fix(properties): harden progress and torrent diagnostics

src-tauri/src/lib.rs

@@ -8494,6 +8494,8 @@ async fn verify_torrent_data(
     let metadata = crate::torrent::parse_torrent_bytes(&bytes)?;
     crate::torrent::validate_info_hash(item.torrent_info_hash.as_deref(), &metadata.info_hash)?;
     let restore_status = item.status.as_str().to_string();
+    let restore_status_value = item.status;
+    let restore_has_been_dispatched = item.has_been_dispatched;
     let destination = verification_destination(&app_handle, &item)?;
     if matches!(item.status, crate::ipc::DownloadStatus::Paused) {
         detach_download_for_reconfigure_locked(
@@ -8508,6 +8510,11 @@ async fn verify_torrent_data(
     {
         return Err("Torrent lifecycle changed; pause it before verifying its data".to_string());
     }
+    // Allocate the internally-created generation after detaching any retained
+    // paused lifecycle, so the value includes every cancellation watermark
+    // observed during that transition. Reservation still remains the atomic
+    // acceptance point immediately before ownership registration.
+    let verification_generation = state.queue_manager.next_enqueue_generation(&id).await?;
     let enqueue_item = queue::EnqueueItem {
         id: item.id.clone(),
         queue_id: item
@@ -8559,7 +8566,7 @@ async fn verify_torrent_data(
         torrent_file_allocation: item.torrent_file_allocation.clone(),
         torrent_verify_only: Some(true),
         torrent_verify_restore_status: Some(restore_status.clone()),
-        lifecycle_generation: None,
+        lifecycle_generation: Some(verification_generation.to_string()),
     };
 
     {
@@ -8589,9 +8596,10 @@ async fn verify_torrent_data(
         enqueue_download_locked(&app_handle, state.inner(), enqueue_item, &control_guard).await
     {
         // Roll back only this verification marker, and only while the row is
-        // still the queued verification lifecycle. Never restore the stale
-        // full array captured before enqueue: frontend persistence or another
-        // command may have changed unrelated rows in the meantime.
+        // still this verification lifecycle (queued or already restored by a
+        // renderer snapshot). Never restore the stale full array captured
+        // before enqueue: frontend persistence or another command may have
+        // changed unrelated rows in the meantime.
         let rollback_result = (|| {
             let mut connection = database.lock()?;
             crate::db::mutate_download(
@@ -8599,18 +8607,20 @@ async fn verify_torrent_data(
                 &id,
                 database.is_portable(),
                 |object| {
-                    let is_verification_marker = object
-                        .get("status")
-                        .and_then(serde_json::Value::as_str)
-                        == Some("queued")
-                        && object
-                            .get("torrentVerifyOnly")
-                            .and_then(serde_json::Value::as_bool)
-                            == Some(true)
+                    let has_verification_marker = object
+                        .get("torrentVerifyOnly")
+                        .and_then(serde_json::Value::as_bool)
+                        == Some(true)
                         && object
                             .get("torrentVerifyRestoreStatus")
                             .and_then(serde_json::Value::as_str)
                             == Some(restore_status.as_str());
+                    let current_status = object
+                        .get("status")
+                        .and_then(serde_json::Value::as_str);
+                    let is_verification_marker = has_verification_marker
+                        && (current_status == Some("queued")
+                            || current_status == Some(restore_status.as_str()));
                     // The native marker is an additional persistence fence,
                     // not a prerequisite for rollback. A renderer snapshot
                     // may have already acknowledged and removed that native
@@ -8621,18 +8631,39 @@ async fn verify_torrent_data(
                             "status".to_string(),
                             serde_json::json!(restore_status),
                         );
+                        match restore_has_been_dispatched {
+                            Some(value) => {
+                                object.insert(
+                                    "hasBeenDispatched".to_string(),
+                                    serde_json::json!(value),
+                                );
+                            }
+                            None => {
+                                object.remove("hasBeenDispatched");
+                            }
+                        }
                         object.remove("torrentVerifyOnly");
                         object.remove("torrentVerifyRestoreStatus");
                         object.remove("torrentVerifyNative");
                     }
-                    Ok(())
+                    Ok(is_verification_marker)
                 },
             )
         })();
-        if let Err(rollback_error) = rollback_result {
-            return Err(format!(
-                "{error}; failed to roll back Torrent verification state: {rollback_error}"
-            ));
+        let rollback_applied = match rollback_result {
+            Ok(applied) => applied,
+            Err(rollback_error) => {
+                return Err(format!(
+                    "{error}; failed to roll back Torrent verification state: {rollback_error}"
+                ));
+            }
+        };
+        if rollback_applied {
+            use tauri::Emitter;
+            let _ = app_handle.emit(
+                "download-state",
+                crate::ipc::DownloadStateEvent::new(&id, restore_status_value),
+            );
         }
         return Err(error.to_string());
     }

