PPTX: animation rewind survives save and reopen (#77)

crates/pptx/src/read/timing.rs

@@ -137,6 +137,8 @@ pub fn animations(imp: &mut Imp, part: &Part, ctx: &IdCtx, timing: &El, _shapes:
             preset_id: Some(preset),
             preset_subtype: Some(sub),
             auto_reverse: c.bool("autoRev").unwrap_or(false),
+            // PowerPoint's "Rewind when done playing" is `fill="remove"` on the effect node.
+            rewind: c.attr("fill") == Some("remove"),
             smooth_start: c.f64("accel").map(|v| v / 100_000.0).unwrap_or(0.0),
             smooth_end: c.f64("decel").map(|v| v / 100_000.0).unwrap_or(0.0),
             ..Default::default()

crates/pptx/src/write/timing.rs

@@ -445,7 +445,7 @@ fn effect_par(w: &mut W, x: &mut Exp, ids: &mut Ids, e: &Eff, first_in_click: bo
             .o("accel", accel)
             .o("decel", decel)
             .t("autoRev", a.auto_reverse)
-            .a("fill", "hold")
+            .a("fill", if a.rewind { "remove" } else { "hold" })
             .a("grpId", e.grp)
             .a("nodeType", node),
     );

crates/pptx/tests/roundtrip.rs

@@ -633,6 +633,23 @@ fn every_animation_effect_survives() {
     }
 }
 
+#[test]
+fn animation_rewind_survives() {
+    let mut p = defaults::new_presentation(None);
+    let mut s = p.slides[0].as_ref().clone();
+    let sh = shape(&mut p, "Target", 100.0, 100.0, 100.0, 100.0);
+    let id = sh.id;
+    s.shapes.push(sh);
+    s.animations.push(Animation { shape: id, rewind: true, ..Default::default() });
+    s.animations.push(Animation { shape: id, effect: "fly".into(), option: "l".into(), start: AnimStart::WithPrevious, ..Default::default() });
+    p.slides[0] = Arc::new(s);
+    let q = round(&p);
+    let b = &q.slides[0].animations;
+    assert_eq!(b.len(), 2);
+    assert!(b[0].rewind);
+    assert!(!b[1].rewind);
+}
+
 /// Writes bisection variants of the rich deck to `DECKCRAFT_PPTX_BISECT` (manual checks).
 #[test]
 fn bisect_variants() {