labels: one control-character filter for disc-authored titles

bdmt title and description text kept raw control characters from CDATA and plain bodies,
so a disc could put a terminal escape sequence into a shown title or a file name. It now
goes through the same filter as the Blu-ray di:name title.

src/disc/bluray.rs

@@ -511,11 +511,9 @@ impl Disc {
                             if let Some(end) = xml[s..].find("</di:name>") {
                                 // Disc-authored text reaches terminals and file names:
                                 // control characters (decoded from `&#27;` too) are dropped.
-                                let title: String = xml_text_decode(xml[s..s + end].trim())
-                                    .chars()
-                                    .filter(|c| !c.is_control())
-                                    .collect();
-                                let title = title.trim().to_string();
+                                let title = crate::labels::display_text(&xml_text_decode(
+                                    xml[s..s + end].trim(),
+                                ));
                                 if !title.is_empty() && !crate::labels::is_placeholder_title(&title)
                                 {
                                     return Some(title);

src/labels/bdmt.rs

@@ -182,10 +182,10 @@ fn field_text(raw: &str) -> Option<String> {
         .strip_prefix("<![CDATA[")
         .and_then(|r| r.strip_suffix("]]>"))
     {
-        Some(inner) if !inner.contains("]]>") => inner.trim().to_string(),
+        Some(inner) if !inner.contains("]]>") => display_text(inner),
         Some(_) => return None,
         None if looks_like_xml(raw) => return None,
-        None => decode_entities(raw),
+        None => display_text(&decode_entities(raw)),
     };
     if out.is_empty() || looks_like_xml(&out) {
         return None;
@@ -233,6 +233,13 @@ fn decode_entities(s: &str) -> String {
     out
 }
 
+/// Disc-authored text as shown and put in file names: control characters (an escape
+/// sequence, a raw newline) dropped, then trimmed.
+pub(crate) fn display_text(s: &str) -> String {
+    let kept: String = s.chars().filter(|c| !c.is_control()).collect();
+    kept.trim().to_string()
+}
+
 /// True for the generic `Blu-ray` some discs (Warner's non-English bdmt files) put where
 /// the title belongs: not a title, so callers skip to the next candidate.
 pub(crate) fn is_placeholder_title(title: &str) -> bool {
@@ -322,6 +329,18 @@ mod tests {
         assert!(d.expect("desc").len() <= MAX_BDMT_TEXT);
     }
 
+    // A title or description, CDATA or plain, keeps no control character (a terminal escape
+    // sequence, a raw newline), as the Blu-ray di:name path does not.
+    #[test]
+    fn disc_text_drops_control_characters() {
+        let xml = "<d><di:name><![CDATA[Movie\x1b]0;pwned\x07]]></di:name>\
+                   <di:description>Line\x1b[2Jone\ntwo</di:description></d>";
+        let (t, d, _) = parse_bdmt_xml(xml).expect("parse");
+        assert_eq!(t, "Movie]0;pwned");
+        assert_eq!(d.as_deref(), Some("Line[2Jonetwo"));
+        assert_eq!(display_text(" \x1bA\tB "), "AB");
+    }
+
     #[test]
     fn cap_text_cuts_on_a_char_boundary() {
         let s = format!("aa{}", "\u{4e16}".repeat(400));

src/labels/mod.rs

@@ -34,7 +34,7 @@ use crate::udf::UdfFs;
 // disc-level metadata via `labels::DiscMetadata`. The module itself
 // stays private — analyze() drives the parse path.
 pub use bdmt::DiscMetadata;
-pub(crate) use bdmt::is_placeholder_title;
+pub(crate) use bdmt::{display_text, is_placeholder_title};
 
 // Re-exported via crate::disc — the public API surfaces these next to
 // AudioStream/SubtitleStream so callers can map purpose/qualifier to display