--- a/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
+++ b/runtime/pack/dist/opt/termdebug/plugin/termdebug.vim
@@ -4,7 +4,7 @@ vim9script
 
 # Author: Bram Moolenaar
 # Copyright: Vim license applies, see ":help license"
-# Last Change: 2024 Jun 03
+# Last Change: 2024 Jun 13
 # Converted to Vim9: Ubaldo Tiberi <ubaldo.tiberi@gmail.com>
 
 # WORK IN PROGRESS - The basics works stable, more to come
@@ -38,44 +38,56 @@ vim9script
 # The communication with gdb uses GDB/MI.  See:
 # https://sourceware.org/gdb/current/onlinedocs/gdb/GDB_002fMI.html
 
-# In case this gets sourced twice.
+def Echoerr(msg: string)
+  echohl ErrorMsg | echom $'[termdebug] {msg}' | echohl None
+enddef
+
+
+# Variables to keep their status among multiple instances of Termdebug
+# Avoid to source the script twice.
 if exists('g:termdebug_loaded')
-  finish
+    Echoerr('Termdebug already loaded.')
+    finish
 endif
 g:termdebug_loaded = true
 
-var way = 'terminal'
-var err = 'no errors'
+# Script variables declaration. These variables are re-initialized at every
+# Termdebug instance
+var way: string
+var err: string
 
-var pc_id = 12
-var asm_id = 13
-var break_id = 14  # breakpoint number is added to this
-var stopped = 1
-var running = 0
+var pc_id: number
+var asm_id: number
+var break_id: number
+var stopped: bool
+var running: bool
 
-var parsing_disasm_msg = 0
-var asm_lines = []
-var asm_addr = ''
+var parsing_disasm_msg: number
+var asm_lines: list<string>
+var asm_addr: string
 
 # These shall be constants but cannot be initialized here
 # They indicate the buffer numbers of the main buffers used
-var gdbbuf = 0
-var varbuf = 0
-var asmbuf = 0
-var promptbuf = 0
+var gdbbufnr: number
+var gdbbufname: string
+var varbufnr: number
+var varbufname: string
+var asmbufnr: number
+var asmbufname: string
+var promptbuf: number
 # This is for the "debugged program" thing
-var ptybuf = 0
-var commbuf = 0
+var ptybufnr: number
+var commbufnr: number
 
-var gdbjob = null_job
-var gdb_channel = null_channel
+var gdbjob: job
+var gdb_channel: channel
 # These changes because they relate to windows
-var pid = 0
-var gdbwin = 0
-var varwin = 0
-var asmwin = 0
-var ptywin = 0
-var sourcewin = 0
+var pid: number
+var gdbwin: number
+var varwin: number
+var asmwin: number
+var ptywin: number
+var sourcewin: number
 
 # Contains breakpoints that have been placed, key is a string with the GDB
 # breakpoint number.
@@ -84,52 +96,112 @@ var sourcewin = 0
 # For a breakpoint "123.4" the id is "123" and subid is "4".
 # Example, when breakpoint "44", "123", "123.1" and "123.2" exist:
 # {'44': {'0': entry}, '123': {'0': entry, '1': entry, '2': entry}}
-var breakpoints = {}
+var breakpoints: dict<any>
 
 # Contains breakpoints by file/lnum.  The key is "fname:lnum".
 # Each entry is a list of breakpoint IDs at that position.
-var breakpoint_locations = {}
-var BreakpointSigns: list<string> = []
-
+var breakpoint_locations: dict<any>
+var BreakpointSigns: list<string>
 
-var evalFromBalloonExpr = 0
-var evalFromBalloonExprResult = ''
-var ignoreEvalError = 0
-var evalexpr = ''
+var evalFromBalloonExpr: bool
+var evalFromBalloonExprResult: string
+var ignoreEvalError: bool
+var evalexpr: string
 # Remember the old value of 'signcolumn' for each buffer that it's set in, so
 # that we can restore the value for all buffers.
-var signcolumn_buflist = [bufnr()]
-var save_columns = 0
+var signcolumn_buflist: list<number>
+var save_columns: number
 
