nix-profile{,-daemon}.fish: Do not source twice

In order for the script not be sourced multiple times by the same shell
instance, `__ETC_PROFILE_NIX_SOURCED` needs to be set with a `--global`
flag.

Both files are almost identical.  And style differences make it harder
to see what is actually different and keep them in sync, when it is
required.

scripts/nix-profile-daemon.fish.in

@@ -1,3 +1,13 @@
+# Only execute this file once per shell.
+if test -z "$HOME" || \
+    test -n "$__ETC_PROFILE_NIX_SOURCED"
+    exit
+end
+
+set --global __ETC_PROFILE_NIX_SOURCED 1
+
+# Local helpers
+
 function add_path --argument-names new_path
     if type -q fish_add_path
         # fish 3.2.0 or newer
@@ -10,13 +20,7 @@ function add_path --argument-names new_path
     end
 end
 
-# Only execute this file once per shell.
-if test -n "$__ETC_PROFILE_NIX_SOURCED"
-    exit
-end
-
-set __ETC_PROFILE_NIX_SOURCED 1
-
+# Main configuration
 set --export NIX_PROFILES "@localstatedir@/nix/profiles/default $HOME/.nix-profile"
 
 # Populate bash completions, .desktop files, etc
@@ -54,4 +58,6 @@ end
 add_path "@localstatedir@/nix/profiles/default/bin"
 add_path "$HOME/.nix-profile/bin"
 
+# Cleanup
+
 functions -e add_path

scripts/nix-profile.fish.in

@@ -1,3 +1,13 @@
+# Only execute this file once per shell.
+if test -z "$HOME" || test -z "$USER" || \
+    test -n "$__ETC_PROFILE_NIX_SOURCED"
+    exit
+end
+
+set --global __ETC_PROFILE_NIX_SOURCED 1
+
+# Local helpers
+
 function add_path --argument-names new_path
     if type -q fish_add_path
         # fish 3.2.0 or newer
@@ -10,50 +20,51 @@ function add_path --argument-names new_path
     end
 end
 
-if test -n "$HOME" && test -n "$USER"
+# Main configuration
 
-    # Set up the per-user profile.
+# Set up the per-user profile.
 
-    set NIX_LINK $HOME/.nix-profile
+set NIX_LINK $HOME/.nix-profile
 
-    # Set up environment.
-    # This part should be kept in sync with nixpkgs:nixos/modules/programs/environment.nix
-    set --export NIX_PROFILES "@localstatedir@/nix/profiles/default $HOME/.nix-profile"
-
-    # Populate bash completions, .desktop files, etc
-    if test -z "$XDG_DATA_DIRS"
-        # According to XDG spec the default is /usr/local/share:/usr/share, don't set something that prevents that default
-        set --export XDG_DATA_DIRS "/usr/local/share:/usr/share:$NIX_LINK/share:/nix/var/nix/profiles/default/share"
-    else
-        set --export XDG_DATA_DIRS "$XDG_DATA_DIRS:$NIX_LINK/share:/nix/var/nix/profiles/default/share"
-    end
+# Set up environment.
+# This part should be kept in sync with nixpkgs:nixos/modules/programs/environment.nix
+set --export NIX_PROFILES "@localstatedir@/nix/profiles/default $HOME/.nix-profile"
 
-    # Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
-    if test -n "$NIX_SSH_CERT_FILE"
-        : # Allow users to override the NIX_SSL_CERT_FILE
-    else if test -e /etc/ssl/certs/ca-certificates.crt # NixOS, Ubuntu, Debian, Gentoo, Arch
-        set --export NIX_SSL_CERT_FILE /etc/ssl/certs/ca-certificates.crt
-    else if test -e /etc/ssl/ca-bundle.pem # openSUSE Tumbleweed
-        set --export NIX_SSL_CERT_FILE /etc/ssl/ca-bundle.pem
-    else if test -e /etc/ssl/certs/ca-bundle.crt # Old NixOS
-        set --export NIX_SSL_CERT_FILE /etc/ssl/certs/ca-bundle.crt
-    else if test -e /etc/pki/tls/certs/ca-bundle.crt # Fedora, CentOS
-        set --export NIX_SSL_CERT_FILE /etc/pki/tls/certs/ca-bundle.crt
-    else if test -e "$NIX_LINK/etc/ssl/certs/ca-bundle.crt" # fall back to cacert in Nix profile
-        set --export NIX_SSL_CERT_FILE "$NIX_LINK/etc/ssl/certs/ca-bundle.crt"
-    else if test -e "$NIX_LINK/etc/ca-bundle.crt" # old cacert in Nix profile
-        set --export NIX_SSL_CERT_FILE "$NIX_LINK/etc/ca-bundle.crt"
-    end
+# Populate bash completions, .desktop files, etc
+if test -z "$XDG_DATA_DIRS"
+    # According to XDG spec the default is /usr/local/share:/usr/share, don't set something that prevents that default
+    set --export XDG_DATA_DIRS "/usr/local/share:/usr/share:$NIX_LINK/share:/nix/var/nix/profiles/default/share"
+else
+    set --export XDG_DATA_DIRS "$XDG_DATA_DIRS:$NIX_LINK/share:/nix/var/nix/profiles/default/share"
+end
 
-    # Only use MANPATH if it is already set. In general `man` will just simply
-    # pick up `.nix-profile/share/man` because is it close to `.nix-profile/bin`
-    # which is in the $PATH. For more info, run `manpath -d`.
-    if set --query MANPATH
-      set --export --prepend --path MANPATH "$NIX_LINK/share/man"
-    end
+# Set $NIX_SSL_CERT_FILE so that Nixpkgs applications like curl work.
+if test -n "$NIX_SSH_CERT_FILE"
+    : # Allow users to override the NIX_SSL_CERT_FILE
+else if test -e /etc/ssl/certs/ca-certificates.crt # NixOS, Ubuntu, Debian, Gentoo, Arch
+    set --export NIX_SSL_CERT_FILE /etc/ssl/certs/ca-certificates.crt
+else if test -e /etc/ssl/ca-bundle.pem # openSUSE Tumbleweed
+    set --export NIX_SSL_CERT_FILE /etc/ssl/ca-bundle.pem
+else if test -e /etc/ssl/certs/ca-bundle.crt # Old NixOS
+    set --export NIX_SSL_CERT_FILE /etc/ssl/certs/ca-bundle.crt
+else if test -e /etc/pki/tls/certs/ca-bundle.crt # Fedora, CentOS
+    set --export NIX_SSL_CERT_FILE /etc/pki/tls/certs/ca-bundle.crt
+else if test -e "$NIX_LINK/etc/ssl/certs/ca-bundle.crt" # fall back to cacert in Nix profile
+    set --export NIX_SSL_CERT_FILE "$NIX_LINK/etc/ssl/certs/ca-bundle.crt"
+else if test -e "$NIX_LINK/etc/ca-bundle.crt" # old cacert in Nix profile
+    set --export NIX_SSL_CERT_FILE "$NIX_LINK/etc/ca-bundle.crt"
+end
 
-    add_path "$NIX_LINK/bin"
-    set --erase NIX_LINK
+# Only use MANPATH if it is already set. In general `man` will just simply
+# pick up `.nix-profile/share/man` because is it close to `.nix-profile/bin`
+# which is in the $PATH. For more info, run `manpath -d`.
+if set --query MANPATH
+    set --export --prepend --path MANPATH "$NIX_LINK/share/man"
 end
 
+add_path "$NIX_LINK/bin"
+set --erase NIX_LINK
+
+# Cleanup
+
 functions -e add_path