Time: in Frames style a typed number is a frame count (#610 follow-up)

parse_timecode reads bare digits as timecode pairs, so 00100 went to
frame 30 (1 s) instead of frame 100.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Claude-Session: https://claude.ai/code/session_01QiAJeFttZp83Fh7YuzAR5f

crates/engine/src/commands/time.rs

@@ -43,12 +43,17 @@ pub fn parse_display_time(s: &Session, comp: &Comp, text: &str, current: i64) ->
             let relative = text.trim().starts_with('+') || text.trim().starts_with('-');
             if relative {
                 Ok(parsed)
+            } else if st.time_display == TimeDisplayStyle::Frames
+                && let Ok(frame) = text.trim().parse::<i64>()
+            {
+                // Displayed digits are a plain frame count (00100 is frame 100, not 1 s) plus
+                // Start Numbering Frames At.
+                Ok(frame.saturating_sub(st.frame_start))
             } else if st.time_display == TimeDisplayStyle::Frames {
-                // Displayed digits are composition frame plus Start Numbering Frames At.
-                Ok(parsed - st.frame_start)
+                Ok(parsed.saturating_sub(st.frame_start))
             } else {
                 // Displayed timecode includes the composition Start Timecode offset.
-                Ok(parsed - fr.frame_at(comp.display_start))
+                Ok(parsed.saturating_sub(fr.frame_at(comp.display_start)))
             }
         }
     }

crates/engine/src/tests_timeline.rs

@@ -413,11 +413,7 @@ fn time_set_snaps_to_the_nearest_frame_and_ae_timecode() {
 #[test]
 fn time_set_keeps_the_frame_shown_in_the_current_time_field() {
     let mut s = Session::default();
-    s.execute(
-        "comp.new",
-        json!({"name": "Example", "width": 64, "height": 64, "frameRate": 30, "duration": 0.6, "startTimecode": "0:00:00:05"}),
-    )
-    .unwrap();
+    s.execute("comp.new", json!({"name": "Example", "width": 64, "height": 64, "frameRate": 30, "duration": 0.6, "startTimecode": "0:00:00:05"})).unwrap();
     let r = s.execute("time.set", json!({"frame": 0})).unwrap();
     assert_eq!(r["display"], "0:00:00:05");
     let r = s.execute("time.set", json!({"timecode": "0:00:00:05"})).unwrap();
@@ -433,6 +429,17 @@ fn time_set_keeps_the_frame_shown_in_the_current_time_field() {
     assert_eq!(r["frame"], 13);
 }
 
+/// Frames display style: typed digits are a frame count, so 00100 is frame 100, not 1 s (#530).
+#[test]
+fn time_set_reads_frames_style_digits_as_a_frame_count() {
+    let mut s = Session::default();
+    s.execute("comp.new", json!({"name": "Long", "width": 64, "height": 64, "frameRate": 30, "duration": 10})).unwrap();
+    s.execute("file.projectSettings", json!({"timeDisplay": "frames"})).unwrap();
+    let r = s.execute("time.set", json!({"timecode": "00100"})).unwrap();
+    assert_eq!(r["frame"], 100);
+    assert_eq!(r["display"], "00100");
+}
+
 #[test]
 fn separate_dimensions_split_and_rejoin() {
     let (mut s, l) = setup();