-var allleft = 0
+var allleft: bool
 # This was s:vertical but I cannot use vertical as variable name
-var vvertical = 0
+var vvertical: bool
+
+var winbar_winids: list<number>
 
-var winbar_winids = []
-var plus_map_saved = {}
-var minus_map_saved = {}
-var k_map_saved = {}
-var saved_mousemodel = null_string
+var saved_mousemodel: string
+
+var k_map_saved: dict<any>
+var plus_map_saved: dict<any>
+var minus_map_saved: dict<any>
 
 
-# Need either the +terminal feature or +channel and the prompt buffer.
-# The terminal feature does not work with gdb on win32.
-if has('terminal') && !has('win32')
-  way = 'terminal'
-elseif has('channel') && exists('*prompt_setprompt')
-  way = 'prompt'
-else
-  if has('terminal')
-    err = 'Cannot debug, missing prompt buffer support'
+def InitScriptVariables()
+  if exists('g:termdebug_config') && has_key(g:termdebug_config, 'use_prompt')
+    way = g:termdebug_config['use_prompt'] ? 'prompt' : 'terminal'
+  elseif exists('g:termdebug_use_prompt')
+    way = g:termdebug_use_prompt
+  elseif has('terminal') && !has('win32')
+    way = 'terminal'
   else
-    err = 'Cannot debug, +channel feature is not supported'
+    way = 'prompt'
   endif
-  command -nargs=* -complete=file -bang Termdebug echoerr err
-  command -nargs=+ -complete=file -bang TermdebugCommand echoerr err
-  finish
-endif
+  err = ''
+
+  pc_id = 12
+  asm_id = 13
+  break_id = 14  # breakpoint number is added to this
+  stopped = true
+  running = false
+
+  parsing_disasm_msg = 0
+  asm_lines = []
+  asm_addr = ''
+
+  # They indicate the buffer numbers of the main buffers used
+  gdbbufnr = 0
+  gdbbufname = 'gdb'
+  varbufnr = 0
+  varbufname = 'Termdebug-variables-listing'
+  asmbufnr = 0
+  asmbufname = 'Termdebug-asm-listing'
+  promptbuf = 0
+  # This is for the "debugged program" thing
+  ptybufnr = 0
+  commbufnr = 0
+
+  gdbjob = null_job
+  gdb_channel = null_channel
+  # These changes because they relate to windows
+  pid = 0
+  gdbwin = 0
+  varwin = 0
+  asmwin = 0
+  ptywin = 0
+  sourcewin = 0
 
+  # Contains breakpoints that have been placed, key is a string with the GDB
+  # breakpoint number.
+  # Each entry is a dict, containing the sub-breakpoints.  Key is the subid.
+  # For a breakpoint that is just a number the subid is zero.
+  # For a breakpoint "123.4" the id is "123" and subid is "4".
+  # Example, when breakpoint "44", "123", "123.1" and "123.2" exist:
+  # {'44': {'0': entry}, '123': {'0': entry, '1': entry, '2': entry}}
+  breakpoints = {}
 
+  # Contains breakpoints by file/lnum.  The key is "fname:lnum".
+  # Each entry is a list of breakpoint IDs at that position.
+  breakpoint_locations = {}
+  BreakpointSigns = []
+
+  evalFromBalloonExpr = false
+  evalFromBalloonExprResult = ''
+  ignoreEvalError = false
+  evalexpr = ''
+  # Remember the old value of 'signcolumn' for each buffer that it's set in, so
+  # that we can restore the value for all buffers.
+  signcolumn_buflist = [bufnr()]
+  save_columns = 0
+
+  winbar_winids = []
+
+  k_map_saved = {}
+  plus_map_saved = {}
+  minus_map_saved = {}
+
+  if has('menu')
+    saved_mousemodel = null_string
+  endif
+enddef
 # The command that starts debugging, e.g. ":Termdebug vim".
 # To end type "quit" in the gdb window.
 command -nargs=* -complete=file -bang Termdebug StartDebug(<bang>0, <f-args>)
@@ -182,11 +254,8 @@ def GetCommand(): list<string>
   return type(cmd) == v:t_list ? copy(cmd) : [cmd]
 enddef
 
