From 9ae7788f8df1ca12a05a4d2118a2680e27f148e6 Mon Sep 17 00:00:00 2001
From: Vikram Bhaskaran <vikram.bhaskaran@outlook.com>
Date: Sun, 11 Oct 2026 03:32:01 +1100
Subject: [PATCH] Keep the playhead on the frame shown in the current-time
 field.

Timecode and Frames entries were parsed as absolute counts without the composition Start Timecode or Start Numbering Frames At offset, so committing the displayed text jumped to another frame.
---
 crates/engine/src/commands/time.rs  | 14 +++++++++++++-
 crates/engine/src/tests_timeline.rs | 23 +++++++++++++++++++++++
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/crates/engine/src/commands/time.rs b/crates/engine/src/commands/time.rs
index 9ed41f47..81197602 100644
--- a/crates/engine/src/commands/time.rs
+++ b/crates/engine/src/commands/time.rs
@@ -38,7 +38,19 @@ pub fn parse_display_time(s: &Session, comp: &Comp, text: &str, current: i64) ->
             let start = fr.frame_at(comp.display_start) + st.frame_start;
             effectcraft_time::parse_feet_frames(text, pf, current + start).map(|f| f - start).map_err(|e| e.0)
         }
-        None => effectcraft_time::parse_timecode(text, fr, fr.supports_drop_frame(), current).map_err(|e| e.0),
+        None => {
+            let parsed = effectcraft_time::parse_timecode(text, fr, fr.supports_drop_frame(), current).map_err(|e| e.0)?;
+            let relative = text.trim().starts_with('+') || text.trim().starts_with('-');
+            if relative {
+                Ok(parsed)
+            } else if st.time_display == TimeDisplayStyle::Frames {
+                // Displayed digits are composition frame plus Start Numbering Frames At.
+                Ok(parsed - st.frame_start)
+            } else {
+                // Displayed timecode includes the composition Start Timecode offset.
+                Ok(parsed - fr.frame_at(comp.display_start))
+            }
+        }
     }
 }
 
diff --git a/crates/engine/src/tests_timeline.rs b/crates/engine/src/tests_timeline.rs
index cdfbf8dd..eacf3da3 100644
--- a/crates/engine/src/tests_timeline.rs
+++ b/crates/engine/src/tests_timeline.rs
@@ -375,6 +375,29 @@ fn time_set_snaps_to_the_nearest_frame_and_ae_timecode() {
     assert_eq!(effectcraft_time::format_timecode_ae(75, fr, true), "0;00;02;15");
 }
 
+#[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();
+    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();
+    assert_eq!((r["frame"].as_i64(), r["time"].as_f64()), (Some(0), Some(0.0)));
+
+    s.execute("file.projectSettings", json!({"timeDisplay": "frames"})).unwrap();
+    std::sync::Arc::make_mut(&mut s.project).settings.frame_start = 1;
+    let r = s.execute("time.set", json!({"frame": 12})).unwrap();
+    assert_eq!(r["display"], "00013");
+    let r = s.execute("time.set", json!({"timecode": "00013"})).unwrap();
+    assert_eq!((r["frame"].as_i64(), r["time"].as_f64()), (Some(12), Some(0.4)));
+    let r = s.execute("time.set", json!({"timecode": "+1"})).unwrap();
+    assert_eq!(r["frame"], 13);
+}
+
 #[test]
 fn separate_dimensions_split_and_rejoin() {
     let (mut s, l) = setup();