feat(bls): read the loader.conf preferred key and strip quotes

crates/bls/src/lib.rs

@@ -846,6 +846,27 @@ mod tests {
         assert_eq!(boot_path(""), "/");
     }
 
+    #[test]
+    fn loader_conf_reads_preferred() {
+        let conf = LoaderConf::parse("preferred fedora-*\n");
+        assert_eq!(conf.preferred.as_deref(), Some("fedora-*"));
+        assert!(conf.warnings.is_empty());
+    }
+
+    #[test]
+    fn loader_conf_strips_matching_quotes() {
+        let conf = LoaderConf::parse("default \"foo*\"\npreferred 'bar'\ntimeout \"3\"\n");
+        assert_eq!(conf.default.as_deref(), Some("foo*"));
+        assert_eq!(conf.preferred.as_deref(), Some("bar"));
+        assert_eq!(conf.timeout, Some(LoaderTimeout::Seconds(3)));
+    }
+
+    #[test]
+    fn loader_conf_keeps_unmatched_quotes() {
+        let conf = LoaderConf::parse("default \"foo\n");
+        assert_eq!(conf.default.as_deref(), Some("\"foo"));
+    }
+
     #[test]
     fn loader_conf_empty_has_no_settings() {
         let conf = LoaderConf::parse("");

crates/bls/src/loader_conf.rs

@@ -36,12 +36,28 @@ impl LoaderTimeout {
 pub struct LoaderConf {
     /// A glob pattern that selects the default entry, or `@saved`.
     pub default: Option<String>,
+    /// A glob pattern that selects the preferred entry, or `@saved`. Unlike `default`, an entry
+    /// with no boot counter tries left is not used.
+    pub preferred: Option<String>,
     /// How long to show the boot menu.
     pub timeout: Option<LoaderTimeout>,
     /// Problems found while parsing, such as keys that are not supported.
     pub warnings: Vec<String>,
 }
 
+/// Removes one pair of matching single or double quotes around `value`.
+fn unquote(value: &str) -> &str {
+    for quote in ['"', '\''] {
+        if let Some(inner) = value
+            .strip_prefix(quote)
+            .and_then(|rest| rest.strip_suffix(quote))
+        {
+            return inner;
+        }
+    }
+    value
+}
+
 impl LoaderConf {
     /// Parses the `input` as a `loader.conf` file. Parsing never fails, as a bad setting
     /// should not prevent booting. Anything that is ignored is described in `warnings`.
@@ -59,21 +75,22 @@ impl LoaderConf {
             }
 
             let (key, value) = match line.split_once(char::is_whitespace) {
-                Some((key, value)) => (key, value.trim()),
+                Some((key, value)) => (key, unquote(value.trim())),
                 None => (line, ""),
             };
 
             match key {
                 "default" if !value.is_empty() => conf.default = Some(value.to_string()),
+                "preferred" if !value.is_empty() => conf.preferred = Some(value.to_string()),
                 "timeout" => match LoaderTimeout::parse(value) {
                     Some(timeout) => conf.timeout = Some(timeout),
                     None => conf
                         .warnings
                         .push(format!("ignoring invalid loader.conf timeout '{}'", value)),
                 },
-                "default" => conf
+                "default" | "preferred" => conf
                     .warnings
-                    .push("ignoring loader.conf default without a value".to_string()),
+                    .push(format!("ignoring loader.conf {} without a value", key)),
                 _ => conf
                     .warnings
                     .push(format!("ignoring unsupported loader.conf key '{}'", key)),