M14: Reuse form enumeration during document open (#1011)

Co-authored-by: Brandon Thomas <echelon@gmail.com>

crates/engine/src/lib.rs

@@ -2390,12 +2390,14 @@ impl Session {
         };
         let display = display_bytes(editor.as_ref(), &bytes);
         let renderer = RenderPool::new(display.clone(), render_threads(), config.clone());
-        let mut form = editor.as_ref().map(|e| pdfcraft_forms::fields(&e.cos)).unwrap_or_default();
-        let mut adopted = 0;
-        if let Some(e) = editor.as_ref() {
-            xfa::mark_script_buttons(&e.cos, &mut form);
-            adopted = pdfcraft_forms::adopted_page_fields(&e.cos);
-        }
+        let (form, adopted) = editor
+            .as_ref()
+            .map(|e| {
+                let mut fields = pdfcraft_forms::fields_with_adopted(&e.cos);
+                xfa::mark_script_buttons(&e.cos, &mut fields.items);
+                (fields.items, fields.adopted_page_fields)
+            })
+            .unwrap_or_default();
         // Fields the file lists only as page widgets are adopted leniently; the file says so.
         if adopted > 0
             && let Some(e) = &mut editor

crates/engine/src/tests.rs

@@ -2400,6 +2400,8 @@ fn xfa_scripts_initialize_calculate_validate_toggle_and_add_rows() {
     let bytes = Arc::new(pdfcraft_xfa::fixtures::shell(&pdfcraft_xfa::fixtures::scripted_template()));
     let mut s = Session::new().with_clock(|| 1_700_000_000);
     let id = s.open("scripted.pdf", None, bytes, None).expect("opens");
+    let add_row = s.get(id).unwrap().form.iter().find(|f| f.name == "addRow").expect("the XFA button is in the form snapshot");
+    assert!(matches!(add_row.button.as_ref(), Some(pdfcraft_forms::af::ButtonAction::Script(_))));
     let value = |s: &Session, n: &str| {
         s.get(id).unwrap().form.iter().find(|f| f.name == n).map(|f| f.value.clone()).unwrap_or_else(|| panic!("no field {n}"))
     };
@@ -2828,7 +2830,7 @@ fn adopting_page_only_fields_is_noted_as_a_repair() {
     let doc = s.get(id).unwrap();
     let names: Vec<&str> = doc.form.iter().map(|f| f.name.as_str()).collect();
     assert_eq!(names, ["alpha", "beta"]);
-    assert!(doc.repair_log().iter().any(|l| l.contains("2 fields") && l.contains("page annotations")), "{:?}", doc.repair_log());
+    assert_eq!(doc.repair_log(), vec!["the form's /Fields list omits 2 fields; they were read from the page annotations".to_string()]);
 }
 
 /// A page too large for the renderer at the asked resolution exports at the most it allows (and