Code cleanup.

Of note:
* io.save_all_files() does not visit each buffer to save anymore. An unintended
  side-effect was checking for outside modification (but only if the file itself
  was modified), so outside changes will always be saved over now.
* The menu clicked handler uses assert_type(), so the 'Unknown command'
  localization is no longer needed.
* When printing to a new buffer type would split the view, use an existing split
  view when possible.
* Prefer 'goto continue' construct in loops over nested 'if's.
* Fixed clearing of ui.find.replace_entry_text on reset in the GUI version.
* Fixed lack of statusbar updating when setting options like buffer EOL mode,
  indentation, and encoding.
* Renamed internal new_snippet() to new() and put it in the snippet metatable.

19 files changed, 151 insertions, 211 deletions

diff --git a/core/args.lua b/core/args.lua
index 3d249c9a..af605d36 100644
--- a/core/args.lua
+++ b/core/args.lua
@@ -11,7 +11,7 @@ module('args')]]
 
 events.ARG_NONE = 'arg_none'
 
--- Contains registered command line options.
+-- Map of registered command line options.
 -- @class table
 -- @name options
 local options = {}
@@ -44,6 +44,8 @@ end
 -- Emits an `ARG_NONE` event when no arguments are present unless
 -- *no_emit_arg_none* is `true`.
 -- @param arg Argument table.
+-- @param no_emit_arg_none When `true`, do not emit `ARG_NONE` when no arguments
+--   are present. The default value is `false`.
 -- @see register
 -- @see _G.events
 local function process(arg, no_emit_arg_none)
@@ -135,7 +137,7 @@ M.register('-t', '--test', 1, function(patterns)
     local arg = {}
     for patt in (patterns or ''):gmatch('[^,]+') do arg[#arg + 1] = patt end
     local env = setmetatable({arg = arg}, {__index = _G})
-    assert(loadfile(_HOME..'/test/test.lua', 't', env))()
+    assert(loadfile(_HOME .. '/test/test.lua', 't', env))()
   end)
 end, 'Runs unit tests indicated by comma-separated list of patterns (or all)')
 
diff --git a/core/assert.lua b/core/assert.lua
index baa08d5b..80e50a6e 100644
--- a/core/assert.lua
+++ b/core/assert.lua
@@ -31,7 +31,7 @@ end
 -- This is intended to be used with API function arguments so users receive more
 -- helpful error messages.
 -- @param v Value to assert the type of.
--- @param expected_type String type to assert. It may be a punctuation-delimited
+-- @param expected_type String type to assert. It may be a non-letter-delimited
 --   list of type options.
 -- @param narg The positional argument number *v* is associated with. This is
 --   not required to be a number.
diff --git a/core/events.lua b/core/events.lua
index 7282172d..1c146145 100644
--- a/core/events.lua
+++ b/core/events.lua
@@ -391,11 +391,10 @@ end
 
 -- Handles Scintilla notifications.
 M.connect('SCN', function(notification)
-  local f = _SCINTILLA.events[notification.code]
-  if not f then return end
+  local iface = _SCINTILLA.events[notification.code]
   local args = {}
-  for i = 2, #f do args[i - 1] = notification[f[i]] end
-  return M.emit(f[1], table.unpack(args))
+  for i = 2, #iface do args[i - 1] = notification[iface[i]] end
+  return M.emit(iface[1], table.unpack(args))
 end)
 
 -- Set event constants.
diff --git a/core/file_io.lua b/core/file_io.lua
index 39d005b2..0426083a 100644
--- a/core/file_io.lua
+++ b/core/file_io.lua
@@ -42,13 +42,8 @@
 module('io')]]
 
 -- Events.
-local events, events_connect = events, events.connect
-events.FILE_OPENED = 'file_opened'
-events.FILE_BEFORE_RELOAD = 'file_before_reload'
-events.FILE_AFTER_RELOAD = 'file_after_reload'
-events.FILE_BEFORE_SAVE = 'file_before_save'
-events.FILE_AFTER_SAVE = 'file_after_save'
-events.FILE_CHANGED = 'file_changed'
+local file_io_events = {'file_opened','file_before_reload','file_after_reload','file_before_save','file_after_save','file_changed'}
+for _, v in ipairs(file_io_events) do events[v:upper()] = v end
 
 io.quick_open_max = 1000
 
@@ -137,7 +132,7 @@ function io.open_file(filenames, encodings)
     buffer.code_page = buffer.encoding and buffer.CP_UTF8 or 0
     -- Detect EOL mode.
     local s, e = text:find('\r?\n')
-    if s then buffer.eol_mode = buffer[s < e and 'EOL_CRLF' or 'EOL_LF'] end
+    if s then buffer.eol_mode = buffer[s ~= e and 'EOL_CRLF' or 'EOL_LF'] end
     -- Insert buffer text and set properties.
     buffer:append_text(text)
     buffer:empty_undo_buffer()
@@ -225,22 +220,17 @@ end
 -- @see buffer.save
 -- @name save_all_files
 function io.save_all_files()
-  local current_buffer = buffer
   for _, buffer in ipairs(_BUFFERS) do
-    if buffer.filename and buffer.modify then
-      view:goto_buffer(buffer)
-      buffer:save()
-    end
+    if buffer.filename and buffer.modify then buffer:save() end
   end
-  view:goto_buffer(current_buffer)
 end
 
