Improve handling of invalid comment in fromRfc2822 function

Author: fabon-f

src/datetime/fromRfc2822.test.ts

@@ -113,6 +113,15 @@ test("comment", () => {
 	).toEqual(Temporal.Instant.from("2024-06-07T01:23:45Z"));
 });
 
+test("unbalanced comment", () => {
+	expect(() =>
+		fromRfc2822("07 Jun 2024 01:23:45 +0000 (comment", Temporal.Instant),
+	).toThrowError();
+	expect(() =>
+		fromRfc2822("07 Jun 2024 (comment)) 01:23:45 +0000", Temporal.Instant),
+	).toThrowError();
+});
+
 test("invalid day of week", () => {
 	expect(() => {
 		fromRfc2822("Mot, 07 Jun 2024 01:23:45 +0900", Temporal.PlainDateTime);

src/datetime/fromRfc2822.ts

@@ -28,8 +28,14 @@ function removeComment(str: string) {
 				// comment ended
 				lastNonCommentStarted = m.index + 1;
 			}
+			if (commentNestLevel < 0) {
+				throw new Error("Unbalanced nested comment");
+			}
 		}
 	}
+	if (commentNestLevel !== 0) {
+		throw new Error("Unbalanced nested comment");
+	}
 	return res;
 }