M11: PDF/A verify reads an action's type through a reference (6.5.1)

An action whose /S refers to /Named or /NOP is checked like one that
names it directly, so verification reports it and conversion removes it.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Pq7HyDBXygTf7jcqdsjcfn

crates/preflight/src/lib.rs

@@ -789,10 +789,11 @@ fn walk_chain(doc: &Document, a: &Dict, read: &mut usize, seen: &mut std::collec
 }
 
 /// The forbidden kind of the action `d` itself, if it is one: a forbidden type, or a Named
-/// action for anything but the four of [`NAMED_ACTIONS`], its name given directly or by
-/// reference.
+/// action for anything but the four of [`NAMED_ACTIONS`]. The type and the name may each be given
+/// directly or by reference.
 fn action_forbidden(doc: &Document, d: &Dict) -> Option<String> {
-    let s = d.name(b"S")?;
+    let s = doc.resolve(d.get(b"S")?);
+    let s = s.as_name()?;
     if FORBIDDEN_ACTIONS.contains(&s) {
         return Some(String::from_utf8_lossy(s).into_owned());
     }

crates/preflight/src/tests.rs

@@ -502,6 +502,8 @@ fn set_state_no_op_and_named_actions_are_checked() {
                 &outline,
                 "<< /Type /Outlines /First 3 0 R /Last 3 0 R /Count 1 >>",
                 "/NextPage",
+                "/Named",
+                "/NOP",
             ],
             "",
         )
@@ -520,6 +522,10 @@ fn set_state_no_op_and_named_actions_are_checked() {
     }
     // The name given by reference (object 5 is /NextPage).
     assert!(actions("<< /S /Named /N 5 0 R >>").is_empty());
+    // The type given by reference (object 6 is /Named, 7 is /NOP).
+    assert_eq!(actions("<< /S 6 0 R /N /Print >>"), ["A Named Print action isn't allowed"]);
+    assert_eq!(actions("<< /S 7 0 R >>"), ["A NOP action isn't allowed"]);
+    assert!(actions("<< /S 6 0 R /N 5 0 R >>").is_empty());
     // Save as PDF/A removes them.
     for action in ["<< /S /SetState /T [] >>", "<< /S /NOP >>", "<< /S /Named /N /Print >>"] {
         let mut doc = doc_with(action);