 -- LuaDoc is in core/.buffer.luadoc.
 local function close(buffer, force)
   if not buffer then buffer = _G.buffer end
-  local filename = buffer.filename or buffer._type or _L['Untitled']
-  if buffer.filename then filename = filename:iconv('UTF-8', _CHARSET) end
   if buffer.modify and not force then
+    local filename = buffer.filename or buffer._type or _L['Untitled']
+    if buffer.filename then filename = filename:iconv('UTF-8', _CHARSET) end
     local button = ui.dialogs.msgbox{
       title = _L['Close without saving?'],
       text = _L['There are unsaved changes in'], informative_text = filename,
@@ -262,15 +252,12 @@ end
 -- @see buffer.close
 -- @name close_all_buffers
 function io.close_all_buffers()
-  while #_BUFFERS > 1 do
-    view:goto_buffer(_BUFFERS[#_BUFFERS])
-    if not buffer:close() then return nil end -- do not propagate key command
-  end
+  while #_BUFFERS > 1 do if not buffer:close() then return nil end end
   return buffer:close() -- the last one
 end
 
 -- Sets buffer io methods and the default buffer encoding.
-events_connect(events.BUFFER_NEW, function()
+events.connect(events.BUFFER_NEW, function()
   buffer.reload = reload
   buffer.set_encoding, buffer.encoding = set_encoding, 'UTF-8'
   buffer.save, buffer.save_as, buffer.close = save, save_as, close
@@ -286,20 +273,19 @@ io._reload, io._save, io._save_as, io._close = reload, save, save_as, close
 local function update_modified_file()
   if not buffer.filename then return end
   local mod_time = lfs.attributes(buffer.filename, 'modification')
-  if not mod_time or not buffer.mod_time then return end
-  if buffer.mod_time < mod_time then
+  if mod_time and buffer.mod_time and buffer.mod_time < mod_time then
     buffer.mod_time = mod_time
     events.emit(events.FILE_CHANGED, buffer.filename)
   end
 end
-events_connect(events.BUFFER_AFTER_SWITCH, update_modified_file)
-events_connect(events.VIEW_AFTER_SWITCH, update_modified_file)
-events_connect(events.FOCUS, update_modified_file)
-events_connect(events.RESUME, update_modified_file)
+events.connect(events.BUFFER_AFTER_SWITCH, update_modified_file)
+events.connect(events.VIEW_AFTER_SWITCH, update_modified_file)
+events.connect(events.FOCUS, update_modified_file)
+events.connect(events.RESUME, update_modified_file)
 
 -- Prompts the user to reload the current file if it has been externally
 -- modified.
-events_connect(events.FILE_CHANGED, function(filename)
+events.connect(events.FILE_CHANGED, function(filename)
   local button = ui.dialogs.msgbox{
     title = _L['Reload?'], text = _L['Reload modified file?'],
     informative_text = string.format(
@@ -312,12 +298,10 @@ events_connect(events.FILE_CHANGED, function(filename)
 end)
 
 -- Closes the initial "Untitled" buffer when another buffer is opened.
-events_connect(events.FILE_OPENED, function()
-  local buf = _BUFFERS[1]
-  if #_BUFFERS == 2 and not (buf.filename or buf._type or buf.modify) then
-    view:goto_buffer(_BUFFERS[1])
-    buffer:close()
-  end
+events.connect(events.FILE_OPENED, function()
+  if #_BUFFERS > 2 then return end
+  local first = _BUFFERS[1]
+  if not (first.filename or first._type or first.modify) then first:close() end
 end)
 
 ---
@@ -392,8 +376,8 @@ io.quick_open_filters = {}
 --   search. The default value is the current project's root directory, if
 --   available.
 -- @param filter Optional filter for files and directories to include and/or
---   exclude. The default value is `lfs.default_filter` unless *paths* is a
---   string and a filter for it is defined in `io.quick_open_filters`.
+--   exclude. The default value is `lfs.default_filter` unless a filter for
+--   *paths* is defined in `io.quick_open_filters`.
 -- @param opts Optional table of additional options for
 --   `ui.dialogs.filteredlist()`.
 -- @usage io.quick_open(buffer.filename:match('^(.+)[/\\]')) -- list all files
@@ -412,15 +396,13 @@ function io.quick_open(paths, filter, opts)
     paths = io.get_project_root()
     if not paths then return end
   end
-  if type(paths) == 'string' then
-    if not filter then filter = io.quick_open_filters[paths] end
-    paths = {paths}
+  if not assert_type(filter, 'string/table/nil', 2) then
+    filter = io.quick_open_filters[paths] or lfs.default_filter
   end
-  assert_type(filter, 'string/table/nil', 2)
   assert_type(opts, 'table/nil', 3)
   local utf8_list = {}
-  for i = 1, #paths do
-    for filename in lfs.walk(paths[i], filter or lfs.default_filter) do
+  for _, path in ipairs(type(paths) == 'table' and paths or {paths}) do
+    for filename in lfs.walk(path, filter) do
       if #utf8_list >= io.quick_open_max then break end
       utf8_list[#utf8_list + 1] = filename:iconv('UTF-8', _CHARSET)
     end
diff --git a/core/init.lua b/core/init.lua
index f71cd6be..e2674e48 100644
--- a/core/init.lua
+++ b/core/init.lua
@@ -44,22 +44,20 @@ end
 -- argument.
 -- Documentation is in core/.buffer.luadoc.
 local function text_range(buffer, start_pos, end_pos)
-  assert_type(start_pos, 'number', 2)
-  assert_type(end_pos, 'number', 3)
   local target_start, target_end = buffer.target_start, buffer.target_end
-  if start_pos < 1 then start_pos = 1 end
-  if end_pos > buffer.length + 1 then end_pos = buffer.length + 1 end
-  buffer:set_target_range(start_pos, end_pos)
+  buffer:set_target_range(
+    math.max(1, assert_type(start_pos, 'number', 2)),
+    math.min(assert_type(end_pos, 'number', 3), buffer.length + 1))
   local text = buffer.target_text
   buffer:set_target_range(target_start, target_end) -- restore
   return text
 end
 
