fix(bls): write boot counters systemd can read and match systemd on small details

Do not pad the boot counter digits or cap the tries done counter, as
systemd-bless-boot reads a counter with a leading zero as octal and
systemd-boot never writes one. A profile only selects a profile when it
is a number above zero, an unterminated bracket in a pattern matches
nothing, and files that start with auto- are ignored in any case and for
unified kernel images too. The saved entry is compared ignoring case, and
entry settings are only expanded for sources that are looked at.

crates/parsing/src/lib.rs

@@ -216,9 +216,11 @@ enum FnmatchToken {
     Star,
     /// `[...]`, which matches a byte in any of the inclusive ranges, already lowercased.
     Class(Vec<(u8, u8)>),
+    /// A pattern that can't match anything, such as one with an unterminated `[`.
+    Never,
 }
 
-/// Splits `pattern` into tokens. An unterminated `[` matches itself.
+/// Splits `pattern` into tokens. An unterminated `[` never matches, as in systemd-boot.
 fn fnmatch_tokens(pattern: &[u8]) -> Vec<FnmatchToken> {
     let mut tokens = Vec::new();
     let mut index = 0;
@@ -250,7 +252,7 @@ fn fnmatch_tokens(pattern: &[u8]) -> Vec<FnmatchToken> {
                     tokens.push(FnmatchToken::Class(ranges));
                     index += length + 1;
                 }
-                _ => tokens.push(FnmatchToken::Literal(b'[')),
+                _ => tokens.push(FnmatchToken::Never),
             },
             other => tokens.push(FnmatchToken::Literal(other.to_ascii_lowercase())),
         }
@@ -282,7 +284,7 @@ pub fn fnmatch_ignore_case(pattern: &str, text: &str) -> bool {
                 p += 1;
                 continue;
             }
-            None => false,
+            Some(FnmatchToken::Never) | None => false,
         };
         if matched {
             p += 1;
@@ -711,9 +713,10 @@ mod tests {
     }
 
     #[test]
-    fn fnmatch_unterminated_bracket_is_a_literal() {
-        assert!(fnmatch_ignore_case("a[b", "a[b"));
+    fn fnmatch_unterminated_bracket_matches_nothing() {
+        assert!(!fnmatch_ignore_case("a[b", "a[b"));
         assert!(!fnmatch_ignore_case("a[b", "ab"));
+        assert!(!fnmatch_ignore_case("a[", "a["));
     }
 
     #[test]