Remove scripted XDG_CONFIG_HOME uses

Cleaned up the code to no longer replicate in fishscript what fish
already does (and caches to boot) in C++ in setting up the paths to the
user configuration directory.

Also introduced a `$__fish_user_data_dir` instead of the sporadic
definitions of `$userdatadir` that may or may not go through
`XDG_DATA_HOME`.

share/config.fish

@@ -62,18 +62,6 @@ end
 # unless they already exist
 #
 
-set -g __fish_config_dir ~/.config/fish
-
-if set -q XDG_CONFIG_HOME
-    set __fish_config_dir $XDG_CONFIG_HOME/fish
-end
-
-set -l userdatadir ~/.local/share
-
-if set -q XDG_DATA_HOME
-    set userdatadir $XDG_DATA_HOME
-end
-
 # __fish_data_dir, __fish_sysconf_dir, __fish_help_dir, __fish_bin_dir
 # are expected to have been set up by read_init from fish.cpp
 
@@ -98,7 +86,7 @@ if not contains -- $__fish_data_dir/functions $fish_function_path
 end
 
 if not set -q fish_complete_path
-    set fish_complete_path $__fish_config_dir/completions $__fish_sysconf_dir/completions $__extra_completionsdir $__fish_data_dir/completions $userdatadir/fish/generated_completions
+    set fish_complete_path $__fish_config_dir/completions $__fish_sysconf_dir/completions $__extra_completionsdir $__fish_data_dir/completions $__fish_user_data_dir/generated_completions
 end
 
 if not contains -- $__fish_data_dir/completions $fish_complete_path
@@ -109,7 +97,7 @@ end
 function :
     # no-op function for compatibility with sh, bash, and others.
     # Often used to insert a comment into a chain of commands without having
-	# it eat up the remainder of the line, handy in Makefiles.
+    # it eat up the remainder of the line, handy in Makefiles.
 end
 
 #

share/functions/__fish_config_interactive.fish

@@ -21,12 +21,6 @@ function __fish_config_interactive -d "Initializations that should be performed
     set -g __fish_config_interactive_done
     set -g __fish_active_key_bindings
 
-    # Set the correct user data directory
-    set -l userdatadir ~/.local/share
-    if set -q XDG_DATA_HOME
-        set userdatadir $XDG_DATA_HOME
-    end
-
     if not set -q fish_greeting
         set -l line1 (_ 'Welcome to fish, the friendly interactive shell')
         set -l line2 ''
@@ -97,7 +91,7 @@ function __fish_config_interactive -d "Initializations that should be performed
     #
     # Don't do this if we're being invoked as part of running unit tests.
     if not set -q FISH_UNIT_TESTS_RUNNING
-        if not test -d $userdatadir/fish/generated_completions
+        if not test -d $__fish_user_data_dir/generated_completions
             # Generating completions from man pages needs python (see issue #3588).
 
             # We cannot simply do `fish_update_completions &` because it is a function.

src/env.cpp

@@ -67,6 +67,8 @@
 #define FISH_SYSCONFDIR_VAR L"__fish_sysconf_dir"
 #define FISH_HELPDIR_VAR L"__fish_help_dir"
 #define FISH_BIN_DIR L"__fish_bin_dir"
+#define FISH_CONFIG_DIR L"__fish_config_dir"
+#define FISH_USER_DATA_DIR L"__fish_user_data_dir"
 
 /// At init, we read all the environment variables from this array.
 extern char **environ;
@@ -877,6 +879,14 @@ void env_init(const struct config_paths_t *paths /* or NULL */) {
         env_set_one(FISH_BIN_DIR, ENV_GLOBAL, paths->bin);
     }
 
+    wcstring user_config_dir;
+    path_get_config(user_config_dir);
+    env_set_one(FISH_CONFIG_DIR, ENV_GLOBAL, user_config_dir);
+
+    wcstring user_data_dir;
+    path_get_data(user_data_dir);
+    env_set_one(FISH_USER_DATA_DIR, ENV_GLOBAL, user_data_dir);
+
     init_locale();
     init_curses();
     init_input();