+local GETNAMEDSTYLE = _SCINTILLA.properties.named_styles[1]
 -- Documentation is in core/.buffer.luadoc.
 local function style_of_name(buffer, style_name)
-  assert_type(style_name, 'string', 2)
-  local GETNAMEDSTYLE = _SCINTILLA.properties.named_styles[1]
-  return buffer:private_lexer_call(GETNAMEDSTYLE, style_name)
+  return buffer:private_lexer_call(
+    GETNAMEDSTYLE, assert_type(style_name, 'string', 2))
 end
 
 events.connect(events.BUFFER_NEW, function()
diff --git a/core/keys.lua b/core/keys.lua
index ac9523ab..2d4d8781 100644
--- a/core/keys.lua
+++ b/core/keys.lua
@@ -112,8 +112,8 @@ local M = {}
 --   The default value is `nil`.
 module('keys')]]
 
-local CTRL, ALT, SHIFT = 'ctrl+', not CURSES and 'alt+' or 'meta+', 'shift+'
-local CMD = 'cmd+'
+local CTRL, ALT, CMD, SHIFT = 'ctrl+', 'alt+', 'cmd+', 'shift+'
+if CURSES then ALT = 'meta+' end
 M.CLEAR = 'esc'
 
 ---
@@ -151,7 +151,7 @@ local INVALID, PROPAGATE, CHAIN, HALT = -1, 0, 1, 2
 -- Error handler for key commands that simply emits the error. This is needed
 -- so `key_command()` can return `HALT` instead of never returning due to the
 -- error.
-local function key_error(e) events.emit(events.ERROR, e) end
+local function key_error(errmsg) events.emit(events.ERROR, errmsg) end
 
 -- Runs a key command associated with the current keychain.
 -- @param prefix Optional prefix name for mode/lexer-specific commands.
@@ -171,19 +171,11 @@ local function key_command(prefix)
   return select(2, xpcall(key, key_error)) == false and PROPAGATE or HALT
 end
 
--- Handles Textadept keypresses.
--- It is called every time a key is pressed, and based on a mode or lexer,
--- executes a command. The command is looked up in the `_G.keys` table.
--- @param code The keycode.
--- @param shift Whether or not the Shift modifier is pressed.
--- @param control Whether or not the Control modifier is pressed.
--- @param alt Whether or not the Alt/option modifier is pressed.
--- @param cmd Whether or not the Command modifier on macOS is pressed.
--- @param caps_lock Whether or not Caps Lock is enabled.
--- @return `true` to stop handling the key; `nil` otherwise.
-local function keypress(code, shift, control, alt, cmd, caps_lock)
-  --print(code, M.KEYSYMS[code], shift, control, alt, cmd, caps_lock)
-  if caps_lock and (shift or control or alt or cmd) and code < 256 then
+-- Handles Textadept keypresses, executing commands based on a mode or lexer as
+-- necessary.
+events.connect(events.KEYPRESS, function(code, shift, control, alt, cmd, caps)
+  --print(code, M.KEYSYMS[code], shift, control, alt, cmd, caps)
+  if caps and (shift or control or alt or cmd) and code < 256 then
     code = string[shift and 'upper' or 'lower'](string.char(code)):byte()
   end
   local key = code >= 32 and code < 256 and string.char(code) or M.KEYSYMS[code]
@@ -216,8 +208,7 @@ local function keypress(code, shift, control, alt, cmd, caps_lock)
     return true
   end
   -- PROPAGATE otherwise.
-end
-events.connect(events.KEYPRESS, keypress)
+end)
 
