tests: key-api guard catches UFCS calls, correct pass_n header; examples: valid NDJSON errors

examples/corpus_titledump.rs

@@ -43,9 +43,9 @@ fn dump_one(path: &Path) -> String {
         Ok(r) => r,
         Err(e) => {
             return format!(
-                "{{\"iso\":{},\"error\":\"open: {:?}\"}}",
+                "{{\"iso\":{},\"error\":{}}}",
                 jstr(name),
-                format!("{e}")
+                jstr(&format!("open: {e}"))
             );
         }
     };
@@ -55,9 +55,9 @@ fn dump_one(path: &Path) -> String {
         Ok(d) => d,
         Err(e) => {
             return format!(
-                "{{\"iso\":{},\"error\":\"scan: {}\"}}",
+                "{{\"iso\":{},\"error\":{}}}",
                 jstr(name),
-                jstr(&format!("{e}"))
+                jstr(&format!("scan: {e}"))
             );
         }
     };

tests/legacy_key_api_guard.rs

@@ -15,9 +15,9 @@ use std::path::{Path, PathBuf};
 
 /// §2.2, the libfreemkv row of the structural guards.
 const BANNED: &[&str] = &[
-    ".get_unit_keys(",
-    ".get_fmts_indexes(",
-    ".resolve_unit_keys(",
+    "get_unit_keys(",
+    "get_fmts_indexes(",
+    "resolve_unit_keys(",
     "decrypt_with(",
     "AacsKeyMap::from_ranges",
     "with_key_map(",
@@ -154,6 +154,17 @@ fn hits(rel: &str, src: &str) -> Vec<(usize, &'static str)> {
             if code[k..k + t.len()] != t[..] || inside(k) {
                 continue;
             }
+            // The three trait ops are banned as calls (method or UFCS), not as `fn` items.
+            let method = matches!(
+                tok,
+                "get_unit_keys(" | "get_fmts_indexes(" | "resolve_unit_keys("
+            );
+            let before = code[..k].last().copied().unwrap_or(' ');
+            let is_item =
+                code[..k].ends_with(&['f', 'n', ' ']) || before.is_alphanumeric() || before == '_';
+            if method && is_item {
+                continue;
+            }
             let via_helper = k >= helper.len() && code[k - helper.len()..k] == helper[..];
             if tok == "decrypt_unit(" && via_helper {
                 continue;
@@ -223,6 +234,10 @@ fn the_structural_guard_skips_comments_and_keeps_its_allow_path() {
     );
     let url = "let u = \"http://x\"; AacsKeyMap::from_ranges_phased(r);\n";
     assert_eq!(hits("src/x.rs", url), [(1, "AacsKeyMap::from_ranges")]);
+    let ufcs = "fn f() { KeySource::get_unit_keys(&s, c); }\n";
+    assert_eq!(hits("src/mux/x.rs", ufcs), [(1, "get_unit_keys(")], "UFCS");
+    let item = "impl K for S { fn get_unit_keys(&self) {} fn my_resolve_unit_keys(&self) {} }\n";
+    assert!(hits("src/x.rs", item).is_empty(), "fn items are not calls");
     let raw = "let s = r#\"x.get_fmts_indexes( // \"#; s.resolve_unit_keys(c);\n";
     assert_eq!(
         hits("src/x.rs", raw).len(),

tests/pass_n_patch_fix.rs

@@ -1,8 +1,7 @@
-//! Regression tests for Pass N (patch) fix — decrypt key inversion bug.
+//! Decrypt-seam checks behind the Pass N (patch) key inversion fix.
 //!
-//! Tests that decrypt_sectors is invoked correctly when opts.decrypt=true.
-//! The 2026-05-03 bug at `libfreemkv/src/disc/mod.rs:1938-1942` inverted
-//! the decrypt key arms, causing patch to pass DecryptKeys::None on encrypted discs.
+//! The patch pass itself now lives in freemkv-engine, so this file cannot guard the arm
+//! selection; it pins the libfreemkv decrypt seam that pass relies on.
 
 use libfreemkv::{aacs, decrypt::DecryptKeys};