_cpp11")
diff --git a/runtime/syntax/cpp.vim b/runtime/syntax/cpp.vim
index ed38913f29..3ad79d5545 100644
--- a/runtime/syntax/cpp.vim
+++ b/runtime/syntax/cpp.vim
@@ -2,7 +2,7 @@
 " Language:	C++
 " Current Maintainer:	vim-jp (https://github.com/vim-jp/vim-cpp)
 " Previous Maintainer:	Ken Shan <ccshan@post.harvard.edu>
-" Last Change:	2021 Jan 12
+" Last Change:	2021 May 04
 
 " quit when a syntax file was already loaded
 if exists("b:current_syntax")
@@ -44,22 +44,40 @@ if !exists("cpp_no_cpp11")
   syn keyword cppConstant	ATOMIC_WCHAR_T_LOCK_FREE ATOMIC_SHORT_LOCK_FREE
   syn keyword cppConstant	ATOMIC_INT_LOCK_FREE ATOMIC_LONG_LOCK_FREE
   syn keyword cppConstant	ATOMIC_LLONG_LOCK_FREE ATOMIC_POINTER_LOCK_FREE
-  syn region cppRawString	matchgroup=cppRawStringDelimiter start=+\%(u8\|[uLU]\)\=R"\z([[:alnum:]_{}[\]#<>%:;.?*\+\-/\^&|~!=,"']\{,16}\)(+ end=+)\z1"+ contains=@Spell
+  syn region cppRawString	matchgroup=cppRawStringDelimiter start=+\%(u8\|[uLU]\)\=R"\z([[:alnum:]_{}[\]#<>%:;.?*\+\-/\^&|~!=,"']\{,16}\)(+ end=+)\z1"\(sv\|s\|_[_a-zA-Z][_a-zA-Z0-9]*\)\=+ contains=@Spell
   syn match cppCast		"\<\(const\|static\|dynamic\)_pointer_cast\s*<"me=e-1
   syn match cppCast		"\<\(const\|static\|dynamic\)_pointer_cast\s*$"
 endif
 
 " C++ 14 extensions
 if !exists("cpp_no_cpp14")
-  syn case ignore
-  syn match cppNumber		display "\<0b[01]\('\=[01]\+\)*\(u\=l\{0,2}\|ll\=u\)\>"
-  syn match cppNumber		display "\<[1-9]\('\=\d\+\)*\(u\=l\{0,2}\|ll\=u\)\>" contains=cFloat
-  syn match cppNumber		display "\<0x\x\('\=\x\+\)*\(u\=l\{0,2}\|ll\=u\)\>"
-  syn case match
+  syn match cppNumbers		display transparent "\<\d\|\.\d" contains=cppNumber,cppFloat
+  syn match cppNumber		display contained "\<0\([Uu]\=\([Ll]\|LL\|ll\)\|\([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppNumber		display contained "\<[1-9]\('\=\d\+\)*\([Uu]\=\([Ll]\|LL\|ll\)\|\([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppNumber		display contained "\<0\o\+\([Uu]\=\([Ll]\|LL\|ll\)\|\([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppNumber		display contained "\<0b[01]\('\=[01]\+\)*\([Uu]\=\([Ll]\|LL\|ll\)\|\([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppNumber		display contained "\<0x\x\('\=\x\+\)*\([Uu]\=\([Ll]\|LL\|ll\)\|\([Ll]\|LL\|ll\)\=[Uu]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppFloat		display contained "\<\d\+\.\d*\(e[-+]\=\d\+\)\=\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppFloat		display contained "\<\.\d\+\(e[-+]\=\d\+\)\=\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppFloat		display contained "\<\d\+e[-+]\=\d\+\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn region cppString		start=+\(L\|u\|u8\|U\|R\|LR\|u8R\|uR\|UR\)\="+ skip=+\\\\\|\\"\|\\$+ excludenl end=+"\(sv\|s\|_\i*\)\=+ end='$' contains=cSpecial,cFormat,@Spell
+endif
+
+" C++ 17 extensions
+if !exists("cpp_no_cpp17")
+  syn match cppCast		"\<reinterpret_pointer_cast\s*<"me=e-1
+  syn match cppCast		"\<reinterpret_pointer_cast\s*$"
+  syn match cppFloat		display contained "\<0x\x*\.\x\+p[-+]\=\d\+\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
+  syn match cppFloat		display contained "\<0x\x\+\.\=p[-+]\=\d\+\([FfLl]\|i[fl]\=\|h\|min\|s\|ms\|us\|ns\|_\i*\)\=\>"
 endif
 