 --[[ This comment is for LuaDoc.
 ---
diff --git a/core/lfs_ext.lua b/core/lfs_ext.lua
index 86a0cada..c24ee2e9 100644
--- a/core/lfs_ext.lua
+++ b/core/lfs_ext.lua
@@ -22,33 +22,6 @@ lfs.default_filter = {--[[Extensions]]'!.a','!.bmp','!.bz2','!.class','!.dll','!
 -- @param level Utility value indicating the directory level this function is
 --   at.
 local function walk(dir, filter, n, include_dirs, level)
-  if not level then
-    -- Convert filter to a table from nil or string arguments.
-    if not filter then filter = lfs.default_filter end
-    if type(filter) == 'string' then filter = {filter} end
-    -- Process the given filter into something that can match files more easily
-    -- and/or quickly. For example, convert '.ext' shorthand to '%.ext$',
-    -- substitute '/' with '[/\\]', and enable hash lookup for file extensions
-    -- to include or exclude.
-    local processed_filter = {
-      consider_any = true,
-      exts = setmetatable({}, {__index = function() return true end})
-    }
-    for _, patt in ipairs(filter) do
-      patt = patt:gsub('^(!?)%%?%.([^.]+)$', '%1%%.%2$') -- '.lua' to '%.lua$'
-      patt = patt:gsub('/([^\\])', '[/\\]%1') -- '/' to '[/\\]'
-      local include = not patt:find('^!')
-      local ext = patt:match('^!?%%.([^.]+)%$$')
-      if ext then
-        processed_filter.exts[ext] = include
-        if include then setmetatable(processed_filter.exts, nil) end
-      else
-        if include then processed_filter.consider_any = false end
-        processed_filter[#processed_filter + 1] = patt
-      end
-    end
-    filter = processed_filter
-  end
   for basename in lfs.dir(dir) do
     if basename:find('^%.%.?$') then goto continue end -- ignore . and ..
     local filename = dir .. (dir ~= '/' and '/' or '') .. basename
@@ -68,14 +41,15 @@ local function walk(dir, filter, n, include_dirs, level)
       -- Treat inclusive patterns as logical OR.
       include = include or (not patt:find('^!') and filename:find(patt))
     end
+    if not include then goto continue end
     local sep = not WIN32 and '/' or '\\'
     local os_filename = not WIN32 and filename or filename:gsub('/', sep)
-    if include and mode == 'directory' then
+    if mode == 'file' then
+      coroutine.yield(os_filename)
+    elseif mode == 'directory' then
       if include_dirs then coroutine.yield(os_filename .. sep) end
       if n and (level or 0) >= n then goto continue end
       walk(filename, filter, n, include_dirs, (level or 0) + 1)
-    elseif include and mode == 'file' then
-      coroutine.yield(os_filename)
     end
     ::continue::
   end
@@ -104,9 +78,33 @@ end
 -- @name walk
 function lfs.walk(dir, filter, n, include_dirs)
   assert_type(dir, 'string', 1)
-  assert_type(filter, 'string/table/nil', 2)
+  if not assert_type(filter, 'string/table/nil', 2) then
+    filter = lfs.default_filter
+  end
   assert_type(n, 'number/nil', 3)
-  local co = coroutine.create(function() walk(dir, filter, n, include_dirs) end)
+  -- Process the given filter into something that can match files more easily
+  -- and/or quickly. For example, convert '.ext' shorthand to '%.ext$',
+  -- substitute '/' with '[/\\]', and enable hash lookup for file extensions
+  -- to include or exclude.
+  local processed_filter = {
+    consider_any = true,
+    exts = setmetatable({}, {__index = function() return true end})
+  }
+  for _, patt in ipairs(type(filter) == 'table' and filter or {filter}) do
+    patt = patt:gsub('^(!?)%%?%.([^.]+)$', '%1%%.%2$') -- '.lua' to '%.lua$'
+    patt = patt:gsub('/([^\\])', '[/\\]%1') -- '/' to '[/\\]'
+    local include = not patt:find('^!')
+    local ext = patt:match('^!?%%.([^.]+)%$$')
+    if ext then
+      processed_filter.exts[ext] = include
+      if include then setmetatable(processed_filter.exts, nil) end
+    else
+      if include then processed_filter.consider_any = false end
+      processed_filter[#processed_filter + 1] = patt
+    end
+  end
+  local co = coroutine.create(
+    function() walk(dir, processed_filter, n, include_dirs) end)
   return function() return select(2, coroutine.resume(co)) end
 end
 
diff --git a/core/locale.conf b/core/locale.conf
index d5f60436..18a62e2b 100644
--- a/core/locale.conf
+++ b/core/locale.conf
@@ -336,9 +336,6 @@ Help = _Help
 Show Manual = Show _Manual
 Show LuaDoc = Show _LuaDoc
 About = _About
-# The error message displayed when activating a menu item associated with an
-# unknown command.
-Unknown command: = Unknown command:
 # The text displayed in the dialog for running an arbitrary menu command. Any
 # key binding associated with commands are also shown.
 Run Command = Run Command
diff --git a/core/locale.lua b/core/locale.lua
index 48701116..3a661fae 100644
--- a/core/locale.lua
+++ b/core/locale.lua
@@ -23,14 +23,14 @@ assert(f, '"core/locale.conf" not found')
 for line in f:lines() do
   -- Any line that starts with a non-word character except '[' is considered a
   -- comment.
-  if not line:find('^%s*[^%w_%[]') then
-    local id, str = line:match('^(.-)%s*=%s*(.-)\r?$')
-    if id and str and assert(not M[id], 'duplicate locale key "%s"', id) then
-      M[id] = not CURSES and str or str:gsub('_', '')
-    end
+  if not line:find('^%s*[%w_%[]') then goto continue end
+  local id, str = line:match('^(.-)%s*=%s*(.-)\r?$')
+  if id and str and assert(not M[id], 'duplicate locale key "%s"', id) then
+    M[id] = not CURSES and str or str:gsub('_', '')
   end
+  ::continue::
 end
 f:close()
 
