Fix rustup-init failure to read ZDOTDIR from zsh when SHELL is not zsh (#3584)

Author: ericswanson-dfinity

src/cli/self_update/shell.rs

@@ -166,7 +166,7 @@ impl Zsh {
             }
         } else {
             match std::process::Command::new("zsh")
-                .args(["-c", "'echo $ZDOTDIR'"])
+                .args(["-c", "echo -n $ZDOTDIR"])
                 .output()
             {
                 Ok(io) if !io.stdout.is_empty() => Ok(PathBuf::from(OsStr::from_bytes(&io.stdout))),

tests/suite/cli_paths.rs

@@ -144,6 +144,45 @@ export PATH="$HOME/apple/bin"
         });
     }
 
+    #[test]
+    fn install_with_zdotdir_from_calling_zsh() {
+        // This test requires that zsh is callable.
+        if std::process::Command::new("zsh")
+            .arg("-c")
+            .arg("true")
+            .status()
+            .is_err()
+        {
+            return;
+        }
+        clitools::test(Scenario::Empty, &|config| {
+            let zdotdir = tempfile::Builder::new()
+                .prefix("zdotdir")
+                .tempdir()
+                .unwrap();
+            let rc = zdotdir.path().join(".zshenv");
+            raw::write_file(&rc, FAKE_RC).unwrap();
+
+            // If $SHELL doesn't include "zsh", Zsh::zdotdir() will call zsh to obtain $ZDOTDIR.
+            // ZDOTDIR could be set directly in the environment, but having ~/.zshenv set
+            // ZDOTDIR is a normal setup, and ensures that the value came from calling zsh.
+            let home_zshenv = config.homedir.join(".zshenv");
+            let export_zdotdir = format!(
+                "export ZDOTDIR=\"{}\"\n",
+                zdotdir.path().as_os_str().to_str().unwrap()
+            );
+            raw::write_file(&home_zshenv, &export_zdotdir).unwrap();
+
+            let mut cmd = clitools::cmd(config, "rustup-init", &INIT_NONE[1..]);
+            cmd.env("SHELL", "/bin/sh");
+            assert!(cmd.output().unwrap().status.success());
+
+            let new_rc = fs::read_to_string(&rc).unwrap();
+            let expected = FAKE_RC.to_owned() + &source(config.cargodir.display(), POSIX_SH);
+            assert_eq!(new_rc, expected);
+        });
+    }
+
     #[test]
     fn install_adds_path_to_rc_just_once() {
         clitools::test(Scenario::Empty, &|config| {