-def Echoerr(msg: string)
-  echohl ErrorMsg | echom $'[termdebug] {msg}' | echohl None
-enddef
-
 def StartDebug(bang: bool, ...gdb_args: list<string>)
+  InitScriptVariables()
   # First argument is the command to debug, second core file or process ID.
   StartDebug_internal({gdb_args: gdb_args, bang: bang})
 enddef
@@ -227,24 +296,11 @@ def StartDebug_internal(dict: dict<any>)
       &columns = wide
       # If we make the Vim window wider, use the whole left half for the debug
       # windows.
-      allleft = 1
+      allleft = true
     endif
-    vvertical = 1
+    vvertical = true
   else
-    vvertical = 0
-  endif
-
-  # Override using a terminal window by setting g:termdebug_use_prompt to 1.
-  var use_prompt = 0
-  if exists('g:termdebug_config')
-    use_prompt = get(g:termdebug_config, 'use_prompt', 0)
-  elseif exists('g:termdebug_use_prompt')
-    use_prompt = g:termdebug_use_prompt
-  endif
-  if has('terminal') && !has('win32') && !use_prompt
-    way = 'terminal'
-  else
-    way = 'prompt'
+    vvertical = false
   endif
 
   if way == 'prompt'
@@ -272,45 +328,42 @@ enddef
 
 # Use when debugger didn't start or ended.
 def CloseBuffers()
-  exe $'bwipe! {ptybuf}'
-  exe $'bwipe! {commbuf}'
-  if asmbuf > 0 && bufexists(asmbuf)
-    exe $'bwipe! {asmbuf}'
+  exe $'bwipe! {ptybufnr}'
+  exe $'bwipe! {commbufnr}'
+  if asmbufnr > 0 && bufexists(asmbufnr)
+    exe $'bwipe! {asmbufnr}'
   endif
-  if varbuf > 0 && bufexists(varbuf)
-    exe $'bwipe! {varbuf}'
+  if varbufnr > 0 && bufexists(varbufnr)
+    exe $'bwipe! {varbufnr}'
   endif
   running = 0
   gdbwin = 0
 enddef
 
 # IsGdbRunning(): bool may be a better name?
-def CheckGdbRunning(): string
-  var gdbproc = term_getjob(gdbbuf)
-  var gdbproc_status = 'unknown'
-  if type(gdbproc) == v:t_job
-    gdbproc_status = job_status(gdbproc)
-  endif
-  if gdbproc == v:null || gdbproc_status !=# 'run'
+def IsGdbStarted(): bool
+  var gdbproc_status = job_status(term_getjob(gdbbufnr))
+  if gdbproc_status !=# 'run'
     var cmd_name = string(GetCommand()[0])
     Echoerr($'{cmd_name} exited unexpectedly')
     CloseBuffers()
-    return ''
+    return false
   endif
-  return 'ok'
+  return true
 enddef
 
 # Open a terminal window without a job, to run the debugged program in.
 def StartDebug_term(dict: dict<any>)
-  ptybuf = term_start('NONE', {
+  ptybufnr = term_start('NONE', {
     term_name: 'debugged program',
     vertical: vvertical})
-  if ptybuf == 0
+  if ptybufnr == 0
     Echoerr('Failed to open the program terminal window')
     return
   endif
-  var pty = job_info(term_getjob(ptybuf))['tty_out']
+  var pty = job_info(term_getjob(ptybufnr))['tty_out']
   ptywin = win_getid()
+
   if vvertical
     # Assuming the source code window will get a signcolumn, use two more
     # columns for that, thus one less for the terminal window.
@@ -322,23 +375,26 @@ def StartDebug_term(dict: dict<any>)
   endif
 