-setmetatable(M, {__index = function(_, k) return 'No Localization:' .. k end})
-return M
+return setmetatable(
+  M, {__index = function(_, k) return 'No Localization:' .. k end})
diff --git a/core/locales/locale.ar.conf b/core/locales/locale.ar.conf
index 953d3d38..e894445e 100644
--- a/core/locales/locale.ar.conf
+++ b/core/locales/locale.ar.conf
@@ -336,9 +336,6 @@ Help = م_ساعدة
 Show Manual = عرض الد_ليل
 Show LuaDoc = عرض و_ثائق لُوَ
 About = ع_ن
-# The error message displayed when activating a menu item associated with an
-# unknown command.
-Unknown command: = أمر مجهول:
 # The text displayed in the dialog for running an arbitrary menu command. Any
 # key binding associated with commands are also shown.
 Run Command = شغِّل الأمر
diff --git a/core/locales/locale.de.conf b/core/locales/locale.de.conf
index 22d46b5c..d73ca229 100644
--- a/core/locales/locale.de.conf
+++ b/core/locales/locale.de.conf
@@ -336,9 +336,6 @@ Help = _Hilfe
 Show Manual = Handbuch anzeigen
 Show LuaDoc = LuaDoc anzeigen
 About = _Über Textadept
-# The error message displayed when activating a menu item associated with an
-# unknown command.
-Unknown command: = Unbekannter Befehl:
 # The text displayed in the dialog for running an arbitrary menu command. Any
 # key binding associated with commands are also shown.
 Run Command = Befehl ausführen
diff --git a/core/locales/locale.es.conf b/core/locales/locale.es.conf
index 354a33fc..273b90ca 100644
--- a/core/locales/locale.es.conf
+++ b/core/locales/locale.es.conf
@@ -336,9 +336,6 @@ Help = A_yuda
 Show Manual = Mostrar _manual
 Show LuaDoc = Mostrar _LuaDoc
 About = Acerca _de
-# The error message displayed when activating a menu item associated with an
-# unknown command.
-Unknown command: = Comando desconocido:
 # The text displayed in the dialog for running an arbitrary menu command. Any
 # key binding associated with commands are also shown.
 Run Command = Ejecutar comando
diff --git a/core/locales/locale.fr.conf b/core/locales/locale.fr.conf
index b2fff92d..f3afccfa 100644
--- a/core/locales/locale.fr.conf
+++ b/core/locales/locale.fr.conf
@@ -337,9 +337,6 @@ Help = Aid_e
 Show Manual = Voir _manuel
 Show LuaDoc = Voir la documentation sur l’_API
 About = À _propos
-# The error message displayed when activating a menu item associated with an
-# unknown command.
-Unknown command: = Commande inconnue:
 # The text displayed in the dialog for running an arbitrary menu command. Any
 # key binding associated with commands are also shown.
 Run Command = Lancer une commande
diff --git a/core/locales/locale.it.conf b/core/locales/locale.it.conf
index 91d4958a..d9c508a1 100644
--- a/core/locales/locale.it.conf
+++ b/core/locales/locale.it.conf
@@ -336,9 +336,6 @@ Help = _Aiuto
 Show Manual = _Manuale
 Show LuaDoc = _Documentazione sull’API
 About = _Informazioni
-# The error message displayed when activating a menu item associated with an
-# unknown command.
-Unknown command: = Comando sconosciuto:
 # The text displayed in the dialog for running an arbitrary menu command. Any
 # key binding associated with commands are also shown.
 Run Command = Scegli un comando
diff --git a/core/locales/locale.pl.conf b/core/locales/locale.pl.conf
index bbe34282..a33b1d69 100644
--- a/core/locales/locale.pl.conf
+++ b/core/locales/locale.pl.conf
@@ -337,9 +337,6 @@ Help = P_omoc
 Show Manual = Po_dręcznik użytkownika...
 Show LuaDoc = _LuaDoc...
 About = _O programie...
-# The error message displayed when activating a menu item associated with an
-# unknown command.
-Unknown command: = Nieznane polecenie:
 # The text displayed in the dialog for running an arbitrary menu command. Any
 # key binding associated with commands are also shown.
 Run Command = Wykonaj polecenie
diff --git a/core/locales/locale.ru.conf b/core/locales/locale.ru.conf
index 3bfb7198..476d0f63 100644
--- a/core/locales/locale.ru.conf
+++ b/core/locales/locale.ru.conf
@@ -336,9 +336,6 @@ Help = _Справка
 Show Manual = Показать _руководство
 Show LuaDoc = Показать документацию по _lua
 About = _О программе
-# The error message displayed when activating a menu item associated with an
-# unknown command.
-Unknown command: = Неизвестная команда:
 # The text displayed in the dialog for running an arbitrary menu command. Any
 # key binding associated with commands are also shown.
 Run Command = Выполнить команду
diff --git a/core/locales/locale.sv.conf b/core/locales/locale.sv.conf
index d56d2456..f6f01d17 100644
--- a/core/locales/locale.sv.conf
+++ b/core/locales/locale.sv.conf
@@ -336,9 +336,6 @@ Help = _Hjälp
 Show Manual = _Manual
 Show LuaDoc = _LuaDoc
 About = _Om
-# The error message displayed when activating a menu item associated with an
-# unknown command.
-Unknown command: = Okänt kommando:
 # The text displayed in the dialog for running an arbitrary menu command. Any
 # key binding associated with commands are also shown.
 Run Command = Kör kommando
diff --git a/core/locales/locale.zh.conf b/core/locales/locale.zh.conf
index dbce6e55..54476596 100644
--- a/core/locales/locale.zh.conf
+++ b/core/locales/locale.zh.conf
@@ -336,9 +336,6 @@ Help = 帮助(_H)
 Show Manual = 打开手册(_M)
 Show LuaDoc = 打开_LuaDoc
 About = 关于(_A)
-# The error message displayed when activating a menu item associated with an
-# unknown command.
-Unknown command: = 未知命令:
 # The text displayed in the dialog for running an arbitrary menu command. Any
 # key binding associated with commands are also shown.
 Run Command = 运行命令
diff --git a/core/ui.lua b/core/ui.lua
index 343b4510..73616719 100644
--- a/core/ui.lua
+++ b/core/ui.lua
@@ -37,6 +37,12 @@ module('ui')]]
 
