From 0e50bdfe9e2e04e5e166e8d8bdafa9ea22e747b6 Mon Sep 17 00:00:00 2001
From: NimBold <NimBold@users.noreply.github.com>
Date: Wed, 29 Jul 2026 15:49:53 +0330
Subject: [PATCH] fix(ui): ignore duplicate stale pause events during resume

---
 src/store/downloadStore.test.ts | 13 +++++++++++--
 src/store/downloadStore.ts      | 17 +++++++++--------
 2 files changed, 20 insertions(+), 10 deletions(-)

diff --git a/src/store/downloadStore.test.ts b/src/store/downloadStore.test.ts
index 00a40c9..66192c5 100644
--- a/src/store/downloadStore.test.ts
+++ b/src/store/downloadStore.test.ts
@@ -353,7 +353,7 @@ describe('useDownloadProgressStore', () => {
     release();
   });
 
-  it('ignores a stale paused event during resume and accepts the new active state', async () => {
+  it('ignores duplicate stale paused events during resume and accepts the new active state', async () => {
     const handlers: Record<string, (event: any) => void> = {};
     vi.mocked(ipc.listenEvent).mockImplementation((event, handler) => {
       handlers[event] = handler as (event: any) => void;
@@ -378,6 +378,12 @@ describe('useDownloadProgressStore', () => {
     } });
     expect(useDownloadStore.getState().downloads[0].status).toBe('queued');
 
+    handlers['download-state']({ payload: {
+      id: 'resume-race',
+      status: 'paused'
+    } });
+    expect(useDownloadStore.getState().downloads[0].status).toBe('queued');
+
     handlers['download-state']({ payload: {
       id: 'resume-race',
       status: 'downloading'
@@ -386,7 +392,7 @@ describe('useDownloadProgressStore', () => {
     release();
   });
 
-  it('allows a later genuine pause after consuming the stale resume event', async () => {
+  it('accepts an explicit pause while a resume transition is in flight', async () => {
     const handlers: Record<string, (event: any) => void> = {};
     vi.mocked(ipc.listenEvent).mockImplementation((event, handler) => {
       handlers[event] = handler as (event: any) => void;
@@ -411,6 +417,9 @@ describe('useDownloadProgressStore', () => {
     } });
     expect(useDownloadStore.getState().downloads[0].status).toBe('queued');
 
+    // pauseDownload replaces the resume intent before it asks the backend to
+    // pause, so the next paused event is authoritative.
+    setDownloadControlIntent('resume-pause-race', 'pause');
     handlers['download-state']({ payload: {
       id: 'resume-pause-race',
       status: 'paused'
diff --git a/src/store/downloadStore.ts b/src/store/downloadStore.ts
index 0f5b423..677c205 100644
--- a/src/store/downloadStore.ts
+++ b/src/store/downloadStore.ts
@@ -103,17 +103,18 @@ const startDownloadListeners = async () => {
       const status = payload.status as DownloadStatus;
 
       // resume_download queues the row before the backend can emit its new
-      // active state. A paused event already emitted by the old lifecycle may
-      // arrive in that gap. Do not let it overwrite the queued transition;
-      // otherwise the guard below would reject the legitimate downloading
-      // event and leave the row visibly paused forever.
+      // active state. Paused events already emitted by the old lifecycle may
+      // arrive in that gap, and more than one can be queued before the new
+      // lifecycle reports its state. Do not let any of them overwrite the
+      // queued transition; otherwise a duplicate stale event can leave the
+      // row visibly paused and make dispatch reject it before IPC.
       if (status === 'paused' &&
           current.status === 'queued' &&
           downloadControlIntentFor(payload.id) === 'resume') {
-        // Consume only the stale pause event that caused the resume race.
-        // A later real pause must be allowed through even if the backend has
-        // not emitted a new active state yet.
-        clearDownloadControlIntent(payload.id, 'resume');
+        // Keep the resume intent until an active or terminal event proves
+        // that the new lifecycle has taken over. An explicit pause replaces
+        // this intent in pauseDownload, so a genuine user pause is still
+        // applied while the transition is in flight.
         return;
       }
       if (status === 'downloading' || status === 'processing' ||