   # Create a hidden terminal window to communicate with gdb
-  commbuf = term_start('NONE', {
+  commbufnr = term_start('NONE', {
     term_name: 'gdb communication',
     out_cb: function('CommOutput'),
     hidden: 1
   })
-  if commbuf == 0
+  if commbufnr == 0
     Echoerr('Failed to open the communication terminal window')
-    exe $'bwipe! {ptybuf}'
+    exe $'bwipe! {ptybufnr}'
     return
   endif
-  var commpty = job_info(term_getjob(commbuf))['tty_out']
+  var commpty = job_info(term_getjob(commbufnr))['tty_out']
 
+  # Start the gdb buffer
   var gdb_args = get(dict, 'gdb_args', [])
   var proc_args = get(dict, 'proc_args', [])
 
   var gdb_cmd = GetCommand()
 
+  gdbbufname = gdb_cmd[0]
+
   if exists('g:termdebug_config') && has_key(g:termdebug_config, 'command_add_args')
     gdb_cmd = g:termdebug_config.command_add_args(gdb_cmd, pty)
   else
@@ -365,11 +421,11 @@ def StartDebug_term(dict: dict<any>)
   gdb_cmd += gdb_args
 
   ch_log($'executing "{join(gdb_cmd)}"')
-  gdbbuf = term_start(gdb_cmd, {
-    term_name: 'gdb',
-    term_finish: 'close',
-  })
-  if gdbbuf == 0
+  gdbbufnr = term_start(gdb_cmd, {
+        term_name: gdbbufname,
+        term_finish: 'close',
+        })
+  if gdbbufnr == 0
     Echoerr('Failed to open the gdb terminal window')
     CloseBuffers()
     return
@@ -380,14 +436,14 @@ def StartDebug_term(dict: dict<any>)
   var counter = 0
   var counter_max = 300
   var success = false
-  while success == false && counter < counter_max
-    if CheckGdbRunning() != 'ok'
-      # Failure. If NOK just return.
+  while !success && counter < counter_max
+    if !IsGdbStarted()
+      CloseBuffers()
       return
     endif
 
     for lnum in range(1, 200)
-      if term_getline(gdbbuf, lnum) =~ 'startupdone'
+      if term_getline(gdbbufnr, lnum) =~ 'startupdone'
         success = true
       endif
     endfor
@@ -397,7 +453,7 @@ def StartDebug_term(dict: dict<any>)
     sleep 10m
   endwhile
 
-  if success == false
+  if !success
     Echoerr('Failed to startup the gdb program.')
     CloseBuffers()
     return
@@ -406,30 +462,30 @@ def StartDebug_term(dict: dict<any>)
   # ---- gdb started. Next, let's set the MI interface. ---
   # Set arguments to be run.
   if len(proc_args)
-    term_sendkeys(gdbbuf, $"server set args {join(proc_args)}\r")
+    term_sendkeys(gdbbufnr, $"server set args {join(proc_args)}\r")
   endif
 
   # Connect gdb to the communication pty, using the GDB/MI interface.
   # Prefix "server" to avoid adding this to the history.
-  term_sendkeys(gdbbuf, $"server new-ui mi {commpty}\r")
+  term_sendkeys(gdbbufnr, $"server new-ui mi {commpty}\r")
 