 ui.silent_print = false
 
+-- Helper function for jumping to another view to print to, or creating a new
+-- view to print to (the latter depending on settings).
+local function prepare_view()
+  if #_VIEWS > 1 then ui.goto_view(1) elseif not ui.tabs then view:split() end
+end
+
 -- Helper function for printing messages to buffers.
 -- @see ui._print
 local function _print(buffer_type, ...)
@@ -45,21 +51,19 @@ local function _print(buffer_type, ...)
     if buf._type == buffer_type then buffer = buf break end
   end
   if not buffer then
-    if not ui.tabs then view:split() end
+    prepare_view()
     buffer = _G.buffer.new()
     buffer._type = buffer_type
   elseif not ui.silent_print then
     for _, view in ipairs(_VIEWS) do
-      if view.buffer._type == buffer_type then ui.goto_view(view) break end
-    end
-    if view.buffer._type ~= buffer_type then
-      if #_VIEWS > 1 then
-        ui.goto_view(1)
-      elseif not ui.tabs then
-        view:split()
+      if view.buffer._type == buffer_type then
+        ui.goto_view(view)
+        goto view_found
       end
-      view:goto_buffer(buffer)
     end
+    prepare_view()
+    view:goto_buffer(buffer)
+    ::view_found::
   end
   local args, n = {...}, select('#', ...)
   for i = 1, n do args[i] = tostring(args[i]) end
@@ -115,8 +119,7 @@ ui.dialogs = setmetatable({}, {__index = function(_, k)
     -- Transform key-value pairs into command line arguments.
     local args = {}
     for option, value in pairs(options) do
-      assert_type(value, 'string/number/table/boolean', option)
-      if value then
+      if assert_type(value, 'string/number/table/boolean', option) then
         args[#args + 1] = '--' .. option:gsub('_', '-')
         if type(value) == 'table' then
           for i, val in ipairs(value) do
@@ -139,7 +142,7 @@ ui.dialogs = setmetatable({}, {__index = function(_, k)
     if k == 'progressbar' then
       args[#args + 1] = assert_type(f, 'function', 2)
     end
-    -- Call gtdialog, stripping any trailing newline in the standard output.
+    -- Call gtdialog, stripping any trailing newline in the output.
     local result = ui.dialog(
       k:gsub('_', '-'), table.unpack(args)):match('^(.-)\n?$')
     -- Depending on the dialog type, transform the result into Lua objects.
@@ -185,12 +188,10 @@ ui.dialogs = setmetatable({}, {__index = function(_, k)
   end
 end})
 
-local events, events_connect = events, events.connect
-
 local buffers_zorder = {}
 
 -- Adds new buffers to the z-order list.
-events_connect(events.BUFFER_NEW, function()
+events.connect(events.BUFFER_NEW, function()
   if buffer ~= ui.command_entry then table.insert(buffers_zorder, 1, buffer) end
 end)
 
@@ -206,13 +207,14 @@ local function update_zorder()
   end
   table.insert(buffers_zorder, 1, buffer)
 end
-events_connect(events.BUFFER_AFTER_SWITCH, update_zorder)
-events_connect(events.VIEW_AFTER_SWITCH, update_zorder)
+events.connect(events.BUFFER_AFTER_SWITCH, update_zorder)
+events.connect(events.VIEW_AFTER_SWITCH, update_zorder)
+events.connect(events.BUFFER_DELETED, update_zorder)
 
 -- Saves and restores buffer zorder data during a reset.
-events_connect(
+events.connect(
   events.RESET_BEFORE, function(persist) persist.ui_zorder = buffers_zorder end)
-events_connect(
+events.connect(
   events.RESET_AFTER, function(persist) buffers_zorder = persist.ui_zorder end)
 
 ---
@@ -237,9 +239,8 @@ function ui.switch_buffer(zorder)
   local button, i = ui.dialogs.filteredlist{
     title = _L['Switch Buffers'], columns = columns, items = utf8_list
   }
-  if button == 1 and i then
-    view:goto_buffer(buffers[not zorder and i or i + 1])
-  end
+  if button ~= 1 or not i then return end
+  view:goto_buffer(buffers[not zorder and i or i + 1])
 end
 
