patch 9.1.0327: No support for using $XDG_CONFIG_HOME

Problem:  No support for using $XDG_CONFIG_HOME
Solution: optionally source $XDG_CONFIG_HOME/vim/vimrc
          (Luca Saccarola)

fixes: #2034
closes: #14182

Signed-off-by: Luca Saccarola <github.e41mv@aleeas.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>

runtime/doc/starting.txt

@@ -1,4 +1,4 @@
-*starting.txt*  For Vim version 9.1.  Last change: 2024 Mar 13
+*starting.txt*  For Vim version 9.1.  Last change: 2024 Apr 14
 
 
 		  VIM REFERENCE MANUAL    by Bram Moolenaar
@@ -811,7 +811,8 @@ accordingly.  Vim proceeds in this order:
 	name.  Also see |vimrc-intro|.
 
 	Places for your personal initializations:
-		Unix		$HOME/.vimrc or $HOME/.vim/vimrc
+		Unix		$HOME/.vimrc, $HOME/.vim/vimrc
+                                or $XDG_CONFIG_HOME/vim/vimrc
 		MS-Windows	$HOME/_vimrc, $HOME/vimfiles/vimrc
 				or $VIM/_vimrc
 		Amiga		s:.vimrc, home:.vimrc, home:vimfiles:vimrc
@@ -853,15 +854,16 @@ accordingly.  Vim proceeds in this order:
 	I   The environment variable VIMINIT (see also |compatible-default|) (*)
 	    The value of $VIMINIT is used as an Ex command line.
 	II  The user vimrc file(s):
-		    "$HOME/.vimrc"	   (for Unix) (*)
-		    "$HOME/.vim/vimrc"	   (for Unix) (*)
-		    "s:.vimrc"		   (for Amiga) (*)
-		    "home:.vimrc"	   (for Amiga) (*)
-		    "home:vimfiles:vimrc"  (for Amiga) (*)
-		    "$VIM/.vimrc"	   (for Amiga) (*)
-		    "$HOME/_vimrc"	   (for Win32) (*)
-		    "$HOME/vimfiles/vimrc" (for Win32) (*)
-		    "$VIM/_vimrc"	   (for Win32) (*)
+		    "$HOME/.vimrc"		(for Unix) (*)
+		    "$HOME/.vim/vimrc"		(for Unix) (*)
+		    "$HOME/.config/vim/vimrc"	(for Unix) (*)
+		    "s:.vimrc"			(for Amiga) (*)
+		    "home:.vimrc"		(for Amiga) (*)
+		    "home:vimfiles:vimrc"	(for Amiga) (*)
+		    "$VIM/.vimrc"		(for Amiga) (*)
+		    "$HOME/_vimrc"		(for Win32) (*)
+		    "$HOME/vimfiles/vimrc"	(for Win32) (*)
+		    "$VIM/_vimrc"		(for Win32) (*)
 		    "$HOME/config/settings/vim/vimrc"	(for Haiku) (*)
 
 		Note: For Unix and Amiga, when ".vimrc" does not exist,
@@ -1085,6 +1087,44 @@ defaults.vim from your .vimrc, first unlet skip_defaults_vim, as in the
 example above.
 
 
+					*xdg-base-dir* *$XDG_CONFIG_HOME*
+XDG Base Directory Specification ~
+
+The XDG Base Directory Specification aims to define a standard location for
+configuration files used by applications.  This is mainly done to prevent
+the legacy behavior of dumping everything into the users home directory.
+The specification can be found online at
+https://specifications.freedesktop.org/basedir-spec/latest/
+
+The location of this standard configuration directory is configurable by the
+user, using environment variable but should also give fallback in case those
+variables weren't set.
+
+This is a not an exhaustive list of those directories:
+   Environment var	default location	Description ~
+  `$XDG_CACHE_HOME`	$HOME/.cache		Ephemiral data files
+  `$XDG_CONFIG_HOME`	$HOME/.config		Configuration files
+  `$XDG_DATA_HOME`	$HOME/.local/share	Persistent data files
+  `$XDG_STATE_HOME`	$HOME/.local/state	State data files
+
+Vim will only care of the `$XDG_CONFIG_HOME` directory, the others are not
+(yet) used for its various configuration and state files.
+
+							*xdg-vimrc*
+Vim, on Unix systems, will look at `$XDG_CONFIG_HOME/vim/vimrc` for its
+configuration (see |vimrc|) but it will source it only if no other
+initialization file is found in `$HOME` or `$HOME/.vim` (thus making this
+feature backward compatible). However, if you want to migrate to use
+`$XDG_CONFIG_HOME/vim/` directory, you will have to move away your `~/.vimrc`
+and `~/.vim/vimrc` file.
+
+							*xdg-runtime*
+When the |xdg-vimrc| is used the |'runtimepath'| will be modified accordingly
+to respect the |xdg-base-dir|: >
+
+    "$XDG_CONFIG_HOME/vim,$VIMRUNTIME,/after,$XDG_CONFIG_HOME/vim/after"
+<
+
 Avoiding trojan horses ~
 							*trojan-horse*
 While reading the "vimrc" or the "exrc" file in the current directory, some