   # Wait for the response to show up, users may not notice the error and wonder
   # why the debugger doesn't work.
   counter = 0
   counter_max = 300
   success = false
-  while success == false && counter < counter_max
-    if CheckGdbRunning() != 'ok'
+  while !success && counter < counter_max
+    if !IsGdbStarted()
       return
     endif
 
     var response = ''
     for lnum in range(1, 200)
-      var line1 = term_getline(gdbbuf, lnum)
-      var line2 = term_getline(gdbbuf, lnum + 1)
+      var line1 = term_getline(gdbbufnr, lnum)
+      var line2 = term_getline(gdbbufnr, lnum + 1)
       if line1 =~ 'new-ui mi '
         # response can be in the same line or the next line
-        response = line1 .. line2
+        response = $"{line1}{line2}"
         if response =~ 'Undefined command'
           Echoerr('Sorry, your gdb is too old, gdb 7.12 is required')
           # CHECKME: possibly send a "server show version" here
@@ -452,12 +508,12 @@ def StartDebug_term(dict: dict<any>)
     sleep 10m
   endwhile
 
-  if success == false
+  if !success
     Echoerr('Cannot check if your gdb works, continuing anyway')
     return
   endif
 
-  job_setoptions(term_getjob(gdbbuf), {exit_cb: function('EndTermDebug')})
+  job_setoptions(term_getjob(gdbbufnr), {exit_cb: function('EndTermDebug')})
 
   # Set the filetype, this can be used to add mappings.
   set filetype=termdebug
@@ -531,23 +587,24 @@ def StartDebug_prompt(dict: dict<any>)
   set modified
   gdb_channel = job_getchannel(gdbjob)
 
-  ptybuf = 0
+  ptybufnr = 0
   if has('win32')
     # MS-Windows: run in a new console window for maximum compatibility
     SendCommand('set new-console on')
   elseif has('terminal')
     # Unix: Run the debugged program in a terminal window.  Open it below the
     # gdb window.
-    belowright ptybuf = term_start('NONE', {
+    belowright ptybufnr = term_start('NONE', {
       term_name: 'debugged program',
+      vertical: vvertical
     })
-    if ptybuf == 0
+    if ptybufnr == 0
       Echoerr('Failed to open the program terminal window')
       job_stop(gdbjob)
       return
     endif
     ptywin = win_getid()
-    var pty = job_info(term_getjob(ptybuf))['tty_out']
+    var pty = job_info(term_getjob(ptybufnr))['tty_out']
     SendCommand($'tty {pty}')
 
     # Since GDB runs in a prompt window, the environment has not been set to
@@ -615,7 +672,7 @@ def SendCommand(cmd: string)
   if way == 'prompt'
     ch_sendraw(gdb_channel, $"{cmd}\n")
   else
-    term_sendkeys(commbuf, $"{cmd}\r")
+    term_sendkeys(commbufnr, $"{cmd}\r")
   endif
 enddef
 
@@ -652,7 +709,7 @@ def TermDebugSendCommand(cmd: string)
       sleep 10m
     endif
     # TODO: should we prepend CTRL-U to clear the command?
-    term_sendkeys(gdbbuf, $"{cmd}\r")
+    term_sendkeys(gdbbufnr, $"{cmd}\r")
     if do_continue
       ContinueCommand()
     endif
@@ -665,7 +722,7 @@ enddef
 def SendResumingCommand(cmd: string)
   if stopped
     # reset stopped here, it may take a bit of time before we get a response
-    stopped = 0
+    stopped = false
     ch_log('assume that program is running after this command')
     SendCommand(cmd)
   else
@@ -715,9 +772,9 @@ def GdbOutCallback(channel: channel, tex
   var decoded_text = ''
   if text =~ '^\^error,msg='
     decoded_text = DecodeMessage(text[11 : ], false)
-    if exists('evalexpr') && decoded_text =~ 'A syntax error in expression, near\|No symbol .* in current context'
+    if !empty(evalexpr) && decoded_text =~ 'A syntax error in expression, near\|No symbol .* in current context'
       # Silently drop evaluation errors.
-      evalexpr = null_string
+      evalexpr = ''
       return
     endif
   elseif text[0] == '~'
@@ -739,9 +796,9 @@ enddef
 