 ---
@@ -290,10 +291,10 @@ function ui.goto_file(filename, split, preferred_view, sloppy)
 end
 
 -- Ensure title, statusbar, etc. are updated for new views.
-events_connect(events.VIEW_NEW, function() events.emit(events.UPDATE_UI, 3) end)
+events.connect(events.VIEW_NEW, function() events.emit(events.UPDATE_UI, 3) end)
 
 -- Switches between buffers when a tab is clicked.
-events_connect(
+events.connect(
   events.TAB_CLICKED, function(index) view:goto_buffer(_BUFFERS[index]) end)
 
 -- Sets the title of the Textadept window to the buffer's filename.
@@ -309,11 +310,11 @@ local function set_title()
 end
 
 -- Changes Textadept title to show the buffer as being "clean" or "dirty".
-events_connect(events.SAVE_POINT_REACHED, set_title)
-events_connect(events.SAVE_POINT_LEFT, set_title)
+events.connect(events.SAVE_POINT_REACHED, set_title)
+events.connect(events.SAVE_POINT_LEFT, set_title)
 
 -- Open uri(s).
-events_connect(events.URI_DROPPED, function(utf8_uris)
+events.connect(events.URI_DROPPED, function(utf8_uris)
   for utf8_path in utf8_uris:gmatch('file://([^\r\n]+)') do
     local path = utf8_path:gsub('%%(%x%x)', function(hex)
       return string.char(tonumber(hex, 16))
@@ -325,25 +326,25 @@ events_connect(events.URI_DROPPED, function(utf8_uris)
   end
   ui.goto_view(view) -- work around any view focus synchronization issues
 end)
-events_connect(events.APPLEEVENT_ODOC, function(uri)
+events.connect(events.APPLEEVENT_ODOC, function(uri)
   return events.emit(events.URI_DROPPED, 'file://' .. uri)
 end)
 
 -- Sets buffer statusbar text.
-events_connect(events.UPDATE_UI, function(updated)
+events.connect(events.UPDATE_UI, function(updated)
   if updated & 3 == 0 then return end -- ignore scrolling
   local text = not CURSES and '%s %d/%d    %s %d    %s    %s    %s    %s' or
     '%s %d/%d  %s %d  %s  %s  %s  %s'
-  local pos = buffer.selection_n_caret[buffer.main_selection]
+  local pos = buffer.current_pos
   local line, max = buffer:line_from_position(pos), buffer.line_count
   local col = buffer.column[pos]
   local lang = buffer:get_lexer()
   local eol = buffer.eol_mode == buffer.EOL_CRLF and _L['CRLF'] or _L['LF']
   local tabs = string.format(
     '%s %d', buffer.use_tabs and _L['Tabs:'] or _L['Spaces:'], buffer.tab_width)
-  local enc = buffer.encoding or ''
+  local encoding = buffer.encoding or ''
   ui.buffer_statusbar_text = string.format(
-    text, _L['Line:'], line, max, _L['Col:'], col, lang, eol, tabs, enc)
+    text, _L['Line:'], line, max, _L['Col:'], col, lang, eol, tabs, encoding)
 end)
 
 -- Save buffer properties.
@@ -357,19 +358,17 @@ local function save_buffer_state()
   buffer._x_offset = view.x_offset
   -- Save fold state.
   local folds, i = {}, view:contracted_fold_next(1)
-  while i >= 1 do
-    folds[#folds + 1], i = i, view:contracted_fold_next(i + 1)
-  end
+  while i >= 1 do folds[#folds + 1], i = i, view:contracted_fold_next(i + 1) end
   buffer._folds = folds
 end
-events_connect(events.BUFFER_BEFORE_SWITCH, save_buffer_state)
-events_connect(events.FILE_BEFORE_RELOAD, save_buffer_state)
+events.connect(events.BUFFER_BEFORE_SWITCH, save_buffer_state)
+events.connect(events.FILE_BEFORE_RELOAD, save_buffer_state)
 
 -- Restore buffer properties.
 local function restore_buffer_state()
   if not buffer._folds then return end
   -- Restore fold state.
-  for i = 1, #buffer._folds do view:toggle_fold(buffer._folds[i]) end
+  for _, line in ipairs(buffer._folds) do view:toggle_fold(line) end
   -- Restore view state.
   buffer:set_sel(buffer._anchor, buffer._current_pos)
   buffer.selection_n_anchor_virtual_space[1] = buffer._anchor_virtual_space
@@ -379,17 +378,17 @@ local function restore_buffer_state()
   view:line_scroll(0, view:visible_from_doc_line(_top_line) - top_line)
   view.x_offset = buffer._x_offset or 0
 end
-events_connect(events.BUFFER_AFTER_SWITCH, restore_buffer_state)
-events_connect(events.FILE_AFTER_RELOAD, restore_buffer_state)
+events.connect(events.BUFFER_AFTER_SWITCH, restore_buffer_state)
+events.connect(events.FILE_AFTER_RELOAD, restore_buffer_state)
 