runtime/doc/tags

@@ -12,6 +12,7 @@ $VIM	starting.txt	/*$VIM*
 $VIM-use	version5.txt	/*$VIM-use*
 $VIMRUNTIME	starting.txt	/*$VIMRUNTIME*
 $VIM_POSIX	vi_diff.txt	/*$VIM_POSIX*
+$XDG_CONFIG_HOME	starting.txt	/*$XDG_CONFIG_HOME*
 $quote	eval.txt	/*$quote*
 %	motion.txt	/*%*
 %:.	cmdline.txt	/*%:.*
@@ -11371,6 +11372,9 @@ x11-clientserver	remote.txt	/*x11-clientserver*
 x11-cut-buffer	gui_x11.txt	/*x11-cut-buffer*
 x11-selection	gui_x11.txt	/*x11-selection*
 xattr	editing.txt	/*xattr*
+xdg-base-dir	starting.txt	/*xdg-base-dir*
+xdg-runtime	starting.txt	/*xdg-runtime*
+xdg-vimrc	starting.txt	/*xdg-vimrc*
 xf86conf.vim	syntax.txt	/*xf86conf.vim*
 xfontset	mbyte.txt	/*xfontset*
 xfree-xterm	syntax.txt	/*xfree-xterm*

runtime/doc/version9.txt

@@ -41543,6 +41543,8 @@ and is a work in progress.
 
 Support for Wayland UI.
 
+Support for the XDG Desktop Specification |xdg-base-dir|
+
 Vim9 script
 -----------
 Add support for internal builtin functions with vim9 objects, see

src/main.c

@@ -3276,6 +3276,10 @@ source_startup_scripts(mparm_T *parmp)
 		&& do_source((char_u *)USR_VIMRC_FILE2, TRUE,
 						      DOSO_VIMRC, NULL) == FAIL
 #endif
+#ifdef XDG_VIMRC_FILE
+		&& do_source((char_u *)XDG_VIMRC_FILE, TRUE,
+						      DOSO_VIMRC, NULL) == FAIL
+#endif
 #ifdef USR_VIMRC_FILE3
 		&& do_source((char_u *)USR_VIMRC_FILE3, TRUE,
 						      DOSO_VIMRC, NULL) == FAIL

