doc/startup: cleanup; assign ENN to "conflicing configs" msg (#14971)

runtime/doc/repeat.txt

@@ -172,42 +172,34 @@ Using Vim scripts					*using-scripts*
 For writing a Vim script, see chapter 41 of the user manual |usr_41.txt|.
 
 					*:so* *:source* *load-vim-script*
-:so[urce] {file}	Runs vim or lua {file}
+:so[urce] {file}	Runs |Ex| commands or Lua code (".lua" files) read
+			from {file}.
 			Triggers the |SourcePre| autocommand.
-
-			Note: Only files ending with `.lua` is sourced as
-			lua file. Anything else is assumed to be vimscript.
 							*:source!*
-:so[urce]! {file}	Read Vim commands from {file}.  These are commands
-			that are executed from Normal mode, like you type
-			them.
-			When used after |:global|, |:argdo|, |:windo|,
-			|:bufdo|, in a loop or when another command follows
-			the display won't be updated while executing the
-			commands.
+:so[urce]! {file}	Runs |Normal-mode| commands read from {file}. When
+			used after |:global|, |:argdo|, |:windo|, |:bufdo|, in
+			a loop or when another command follows the display
+			won't be updated while executing the commands.
 			Cannot be used in the |sandbox|.
 
 							*:ru* *:runtime*
 :ru[ntime][!] [where] {file} ..
-			Source vim/lua {file} in each directory given by
-			'runtimepath' and/or 'packpath'. The vim files are
-			executed in same mannar as |:source| and lua files
-			similarly as |:luafile|. There is no error
-			for non-existing files.
+			Sources |Ex| commands or Lua code (".lua" files) read
+			from {file} (a relative path) in each directory given
+			by 'runtimepath' and/or 'packpath'.
+			Ignores non-existing files.
 
 			Example: >
 				:runtime syntax/c.vim
+				:runtime syntax/c.lua
 
-<			There can be multiple {file} arguments, separated by
-			spaces.  Each {file} is searched for in the first
+<			There can be multiple space-separated {file}
+			arguments. Each {file} is searched for in the first
 			directory from 'runtimepath', then in the second
-			directory, etc.  Use a backslash to include a space
-			inside {file} (although it's better not to use spaces
-			in file names, it causes trouble).
+			directory, etc.
 
 			When [!] is included, all found files are sourced.
-			When it is not included only the first found file is
-			sourced.
+			Else only the first found file is sourced.
 
 			When [where] is omitted only 'runtimepath' is used.
 			Other values:

runtime/doc/starting.txt

@@ -407,20 +407,18 @@ accordingly.  Vim proceeds in this order:
 	proceeding to load user configuration.
 
 4. Load user config (execute Ex commands from files, environment, …).
-	An environment variable (e.g. $VIMINIT) is read as one Ex command
-	line, where multiple commands must be separated with '|' or <NL>.
+	$VIMINIT environment variable is read as one Ex command line (separate
+	multiple commands with '|' or <NL>).
 					*config* *init.vim* *init.lua* *vimrc* *exrc*
-	A file that contains initialization commands is generically called
-	a "vimrc" or config file.  It can be a Vimscript or Lua file named
-	"init.vim" or "init.lua" respectively.  It is an error to use both at
-	the same time.  Each line in a "init.vim" is executed as an Ex command
-	line.  See also |vimrc-intro| and |base-directories|.
+	A file containing initialization commands is generically called
+	a "vimrc" or config file.  It can be either Vimscript ("init.vim") or
+	Lua ("init.lua"), but not both. *E5422*
+	See also |vimrc-intro| and |base-directories|.
 
 	The config file is located at:
 	Unix			~/.config/nvim/init.vim		(or init.lua)
 	Windows			~/AppData/Local/nvim/init.vim	(or init.lua)
-	or if |$XDG_CONFIG_HOME| is defined:
-				$XDG_CONFIG_HOME/nvim/init.vim (or init.lua)
+	|$XDG_CONFIG_HOME|	$XDG_CONFIG_HOME/nvim/init.vim	(or init.lua)
 
 	If Nvim was started with "-u {file}" then {file} is used as the config
 	and all initializations until 5. are skipped. $MYVIMRC is not set.
@@ -470,14 +468,11 @@ accordingly.  Vim proceeds in this order:
 	This does the same as the command: >
 		:runtime! plugin/**/*.vim
 		:runtime! plugin/**/*.lua
-<	The result is that all directories in the 'runtimepath' option will be
-	searched for the "plugin" sub-directory and all files ending in ".vim"
-	and ".lua" will be sourced (in alphabetical order per directory),
-	also in subdirectories. First all the "*.vim" files will be sourced and
-	then all the "*.lua" files will be sourced. If two files with same
-	name but different extensions exists they will be treated in same
-	manner. For example when both "foo.vim" and "foo.lua" exists then
-	first "foo.vim" will be sourced then "foo.lua" will be sourced.
+<	The result is that all directories in 'runtimepath' will be searched
+	for the "plugin" sub-directory and all files ending in ".vim" or
+	".lua" will be sourced (in alphabetical order per directory),
+	also in subdirectories. First "*.vim" are sourced, then "*.lua" files.
+
 	However, directories in 'runtimepath' ending in "after" are skipped
 	here and only loaded after packages, see below.
 	Loading plugins won't be done when:

src/nvim/main.c

@@ -1816,7 +1816,8 @@ static bool do_user_initialization(void)
     char_u *vimrc_path = (char_u *)stdpaths_user_conf_subpath("init.vim");
 
     if (os_path_exists(vimrc_path)) {
-      EMSG3(_("Conflicting configs: \"%s\" \"%s\""), init_lua_path, vimrc_path);
+      EMSG3(_("E5422: Conflicting configs: \"%s\" \"%s\""), init_lua_path,
+            vimrc_path);
     }
 
     xfree(vimrc_path);

test/functional/core/startup_spec.lua

@@ -487,7 +487,7 @@ describe('user config init', function()
       clear{ args_rm={'-u'}, env={ XDG_CONFIG_HOME=xconfig }}
       feed('<cr>') -- TODO check this, test execution is blocked without it
       eq(1, eval('g:lua_rc'))
-      matches('Conflicting configs', meths.exec('messages', true))
+      matches('^E5422: Conflicting configs', meths.exec('messages', true))
     end)
   end)
 end)