Print: a scaled annotation appearance no longer prints larger than its rectangle (#802) (#861)

crates/print/src/lib.rs

@@ -478,7 +478,8 @@ fn appearance_matrix(doc: &Document, form: &Dict, rect: [f64; 4]) -> Option<Matr
         rect[0] - b[0] * (rect[2] - rect[0]) / bw,
         rect[1] - b[1] * (rect[3] - rect[1]) / bh,
     ]);
-    Some(m.then(&a))
+    // The Do that draws the form applies its /Matrix itself, so only the placement goes here.
+    Some(a)
 }
 
 /// A Form XObject holding page `index` as it prints (user space; BBox = crop box).

crates/print/src/tests.rs

@@ -469,3 +469,16 @@ fn printer_option_defaults_and_job_arguments() {
     assert!(args.ends_with("-o fit-to-page=false -o InputSlot=Tray2 -o EFMediaType=Heavy1"), "{args}");
     assert!(spool::printer_options("../../etc/passwd").is_empty(), "not a queue name");
 }
+
+#[test]
+fn a_scaled_appearance_is_not_scaled_twice() {
+    let doc = fixture(1);
+    let nums = |v: [f64; 6]| Object::Array(v.iter().map(|x| Object::Real(*x)).collect());
+    let mut form = Dict::new();
+    form.set(b"BBox".to_vec(), Object::Array([0.0, 0.0, 10.0, 10.0].iter().map(|x| Object::Real(*x)).collect()));
+    form.set(b"Matrix".to_vec(), nums([2.0, 0.0, 0.0, 2.0, 0.0, 0.0]));
+    // The form's own /Matrix doubles it to 20x20 when drawn; the placement only has to map 20x20 onto the 40x40 rect.
+    let m = appearance_matrix(&doc, &form, [10.0, 10.0, 50.0, 50.0]).unwrap();
+    assert!(close(m.0[0], 2.0) && close(m.0[3], 2.0), "{:?}", m.0);
+    assert!(close(m.0[4], 10.0) && close(m.0[5], 10.0), "{:?}", m.0);
+}