Fix shell escaping in getting current env

Credit to Dario Weißer for bringing this to our attention.

Author: ConradIrwin

crates/util/src/shell_env.rs

@@ -94,8 +94,13 @@ async fn capture_unix(
         _ => command.args(["-i", "-c"]),
     };
 
+    let dir_str = directory.to_string_lossy();
+    let safe_dir = shell_kind
+        .try_quote(&dir_str)
+        .context("unexpected null in directory name")?;
+
     // cd into the directory, triggering directory specific side-effects (asdf, direnv, etc)
-    command_string.push_str(&format!("cd '{}';", directory.display()));
+    command_string.push_str(&format!("cd {};", safe_dir));
     if let Some(prefix) = shell_kind.command_prefix() {
         command_string.push(prefix);
     }
@@ -172,7 +177,7 @@ async fn capture_windows(
         shell_kind
             .try_quote(value)
             .map(|quoted| quoted.into_owned())
-            .unwrap_or_else(|| value.to_owned())
+            .context("unexpected null in directory name")
     };
     let mut cmd = crate::command::new_command(shell_path);
     cmd.args(args);
@@ -183,8 +188,8 @@ async fn capture_windows(
         | ShellKind::Fish
         | ShellKind::Xonsh
         | ShellKind::Posix => {
-            let quoted_directory = quote_for_shell(&directory_string);
-            let quoted_zed_path = quote_for_shell(&zed_path_string);
+            let quoted_directory = quote_for_shell(&directory_string)?;
+            let quoted_zed_path = quote_for_shell(&zed_path_string)?;
             cmd.args([
                 "-l",
                 "-i",