fix(mpv): move a pending replay pause when sub-delay changes

src/core/services/mpv-protocol.test.ts

@@ -399,17 +399,25 @@ test('dispatchMpvProtocolMessage pauses on sub-end when pendingPauseAtSubEnd is
 
 test('dispatchMpvProtocolMessage pauses at the sub-delay retimed sub-end', async () => {
   let pauseAtTime: number | null = null;
+  let subDelay = 1.5;
   const { deps } = createDeps({
     getPendingPauseAtSubEnd: () => true,
-    getCurrentSubDelay: () => 1.5,
+    getCurrentSubDelay: () => subDelay,
+    setCurrentSubDelay: (next) => {
+      subDelay = next;
+    },
+    getPauseAtTime: () => pauseAtTime,
     setPauseAtTime: (next) => {
       pauseAtTime = next;
     },
   });
 
   await dispatchMpvProtocolMessage({ event: 'property-change', name: 'sub-end', data: 42 }, deps);
-
   assert.equal(pauseAtTime, 43.5);
+
+  // Retiming before the replay reaches its end moves the pause with the line.
+  await dispatchMpvProtocolMessage({ event: 'property-change', name: 'sub-delay', data: 2 }, deps);
+  assert.equal(pauseAtTime, 44);
 });
 
 test('dispatchMpvProtocolMessage updates current time before emitting time-pos change', async () => {

src/core/services/mpv-protocol.ts

@@ -277,8 +277,15 @@ export async function dispatchMpvProtocolMessage(
         end: deps.getCurrentSubEnd(),
       });
     } else if (msg.name === 'sub-delay') {
-      const delay = typeof msg.data === 'number' ? msg.data : Number(msg.data);
+      const parsed = typeof msg.data === 'number' ? msg.data : Number(msg.data);
-      deps.setCurrentSubDelay(Number.isFinite(delay) ? delay : 0);
+      const delay = Number.isFinite(parsed) ? parsed : 0;
+      // A scheduled replay pause sits at the line's end on the video clock; retiming
+      // mid-replay moves that end, so the pause moves with it.
+      const pauseAtTime = deps.getPauseAtTime();
+      if (pauseAtTime !== null) {
+        deps.setPauseAtTime(pauseAtTime + delay - deps.getCurrentSubDelay());
+      }
+      deps.setCurrentSubDelay(delay);
     } else if (msg.name === 'secondary-sub-text') {
       const nextSubText = (msg.data as string) || '';
       deps.setCurrentSecondarySubText(nextSubText);