src/option.c

@@ -364,6 +364,66 @@ set_init_clean_rtp(void)
 }
 #endif
 
+#ifdef UNIX
+/*
+ * Change 'runtimepath' and 'packdir' to '$XDG_CONFIG_HOME/vim' if the only
+ * vimrc found is located in '$XDG_CONFIG_HOME/vim/vimrc'.
+ * In case the '$XDG_CONFIG_HOME' variable is not set, '$HOME/.config' is used
+ * as a fallback as is defined in the XDG base dir specification:
+ * <https://specifications.freedesktop.org/basedir-spec/basedir-spec-latest.html>
+ */
+    static void
+set_init_xdg_rtp(void)
+{
+    int		opt_idx;
+    int		has_xdg_env = TRUE;
+    int		should_free_xdg_dir = FALSE;
+    char_u	*vimrc1 = NULL;
+    char_u	*vimrc2 = NULL;
+    char_u	*xdg_dir = NULL;
+    char_u	*xdg_rtp = NULL;
+    char_u	*vimrc_xdg = NULL;
+
+    vimrc1 = expand_env_save((char_u *)USR_VIMRC_FILE);
+    vimrc2 = expand_env_save((char_u *)USR_VIMRC_FILE2);
+
+    xdg_dir = mch_getenv("XDG_CONFIG_HOME");
+    if (!xdg_dir)
+    {
+	xdg_dir = expand_env_save((char_u *)"~/.config");
+	should_free_xdg_dir = TRUE;
+	has_xdg_env = FALSE;
+    }
+    vimrc_xdg = concat_fnames(xdg_dir, (char_u *)"vim/vimrc", TRUE);
+
+    if (file_is_readable(vimrc1) || file_is_readable(vimrc2) ||
+	    !file_is_readable(vimrc_xdg))
+	goto theend;
+
+    xdg_rtp = has_xdg_env ? (char_u *)XDG_RUNTIMEPATH
+	: (char_u *)XDG_RUNTIMEPATH_FB;
+
+    if ((opt_idx = findoption((char_u *)"runtimepath")) < 0)
+	goto theend;
+
+    options[opt_idx].def_val[VI_DEFAULT] = xdg_rtp;
+    p_rtp = xdg_rtp;
+
+    if ((opt_idx = findoption((char_u *)"packpath")) < 0)
+	goto theend;
+
+    options[opt_idx].def_val[VI_DEFAULT] = xdg_rtp;
+    p_pp = xdg_rtp;
+
+theend:
+    vim_free(vimrc1);
+    vim_free(vimrc2);
+    vim_free(vimrc_xdg);
+    if (should_free_xdg_dir)
+	vim_free(xdg_dir);
+}
+#endif
+
 /*
  * Expand environment variables and things like "~" for the defaults.
  * If option_expand() returns non-NULL the variable is expanded.  This can
@@ -588,6 +648,7 @@ set_init_1(int clean_arg)
     set_options_default(0);
 
 #ifdef UNIX
+    set_init_xdg_rtp();
     set_init_restricted_mode();
 #endif
 

src/os_unix.h

@@ -236,7 +236,7 @@ typedef struct dsc$descriptor   DESC;
 # ifdef VMS
 # define USR_VIMRC_FILE  "sys$login:.vimrc"
 # else
-#  define USR_VIMRC_FILE "$HOME/.vimrc"
+#  define USR_VIMRC_FILE "~/.vimrc"
 # endif
 #endif
 
@@ -249,6 +249,12 @@ typedef struct dsc$descriptor   DESC;
 # endif
 #endif
 
+#ifndef XDG_VIMRC_FILE
+# define XDG_VIMRC_FILE mch_getenv("XDG_CONFIG_HOME") \
+	? (char_u *)"$XDG_CONFIG_HOME/vim/vimrc" \
+	: (char_u *)"~/.config/vim/vimrc"
+#endif
+
 #if !defined(USR_VIMRC_FILE3) && defined(VMS)
 # define USR_VIMRC_FILE3 "sys$login:_vimrc"
 #endif
@@ -349,13 +355,19 @@ typedef struct dsc$descriptor   DESC;
 #  ifdef RUNTIME_GLOBAL
 #   ifdef RUNTIME_GLOBAL_AFTER
 #    define DFLT_RUNTIMEPATH	"~/.vim," RUNTIME_GLOBAL ",$VIMRUNTIME," RUNTIME_GLOBAL_AFTER ",~/.vim/after"
+#    define XDG_RUNTIMEPATH	"$XDG_CONFIG_HOME/vim," RUNTIME_GLOBAL ",$VIMRUNTIME," RUNTIME_GLOBAL_AFTER "/after,$XDG_CONFIG_HOME/vim/after"
+#    define XDG_RUNTIMEPATH_FB	"~/.config/vim," RUNTIME_GLOBAL ",$VIMRUNTIME," RUNTIME_GLOBAL_AFTER "/after,~/.config/vim/after"
 #    define CLEAN_RUNTIMEPATH	RUNTIME_GLOBAL ",$VIMRUNTIME," RUNTIME_GLOBAL_AFTER
 #   else
 #    define DFLT_RUNTIMEPATH	"~/.vim," RUNTIME_GLOBAL ",$VIMRUNTIME," RUNTIME_GLOBAL "/after,~/.vim/after"
+#    define XDG_RUNTIMEPATH	"$XDG_CONFIG_HOME/vim," RUNTIME_GLOBAL ",$VIMRUNTIME," RUNTIME_GLOBAL "/after,$XDG_CONFIG_HOME/vim/after"
+#    define XDG_RUNTIMEPATH_FB	"~/.config/vim," RUNTIME_GLOBAL ",$VIMRUNTIME," RUNTIME_GLOBAL "/after,~/.config/vim/after"
 #    define CLEAN_RUNTIMEPATH	RUNTIME_GLOBAL ",$VIMRUNTIME," RUNTIME_GLOBAL "/after"
 #   endif
 #  else
 #   define DFLT_RUNTIMEPATH	"~/.vim,$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after,~/.vim/after"
+#   define XDG_RUNTIMEPATH	"$XDG_CONFIG_HOME/vim,$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after,$XDG_CONFIG_HOME/vim/after"
+#   define XDG_RUNTIMEPATH_FB	"~/.config/vim,$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after,~/.config/vim/after"
 #   define CLEAN_RUNTIMEPATH	"$VIM/vimfiles,$VIMRUNTIME,$VIM/vimfiles/after"
 #  endif
 # endif