src-tauri/src/queue.rs

@@ -1615,6 +1615,21 @@ impl<R: tauri::Runtime> QueueManager<R> {
             .or_insert(generation);
     }
 
+    /// Return a generation newer than every observed or cancelled enqueue for
+    /// an internally-created lifecycle. The caller still passes this value to
+    /// `reserve_enqueue_generation`, which performs the atomic ownership and
+    /// cancellation checks before the enqueue is committed.
+    pub async fn next_enqueue_generation(&self, id: &str) -> Result<u64, String> {
+        let cancellations = self.enqueue_cancellations.lock().await;
+        let generations = self.enqueue_generations.lock().await;
+        let previous_generation = generations.get(id).copied().unwrap_or_default();
+        let cancelled_generation = cancellations.get(id).copied().unwrap_or_default();
+        previous_generation
+            .max(cancelled_generation)
+            .checked_add(1)
+            .ok_or_else(|| "Download lifecycle generation exhausted".to_string())
+    }
+
     /// Atomically reserve an ID after rejecting cancelled or replayed generations.
     /// The returned watermark must be passed to `rollback_enqueue_reservation`
     /// if ownership registration fails before the task is committed.
@@ -8184,6 +8199,27 @@ mod tests {
         assert!(item.into_task().payload.torrent_remove_unselected_file);
     }
 
+    #[tokio::test]
+    async fn internally_created_enqueue_advances_past_cancelled_generation() {
+        let app = tauri::test::mock_builder()
+            .build(tauri::test::mock_context(tauri::test::noop_assets()))
+            .expect("mock app");
+        let manager = QueueManager::test_new(app.handle().clone(), 1, Arc::new(TestSpawner));
+
+        manager.cancel_enqueue_generation("torrent", 4).await;
+        let generation = manager
+            .next_enqueue_generation("torrent")
+            .await
+            .expect("a fresh generation should be available");
+
+        assert_eq!(generation, 5);
+        manager
+            .reserve_enqueue_generation("torrent", generation)
+            .await
+            .expect("the fresh generation should not be rejected as stale");
+        assert_eq!(manager.registered_lifecycle_generation("torrent").await, Some(5));
+    }
+
     #[test]
     fn torrent_options_reject_invalid_seed_values() {
         let mut options = serde_json::Map::new();

src/components/DownloadItem.tsx

@@ -15,7 +15,8 @@ import {
   downloadProgressColorClass,
   formatTorrentDuration,
   formatDownloadTotal,
-  resolveDownloadSizeDisplay
+  resolveDownloadSizeDisplay,
+  resolveDownloadFraction
 } from '../utils/downloadProgress';
 import {
   COLUMN_ALIGNMENT_JUSTIFY,
@@ -180,11 +181,24 @@ export const DownloadItem = React.memo<DownloadItemProps>(({
     };
   }, [isActionVisible, updateActionPosition]);
 