 # Decode a message from gdb.  "quotedText" starts with a ", return the text up
 # to the next unescaped ", unescaping characters:
-# - remove line breaks (unless "literal" is v:true)
+# - remove line breaks (unless "literal" is true)
 # - change \" to "
-# - change \\t to \t (unless "literal" is v:true)
+# - change \\t to \t (unless "literal" is true)
 # - change \0xhh to \xhh (disabled for now)
 # - change \ooo to octal
 # - change \\ to \
@@ -751,19 +808,20 @@ def DecodeMessage(quotedText: string, li
     return ''
   endif
   var msg = quotedText
-        \ ->substitute('^"\|[^\\]\zs".*', '', 'g')
-        \ ->substitute('\\"', '"', 'g')
+        ->substitute('^"\|[^\\]\zs".*', '', 'g')
+        ->substitute('\\"', '"', 'g')
         #\ multi-byte characters arrive in octal form
         #\ NULL-values must be kept encoded as those break the string otherwise
-        \ ->substitute('\\000', NullRepl, 'g')
-        \ ->substitute('\\\(\o\o\o\)', (m) => nr2char(str2nr(m[1], 8)), 'g')
+        ->substitute('\\000', NullRepl, 'g')
+        ->substitute('\\\(\o\o\o\)', (m) => nr2char(str2nr(m[1], 8)), 'g')
+        # You could also  use ->substitute('\\\\\(\o\o\o\)', '\=nr2char(str2nr(submatch(1), 8))', "g")
         #\ Note: GDB docs also mention hex encodings - the translations below work
         #\       but we keep them out for performance-reasons until we actually see
         #\       those in mi-returns
         #\ \ ->substitute('\\0x\(\x\x\)', {-> eval('"\x' .. submatch(1) .. '"')}, 'g')
         #\ \ ->substitute('\\0x00', NullRepl, 'g')
-        \ ->substitute('\\\\', '\', 'g')
-        \ ->substitute(NullRepl, '\\000', 'g')
+        ->substitute('\\\\', '\', 'g')
+        ->substitute(NullRepl, '\\000', 'g')
   if !literal
     return msg
       ->substitute('\\t', "\t", 'g')
@@ -805,8 +863,8 @@ def EndTermDebug(job: any, status: any)
     doauto <nomodeline> User TermdebugStopPre
   endif
 
-  if bufexists(commbuf)
-    exe $'bwipe! {commbuf}'
+  if commbufnr > 0 && bufexists(commbufnr)
+    exe $'bwipe! {commbufnr}'
   endif
   gdbwin = 0
   EndDebugCommon()
@@ -815,16 +873,16 @@ enddef
 def EndDebugCommon()
   var curwinid = win_getid()
 
-  if bufexists(ptybuf)
-    exe $'bwipe! {ptybuf}'
+  if ptybufnr > 0 && bufexists(ptybufnr)
+    exe $'bwipe! {ptybufnr}'
   endif
-  if bufexists(asmbuf)
-    exe $'bwipe! {asmbuf}'
+  if asmbufnr > 0 && bufexists(asmbufnr)
+    exe $'bwipe! {asmbufnr}'
   endif
-  if bufexists(varbuf)
-    exe $'bwipe! {varbuf}'
+  if varbufnr > 0 && bufexists(varbufnr)
+    exe $'bwipe! {varbufnr}'
   endif
-  running = 0
+  running = false
 