 -- Updates titlebar and statusbar.
 local function update_bars()
   set_title()
   events.emit(events.UPDATE_UI, 3)
 end
-events_connect(events.BUFFER_NEW, update_bars)
-events_connect(events.BUFFER_AFTER_SWITCH, update_bars)
-events_connect(events.VIEW_AFTER_SWITCH, update_bars)
+events.connect(events.BUFFER_NEW, update_bars)
+events.connect(events.BUFFER_AFTER_SWITCH, update_bars)
+events.connect(events.VIEW_AFTER_SWITCH, update_bars)
 
 -- Save view state.
 local function save_view_state()
@@ -400,8 +399,8 @@ local function save_view_state()
     buffer._margin_width_n[i] = view.margin_width_n[i]
   end
 end
-events_connect(events.BUFFER_BEFORE_SWITCH, save_view_state)
-events_connect(events.VIEW_BEFORE_SWITCH, save_view_state)
+events.connect(events.BUFFER_BEFORE_SWITCH, save_view_state)
+events.connect(events.VIEW_BEFORE_SWITCH, save_view_state)
 
 -- Restore view state.
 local function restore_view_state()
@@ -412,21 +411,21 @@ local function restore_view_state()
     view.margin_width_n[i] = buffer._margin_width_n[i]
   end
 end
-events_connect(events.BUFFER_AFTER_SWITCH, restore_view_state)
-events_connect(events.VIEW_AFTER_SWITCH, restore_view_state)
+events.connect(events.BUFFER_AFTER_SWITCH, restore_view_state)
+events.connect(events.VIEW_AFTER_SWITCH, restore_view_state)
 
-events_connect(
+events.connect(
   events.RESET_AFTER, function() ui.statusbar_text = _L['Lua reset'] end)
 
 -- Prompts for confirmation if any buffers are modified.
-events_connect(events.QUIT, function()
+events.connect(events.QUIT, function()
   local utf8_list = {}
   for _, buffer in ipairs(_BUFFERS) do
-    if buffer.modify then
-      local filename = buffer.filename or buffer._type or _L['Untitled']
-      if buffer.filename then filename = filename:iconv('UTF-8', _CHARSET) end
-      utf8_list[#utf8_list + 1] = filename
-    end
+    if not buffer.modify then goto continue end
+    local filename = buffer.filename or buffer._type or _L['Untitled']
+    if buffer.filename then filename = filename:iconv('UTF-8', _CHARSET) end
+    utf8_list[#utf8_list + 1] = filename
+    ::continue::
   end
   if #utf8_list == 0 then return end
   local button = ui.dialogs.msgbox{
@@ -440,10 +439,10 @@ events_connect(events.QUIT, function()
   if button ~= 2 then return true end -- prevent quit
 end)
 
--- Keeps track of and switches back to the previous buffer after buffer close.
-events_connect(
+-- Keeps track of, and switches back to the previous buffer after buffer close.
+events.connect(
   events.BUFFER_BEFORE_SWITCH, function() view._prev_buffer = buffer end)
-events_connect(events.BUFFER_DELETED, function()
+events.connect(events.BUFFER_DELETED, function()
   if _BUFFERS[view._prev_buffer] and buffer ~= view._prev_buffer then
     view:goto_buffer(view._prev_buffer)
   end
@@ -452,19 +451,20 @@ end)
 -- Properly handle clipboard text between views in curses, enables and disables
 -- mouse mode, and focuses and resizes views based on mouse events.
 if CURSES then
-  local clip_text
-  events.connect(
-    events.VIEW_BEFORE_SWITCH, function() clip_text = ui.clipboard_text end)
-  events.connect(
-    events.VIEW_AFTER_SWITCH, function() ui.clipboard_text = clip_text end)
+  events.connect(events.VIEW_BEFORE_SWITCH, function()
+    ui._clipboard_text = ui.clipboard_text
+  end)
+  events.connect(events.VIEW_AFTER_SWITCH, function()
+    ui.clipboard_text = ui._clipboard_text
+  end)
 
   if not WIN32 then
     local function enable_mouse() io.stdout:write("\x1b[?1002h"):flush() end
     local function disable_mouse() io.stdout:write("\x1b[?1002l"):flush() end
     enable_mouse()
-    events_connect(events.SUSPEND, disable_mouse)
-    events_connect(events.RESUME, enable_mouse)
-    events_connect(events.QUIT, disable_mouse)
+    events.connect(events.SUSPEND, disable_mouse)
+    events.connect(events.RESUME, enable_mouse)
+    events.connect(events.QUIT, disable_mouse)
   end
 
   -- Retrieves the view or split at the given terminal coordinates.
@@ -486,7 +486,7 @@ if CURSES then
   end
 
   local resize
-  events_connect(events.MOUSE, function(event, button, y, x)
+  events.connect(events.MOUSE, function(event, button, y, x)
     if event == view.MOUSE_RELEASE or button ~= 1 then return end
     if event == view.MOUSE_PRESS then
       local view = get_view(ui.get_split_table(), y - 1, x) -- title is at y = 1
@@ -511,7 +511,7 @@ events.connect(events.INITIALIZED, function()
   -- Print internal Lua error messages as they are reported.
   -- Attempt to mimic the Lua interpreter's error message format so tools that
   -- look for it can recognize these errors too.
-  events_connect(events.ERROR, function(text)
+  events.connect(events.ERROR, function(text)
     if text and text:find(lua_error) then text = 'lua: ' .. text end
     ui.print(text)
   end)