Install into a subdir of ~/.local/share/fish

Otherwise you have all the gunk next to the history etc.

So we isolate it in ~/.local/share/fish/install/.

build.rs

@@ -194,6 +194,13 @@ fn setup_paths() {
  rsconf::set_env_value("DATADIR", datadir.to_str().unwrap());
  rsconf::rebuild_if_env_changed("DATADIR");
 
+ let datadir_subdir = if prefix_from_home {
+ "fish/install"
+ } else {
+ "fish"
+ };
+ rsconf::set_env_value("DATADIR_SUBDIR", datadir_subdir);
+
  let bindir = get_path("BINDIR", "bin/", prefix.clone());
  rsconf::set_env_value("BINDIR", bindir.to_str().unwrap());
  rsconf::rebuild_if_env_changed("BINDIR");

src/bin/fish.rs

@@ -71,6 +71,7 @@ use std::{env, ops::ControlFlow};
 
 const DOC_DIR: &str = env!("DOCDIR");
 const DATA_DIR: &str = env!("DATADIR");
+const DATA_DIR_SUBDIR: &str = env!("DATADIR_SUBDIR");
 const SYSCONF_DIR: &str = env!("SYSCONFDIR");
 const BIN_DIR: &str = env!("BINDIR");
 
@@ -276,7 +277,7 @@ fn determine_config_directory_paths(argv0: impl AsRef<Path>) -> ConfigPaths {
  // Fall back to what got compiled in.
  FLOG!(config, "Using compiled in paths:");
  paths = ConfigPaths {
- data: PathBuf::from(DATA_DIR).join("fish"),
+ data: PathBuf::from(DATA_DIR).join(DATA_DIR_SUBDIR),
  sysconf: PathBuf::from(SYSCONF_DIR).join("fish"),
  doc: DOC_DIR.into(),
  bin: BIN_DIR.into(),