   # Restore 'signcolumn' in all buffers for which it was set.
   win_gotoid(sourcewin)
@@ -932,11 +990,11 @@ def HandleDisasmMsg(msg: string)
     endif
   elseif msg !~ '^&"disassemble'
     var value = substitute(msg, '^\~\"[ ]*', '', '')
-    value = substitute(value, '^=>[ ]*', '', '')
-    value = substitute(value, '\\n\"\r$', '', '')
-    value = substitute(value, '\\n\"$', '', '')
-    value = substitute(value, '\r', '', '')
-    value = substitute(value, '\\t', ' ', 'g')
+     ->substitute('^=>[ ]*', '', '')
+     ->substitute('\\n\"\r$', '', '')
+     ->substitute('\\n\"$', '', '')
+     ->substitute('\r', '', '')
+     ->substitute('\\t', ' ', 'g')
 
     if value != '' || !empty(asm_lines)
       add(asm_lines, value)
@@ -1248,7 +1306,7 @@ def Until(at: string)
 
   if stopped
     # reset stopped here, it may take a bit of time before we get a response
-    stopped = 0
+    stopped = false
     ch_log('assume that program is running after this command')
 
     # Use the fname:lnum format
@@ -1379,8 +1437,8 @@ enddef
 # :Evaluate - evaluate what is specified / under the cursor
 def Evaluate(range: number, arg: string)
   var expr = GetEvaluationExpression(range, arg)
-  #echom $"expr: {expr}"
-  ignoreEvalError = 0
+  echom $"expr: {expr}"
+  ignoreEvalError = false
   SendEval(expr)
 enddef
 
@@ -1435,21 +1493,20 @@ enddef
 
 def HandleEvaluate(msg: string)
   var value = msg
-        \ ->substitute('.*value="\(.*\)"', '\1', '')
-        \ ->substitute('\\"', '"', 'g')
-        \ ->substitute('\\\\', '\\', 'g')
+        ->substitute('.*value="\(.*\)"', '\1', '')
+        ->substitute('\\"', '"', 'g')
+        ->substitute('\\\\', '\\', 'g')
         #\ multi-byte characters arrive in octal form, replace everything but NULL values
-        \ ->substitute('\\000', NullRepl, 'g')
-        # \ ->substitute('\\\o\o\o', {-> eval('"' .. submatch(0) .. '"')}, 'g')
-        \ ->substitute('\\\(\o\o\o\)', (m) => nr2char(str2nr(m[1], 8)), 'g')
+        ->substitute('\\000', NullRepl, 'g')
+        ->substitute('\\\(\o\o\o\)', (m) => nr2char(str2nr(m[1], 8)), 'g')
         #\ Note: GDB docs also mention hex encodings - the translations below work
         #\       but we keep them out for performance-reasons until we actually see
         #\       those in mi-returns
         #\ ->substitute('\\0x00', NullRep, 'g')
         #\ ->substitute('\\0x\(\x\x\)', {-> eval('"\x' .. submatch(1) .. '"')}, 'g')
-        \ ->substitute(NullRepl, '\\000', 'g')
+        ->substitute(NullRepl, '\\000', 'g')
   if evalFromBalloonExpr
-    if evalFromBalloonExprResult == ''
+    if empty(evalFromBalloonExprResult)
       evalFromBalloonExprResult = $'{evalexpr}: {value}'
     else
       evalFromBalloonExprResult ..= $' = {value}'
@@ -1461,10 +1518,10 @@ def HandleEvaluate(msg: string)
 
   if evalexpr[0] != '*' && value =~ '^0x' && value != '0x0' && value !~ '"$'
     # Looks like a pointer, also display what it points to.
-    ignoreEvalError = 1
+    ignoreEvalError = true
     SendEval($'*{evalexpr}')
   else
-    evalFromBalloonExpr = 0
+    evalFromBalloonExpr = false
   endif
 enddef
 
@@ -1480,9 +1537,9 @@ def TermDebugBalloonExpr(): string
     # mouse triggers a balloon.
     return ''
   endif
-  evalFromBalloonExpr = 1
+  evalFromBalloonExpr = true
   evalFromBalloonExprResult = ''
-  ignoreEvalError = 1
+  ignoreEvalError = true
   var expr = CleanupExpr(v:beval_text)
   SendEval(expr)
   return ''
@@ -1492,8 +1549,8 @@ enddef
 def HandleError(msg: string)
   if ignoreEvalError
     # Result of SendEval() failed, ignore.
-    ignoreEvalError = 0
-    evalFromBalloonExpr = 0
+    ignoreEvalError = false
+    evalFromBalloonExpr = true
     return
   endif
   var msgVal = substitute(msg, '.*msg="\(.*\)"', '\1', '')
@@ -1554,11 +1611,11 @@ def GotoAsmwinOrCreateIt()
     setlocal signcolumn=no
     setlocal modifiable
 
