fixup! Strip Unicode Cf characters in PrintableString

Author: tnull

lightning-types/src/string.rs

@@ -67,7 +67,7 @@ fn is_format_char(c: char) -> bool {
 			| 0xFFF9..=0xFFFB
 			| 0x110BD
 			| 0x110CD
-			| 0x13430..=0x13440
+			| 0x13430..=0x1343F
 			| 0x1BCA0..=0x1BCA3
 			| 0x1D173..=0x1D17A
 			| 0xE0001
@@ -101,5 +101,12 @@ mod tests {
 			"PrintableString left a U+202E RLO override in its output: {:?}",
 			rendered
 		);
+
+		// U+13440 is in the Egyptian Hieroglyph Format Controls block, but its
+		// general category is `Mn`, not `Cf`, so the `Cf` range ends at U+1343F.
+		assert_eq!(
+			format!("{}", PrintableString("x\u{1343F}y\u{13440}z")),
+			"x\u{FFFD}y\u{13440}z"
+		);
 	}
 }