 " C++ 20 extensions
 if !exists("cpp_no_cpp20")
+  syn match cppNumber		display contained "\<0\(y\|d\)\>"
+  syn match cppNumber		display contained "\<[1-9]\('\=\d\+\)*\(y\|d\)\>"
+  syn match cppNumber		display contained "\<0\o\+\(y\|d\)\>"
+  syn match cppNumber		display contained "\<0b[01]\('\=[01]\+\)*\(y\|d\)\>"
+  syn match cppNumber		display contained "\<0x\x\('\=\x\+\)*\(y\|d\)\>"
   syn keyword cppStatement	co_await co_return co_yield requires
   syn keyword cppStorageClass	consteval constinit
   syn keyword cppStructure	concept
@@ -67,12 +85,6 @@ if !exists("cpp_no_cpp20")
   syn keyword cppModule		import module export
 endif
 
-" C++ 17 extensions
-if !exists("cpp_no_cpp17")
-  syn match cppCast		"\<reinterpret_pointer_cast\s*<"me=e-1
-  syn match cppCast		"\<reinterpret_pointer_cast\s*$"
-endif
-
 " The minimum and maximum operators in GNU C++
 syn match cppMinMax "[<>]?"
 
@@ -90,7 +102,9 @@ hi def link cppBoolean		Boolean
 hi def link cppConstant		Constant
 hi def link cppRawStringDelimiter	Delimiter
 hi def link cppRawString		String
+hi def link cppString		String
 hi def link cppNumber		Number
+hi def link cppFloat		Number
 hi def link cppModule		Include
 
 let b:current_syntax = "cpp"
diff --git a/runtime/syntax/sh.vim b/runtime/syntax/sh.vim
index 48a0024b00..0ab9c0ad58 100644
--- a/runtime/syntax/sh.vim
+++ b/runtime/syntax/sh.vim
@@ -2,8 +2,8 @@
 " Language:		shell (sh) Korn shell (ksh) bash (sh)
 " Maintainer:		Charles E. Campbell <NcampObell@SdrPchip.AorgM-NOSPAM>
 " Previous Maintainer:	Lennart Schultz <Lennart.Schultz@ecmwf.int>
-" Last Change:		Nov 24, 2020
-" Version:		196
+" Last Change:		Feb 18, 2021
+" Version:		198
 " URL:		http://www.drchip.org/astronaut/vim/index.html#SYNTAX_SH
 " For options and settings, please use:      :help ft-sh-syntax
 " This file includes many ideas from Eric Brunet (eric.brunet@ens.fr) and heredoc fixes from Felipe Contreras
@@ -13,33 +13,35 @@ if exists("b:current_syntax")
   finish
 endif
 
-" trying to answer the question: which shell is /bin/sh, really?
-" If the user has not specified any of g:is_kornshell, g:is_bash, g:is_posix, g:is_sh, then guess.
-if getline(1) =~ '\<ksh$'
+" If the shell script itself specifies which shell to use, use it
+if getline(1) =~ '\<ksh\>'
  let b:is_kornshell = 1
-elseif getline(1) =~ '\<bash$'
+elseif getline(1) =~ '\<bash\>'
  let b:is_bash      = 1
-elseif getline(1) =~ '\<dash$'
+elseif getline(1) =~ '\<dash\>'
  let b:is_dash      = 1
 elseif !exists("g:is_kornshell") && !exists("g:is_bash") && !exists("g:is_posix") && !exists("g:is_sh") && !exists("g:is_dash")
+ " user did not specify which shell to use, and 
+ " the script itself does not specify which shell to use. FYI: /bin/sh is ambiguous.
+ " Assuming /bin/sh is executable, and if its a link, find out what it links to.
  let s:shell = ""
  if executable("/bin/sh")
   let s:shell = resolve("/bin/sh")
  elseif executable("/usr/bin/sh")
   let s:shell = resolve("/usr/bin/sh")
  endif
- if     s:shell =~ 'ksh$'
+ if     s:shell =~ '\<ksh\>'
   let b:is_kornshell= 1
- elseif s:shell =~ 'bash$'
+ elseif s:shell =~ '\<bash\>'
   let b:is_bash = 1
- elseif s:shell =~ 'dash$'
+ elseif s:shell =~ '\<dash\>'
   let b:is_dash = 1
  endif
  unlet s:shell
 endif
 