-    if asmbuf > 0 && bufexists(asmbuf)
-      exe $'buffer {asmbuf}'
+    if asmbufnr > 0 && bufexists(asmbufnr)
+      exe $'buffer {asmbufnr}'
     elseif empty(glob('Termdebug-asm-listing'))
       silent file Termdebug-asm-listing
-      asmbuf = bufnr('Termdebug-asm-listing')
+      asmbufnr = bufnr('Termdebug-asm-listing')
     else
       Echoerr("You have a file/folder named 'Termdebug-asm-listing'. " ..
               "Please exit and rename it because Termdebug may not work " ..
@@ -1628,11 +1685,11 @@ def GotoVariableswinOrCreateIt()
     setlocal signcolumn=no
     setlocal modifiable
 
-    if varbuf > 0 && bufexists(varbuf)
-      exe $'buffer {varbuf}'
+    if varbufnr > 0 && bufexists(varbufnr)
+      exe $'buffer {varbufnr}'
     elseif empty(glob('Termdebug-variables-listing'))
       silent file Termdebug-variables-listing
-      varbuf = bufnr('Termdebug-variables-listing')
+      varbufnr = bufnr('Termdebug-variables-listing')
     else
       Echoerr("You have a file/folder named 'Termdebug-variables-listing'. " ..
               "Please exit and rename it because Termdebug may not work " ..
@@ -1658,12 +1715,12 @@ def HandleCursor(msg: string)
     ch_log('program stopped')
     stopped = 1
     if msg =~ '^\*stopped,reason="exited-normally"'
-      running = 0
+      running = false
     endif
   elseif msg =~ '^\*running'
     ch_log('program running')
-    stopped = 0
-    running = 1
+    stopped = false
+    running = true
   endif
 
   var fname = ''
@@ -1692,7 +1749,7 @@ def HandleCursor(msg: string)
     endif
   endif
 
-  if running && stopped && bufwinnr('Termdebug-variables-listing') != -1
+  if running && stopped && bufwinnr(varbufname) != -1
     SendCommand('-stack-list-variables 2')
   endif
 
@@ -1709,13 +1766,13 @@ def HandleCursor(msg: string)
           au SwapExists * echohl WarningMsg
             | echo 'Warning: file is being edited elsewhere'
             | echohl None
-            | let v:swapchoice = 'o'
+            | v:swapchoice = 'o'
         augroup END
         if &modified
           # TODO: find existing window
           exe $'split {fnameescape(fname)}'
           sourcewin = win_getid()
-          call InstallWinbar(0)
+          InstallWinbar(0)
         else
           exe $'edit {fnameescape(fname)}'
         endif

--- a/src/testdir/test_termdebug.vim
+++ b/src/testdir/test_termdebug.vim
@@ -338,5 +338,16 @@ func Test_termdebug_bufnames()
   unlet g:termdebug_config
 endfunc
 
+function Test_termdebug_save_restore_variables()
+  let &mousemodel=''
+  Termdebug
+  call WaitForAssert({-> assert_equal(3, winnr('$'))})
+  call WaitForAssert({-> assert_match(&mousemodel, 'popup_setpos')})
+  wincmd t
+  quit!
+  call WaitForAssert({-> assert_equal(1, winnr('$'))})
+  call WaitForAssert({-> assert_true(empty(&mousemodel))})
+endfunction
+
 
 " vim: shiftwidth=2 sts=2 expandtab

--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@ static char *(features[]) =
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    482,
+/**/
     481,
 /**/
     480,