src/testdir/Make_all.mak

@@ -331,6 +331,7 @@ NEW_TESTS = \
 	test_wnext \
 	test_wordcount \
 	test_writefile \
+	test_xdg \
 	test_xxd \
 	test_alot_latin \
 	test_alot_utf8 \
@@ -564,6 +565,7 @@ NEW_TESTS_RES = \
 	test_winfixbuf.res \
 	test_wordcount.res \
 	test_writefile.res \
+	test_xdg.res \
 	test_xxd.res \
 	test_alot_latin.res \
 	test_alot_utf8.res \

src/testdir/dumps/Test_xdg_1.dump

@@ -0,0 +1,20 @@
+|~+0#4040ff13#ffffff0| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|r+0#0000000&|c|_|o|n|e| @16|o|n|e| @48
+|r|c| @20|.|v|i|m|r|c| @45
+|P+0#00e0003&|r|e|s@1| |E|N|T|E|R| |o|r| |t|y|p|e| |c|o|m@1|a|n|d| |t|o| |c|o|n|t|i|n|u|e> +0#0000000&@35

src/testdir/dumps/Test_xdg_2.dump

@@ -0,0 +1,20 @@
+|~+0#4040ff13#ffffff0| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|r+0#0000000&|c|_|t|w|o| @16|t|w|o| @48
+|r|c| @20|.|v|i|m|/|v|i|m|r|c| @41
+|P+0#00e0003&|r|e|s@1| |E|N|T|E|R| |o|r| |t|y|p|e| |c|o|m@1|a|n|d| |t|o| |c|o|n|t|i|n|u|e> +0#0000000&@35

src/testdir/dumps/Test_xdg_3.dump

@@ -0,0 +1,20 @@
+|~+0#4040ff13#ffffff0| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|r+0#0000000&|c|_|t|h|r|e@1| @14|t|h|r|e@1| @46
+|r|c| @20|.|c|o|n|f|i|g|/|v|i|m|/|v|i|m|r|c| @34
+|P+0#00e0003&|r|e|s@1| |E|N|T|E|R| |o|r| |t|y|p|e| |c|o|m@1|a|n|d| |t|o| |c|o|n|t|i|n|u|e> +0#0000000&@35

src/testdir/dumps/Test_xdg_4.dump

@@ -0,0 +1,20 @@
+|~+0#4040ff13#ffffff0| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|~| @73
+|r+0#0000000&|c|_|f|o|u|r| @15|f|o|u|r| @47
+|r|c| @20|x|d|g|/|v|i|m|/|v|i|m|r|c| @38
+|P+0#00e0003&|r|e|s@1| |E|N|T|E|R| |o|r| |t|y|p|e| |c|o|m@1|a|n|d| |t|o| |c|o|n|t|i|n|u|e> +0#0000000&@35