 " handling /bin/sh with is_kornshell/is_sh {{{1
-" b:is_sh is set when "#! /bin/sh" is found;
+" b:is_sh will be set when "#! /bin/sh" is found;
 " However, it often is just a masquerade by bash (typically Linux)
 " or kornshell (typically workstations with Posix "sh").
 " So, when the user sets "g:is_bash", "g:is_kornshell",
@@ -98,12 +100,14 @@ if g:sh_fold_enabled && &fdm == "manual"
  setl fdm=syntax
 endif
 
-" set up the syntax-highlighting iskeyword
+" set up the syntax-highlighting for iskeyword
 if (v:version == 704 && has("patch-7.4.1142")) || v:version > 704
- if exists("b:is_bash")
-  exe "syn iskeyword ".&iskeyword.",-,:"
- else
-  exe "syn iskeyword ".&iskeyword.",-"
+ if !exists("g:sh_syntax_isk") || (exists("g:sh_syntax_isk") && g:sh_syntax_isk)
+  if exists("b:is_bash")
+   exe "syn iskeyword ".&iskeyword.",-,:"
+  else
+   exe "syn iskeyword ".&iskeyword.",-"
+  endif
  endif
 endif
 
@@ -374,12 +378,11 @@ elseif !exists("g:sh_no_error")
  syn region  shExDoubleQuote	matchGroup=Error start=+\$"+ skip=+\\\\\|\\.+ end=+"+	contains=shStringSpecial
 endif
 syn region  shSingleQuote	matchgroup=shQuote start=+'+ end=+'+		contains=@Spell	nextgroup=shSpecialStart,shSpecialSQ
-syn region  shDoubleQuote	matchgroup=shQuote start=+\%(\%(\\\\\)*\\\)\@<!"+ skip=+\\.+ end=+"+	contains=@shDblQuoteList,shStringSpecial,@Spell	nextgroup=shSpecialStart
-syn region  shDoubleQuote	matchgroup=shQuote start=+"+ matchgroup=shSpecial skip=+\\"+ matchgroup=shQuote end=+"+		contained	contains=@shDblQuoteList,shStringSpecial,@Spell	nextgroup=shSpecialStart
+syn region  shDoubleQuote	matchgroup=shQuote start=+\%(\%(\\\\\)*\\\)\@<!"+ skip=+\\.+ end=+"+			contains=@shDblQuoteList,shStringSpecial,@Spell	nextgroup=shSpecialStart
 syn match   shStringSpecial	"[^[:print:] \t]"			contained
-syn match   shStringSpecial	"[^\\]\zs\%(\\\\\)*\\[\\"'`$()#]"			nextgroup=shComment
-syn match   shSpecialSQ	"[^\\]\zs\%(\\\\\)*\\[\\"'`$()#]"		contained	nextgroup=shBkslshSnglQuote,@shNoZSList
-syn match   shSpecialDQ	"[^\\]\zs\%(\\\\\)*\\[\\"'`$()#]"		contained	nextgroup=shBkslshDblQuote,@shNoZSList
+syn match   shStringSpecial	"[^\\]\zs\%(\\\\\)*\(\\[\\"'`$()#]\)\+"			nextgroup=shComment
+syn match   shSpecialSQ	"[^\\]\zs\%(\\\\\)*\(\\[\\"'`$()#]\)\+"		contained	nextgroup=shBkslshSnglQuote,@shNoZSList
+syn match   shSpecialDQ	"[^\\]\zs\%(\\\\\)*\(\\[\\"'`$()#]\)\+"		contained	nextgroup=shBkslshDblQuote,@shNoZSList
 syn match   shSpecialStart	"\%(\\\\\)*\\[\\"'`$()#]"			contained	nextgroup=shBkslshSnglQuote,shBkslshDblQuote,@shNoZSList
 syn match   shSpecial	"^\%(\\\\\)*\\[\\"'`$()#]"
 syn match   shSpecialNoZS	contained	"\%(\\\\\)*\\[\\"'`$()#]"
@@ -402,6 +405,7 @@ syn match	shQuickComment	contained	"#.*$"
 syn match	shBQComment	contained	"#.\{-}\ze`"	contains=@shCommentGroup
 
 " Here Documents: {{{1
+"  (modified by Felipe Contreras)
 " =========================================
 ShFoldHereDoc syn region shHereDoc matchgroup=shHereDoc01 start="<<\s*\z([^ \t|>]\+\)"		matchgroup=shHereDoc01 end="^\z1\s*$"	contains=@shDblQuoteList
 ShFoldHereDoc syn region shHereDoc matchgroup=shHereDoc02 start="<<-\s*\z([^ \t|>]\+\)"		matchgroup=shHereDoc02 end="^\s*\z1\s*$"	contains=@shDblQuoteList