bdnav: warn on dropped MPLS, dedupe be_u16, pin SET taint test

src/bdnav/index.rs

@@ -3,6 +3,8 @@
 //! documented binary format, never executed: every field is bounds-checked and
 //! any malformed input yields `None` (the nav resolver then abstains).
 
+use super::be_u16;
+
 /// One playback/title object in `index.bdmv`.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub(crate) enum PlaybackObj {
@@ -29,9 +31,6 @@ const OBJ_LEN: usize = 12;
 /// Sanity cap on the title count (real discs have well under this).
 const MAX_TITLES: usize = 4096;
 
-fn be_u16(d: &[u8], o: usize) -> Option<u16> {
-    Some(u16::from_be_bytes([*d.get(o)?, *d.get(o + 1)?]))
-}
 fn be_u32(d: &[u8], o: usize) -> Option<u32> {
     Some(u32::from_be_bytes([
         *d.get(o)?,

src/bdnav/mobj.rs

@@ -7,6 +7,8 @@
 //! byte 50. Each object is `flags`(1) + reserved(1) + `num_cmds`(u16) followed
 //! by `num_cmds` 12-byte navigation commands.
 
+use super::be_u16;
+
 // One decoded 12-byte navigation command.
 #[derive(Debug, Clone, Copy)]
 pub(crate) struct Cmd {
@@ -36,10 +38,6 @@ const CMD_LEN: usize = 12;
 /// separate cap would be dead code.
 const MAX_OBJECTS: usize = 4096;
 
-fn be_u16(d: &[u8], o: usize) -> Option<u16> {
-    Some(u16::from_be_bytes([*d.get(o)?, *d.get(o + 1)?]))
-}
-
 /// Decode one 12-byte command. Caller guarantees `b.len() == 12`.
 fn decode_cmd(b: &[u8]) -> Cmd {
     let (b0, b1, b2, b3) = (b[0], b[1], b[2], b[3]);

src/bdnav/mod.rs

@@ -14,6 +14,10 @@ pub(crate) mod vm;
 use crate::sector::SectorSource;
 use crate::udf::UdfFs;
 
+pub(super) fn be_u16(d: &[u8], o: usize) -> Option<u16> {
+    Some(u16::from_be_bytes([*d.get(o)?, *d.get(o + 1)?]))
+}
+
 // Resolve the playlist id First-Play navigation plays as the feature, among ids the caller
 // marks as feature candidates (`is_feature_candidate`). Returns `None` for BD-J discs,
 // malformed nav data, or non-convergence.

src/bdnav/vm.rs

@@ -674,6 +674,17 @@ mod tests {
         assert_eq!(resolve(&index, &mobjs, &|_| true), None);
     }
 
+    #[test]
+    fn set_from_rnd_source_taints_destination() {
+        // GPR0 = RND; GPR1 (clean) += GPR0 (register src); PlayPL GPR1 must abstain.
+        let rnd = set_imm(0x08, 0, 10);
+        let add = cmd((2 << 5) | (2 << 3), 0x00, 0, 0x03, 1, 0);
+        let d = build(&[&[rnd, add, play_pl_reg(1), play_pl(1)]]);
+        let mobjs = mobj::parse(&d).unwrap();
+        let index = idx(PlaybackObj::Hdmv { id_ref: 0 }, vec![]);
+        assert_eq!(resolve(&index, &mobjs, &|_| true), None);
+    }
+
     #[test]
     fn playpl_operand_over_16_bits_is_not_a_playlist_id() {
         // 0x1_0001 must not alias playlist 1; the VM falls through to 800.

src/disc/bluray.rs

@@ -62,8 +62,18 @@ impl Disc {
         filename: &str,
         data: &[u8],
     ) -> Result<Option<DiscTitle>> {
-        let Ok(parsed) = mpls::parse(data) else {
-            return Ok(None);
+        let parsed = match mpls::parse(data) {
+            Ok(p) => p,
+            Err(e) => {
+                // Real code, matching the CLPI path: a malformed playlist is
+                // dropped, but never silently.
+                tracing::warn!(
+                    target: "freemkv::disc",
+                    playlist = ?filename,
+                    "E{}", e.code()
+                );
+                return Ok(None);
+            }
         };
 
         // Calculate duration from play items
@@ -665,11 +675,16 @@ mod tests {
         let mut disc = MemDisc::new();
         let udf = make_min_fs(&mut disc);
         let junk = vec![0u8; 100];
-        assert!(
-            Disc::parse_playlist(&mut disc, &udf, "00001.mpls", &junk)
-                .expect("scan")
-                .is_none()
-        );
+        let (t, events) = crate::testlog::capture(|| {
+            Disc::parse_playlist(&mut disc, &udf, "00001.mpls", &junk).expect("scan")
+        });
+        assert!(t.is_none());
+        let line = events
+            .iter()
+            .find(|e| e.target == "freemkv::disc")
+            .unwrap_or_else(|| panic!("a dropped playlist must be logged; got {events:?}"));
+        assert_eq!(line.level, tracing::Level::WARN);
+        assert_eq!(line.message(), format!("E{}", crate::error::E_MPLS_PARSE));
     }
 
     /// Build the minimal fixture: an empty `BDMV/` directory (no STREAM,