-  const displayFraction = download.status === 'moving'
-    ? moveProgress ?? download.fraction ?? 0
+  const progressFraction = download.status === 'moving'
+    ? moveProgress ?? download.fraction
     : download.status === 'downloading' || download.status === 'verifying' || download.status === 'seeding'
-    ? liveProgress?.fraction ?? download.fraction ?? 0
-    : download.fraction ?? 0;
+    ? liveProgress?.fraction ?? download.fraction
+    : download.fraction;
+  const displayFraction = download.status === 'moving' && moveProgress !== undefined
+    ? Math.max(0, Math.min(1, moveProgress))
+    : download.status === 'moving'
+    ? resolveDownloadFraction({ fraction: progressFraction, status: download.status })
+    : resolveDownloadFraction({
+      fraction: progressFraction,
+      downloadedBytes: liveProgress?.downloaded_bytes ?? download.downloadedBytes,
+      totalBytes: liveProgress?.total_bytes ?? download.totalBytes,
+      totalIsEstimate: liveProgress?.total_is_estimate ?? download.totalIsEstimate,
+      isMedia: download.isMedia,
+      size: download.size,
+      status: download.status,
+    });
   const displayPercent = `${(displayFraction * 100).toFixed(0)}%`;
   const displaySpeed = download.status === 'seeding'
     ? liveProgress?.upload_speed ?? '-'

src/components/PropertiesWindowApp.tsx

@@ -36,12 +36,14 @@ import {
   type PropertiesSnapshot,
   type PropertiesSnapshotEvent,
 } from '../propertiesBridge';
-import { formatDownloadBytes, formatTorrentRatio } from '../utils/downloadProgress';
+import { formatDownloadBytes, formatTorrentRatio, resolveDownloadFraction } from '../utils/downloadProgress';
 import { changeAppLocale } from '../i18n';
 import { synchronizeDocumentAppearance } from '../utils/documentAppearance';
 import { getWindowControlRailWidth } from '../utils/windowControlStyle';
 import { getPropertiesFooterActions } from '../utils/propertiesFooter';
 import {
+  formatPropertiesAvailability,
+  formatPropertiesDiagnosticCount,
   getPropertiesAvailabilityDiagnosticState,
   getPropertiesPeerDiagnosticState,
 } from '../utils/propertiesDiagnostics';
@@ -1067,7 +1069,15 @@ export const PropertiesWindowApp = () => {
     );
   }
 
-  const progress = Math.max(0, Math.min(1, snapshot.fraction ?? 0));
+  const progress = resolveDownloadFraction({
+    fraction: snapshot.fraction,
+    downloadedBytes: snapshot.downloadedBytes,
+    totalBytes: snapshot.totalBytes,
+    totalIsEstimate: snapshot.totalIsEstimate,
+    isMedia: snapshot.isMedia,
+    size: snapshot.size,
+    status: snapshot.status,
+  });
   const lifecycleAction = getPropertiesLifecycleAction(snapshot.status);
   const editingEnabled = pendingAction === null && isEditableStatus(snapshot.status);
   const footerActions = getPropertiesFooterActions({
@@ -1329,7 +1339,10 @@ export const PropertiesWindowApp = () => {
                 <span className="properties-diagnostic-label">{t($ => $.properties.torrentPeerDiagnostics)}</span>
                 <p className="properties-diagnostic-value" data-value-state={peerDiagnosticState} role="status">
                   {peers
-                    ? t($ => $.properties.torrentPeerCount, { total: peers.totalPeers, seeders: peers.totalSeeders })
+                    ? t($ => $.properties.torrentPeerCount, {
+                      total: formatPropertiesDiagnosticCount(peers.totalPeers, snapshot.appearance.locale),
+                      seeders: formatPropertiesDiagnosticCount(peers.totalSeeders, snapshot.appearance.locale),
+                    })
                     : diagnosticsLoading
                       ? t($ => $.properties.torrentPeerDiagnosticsLoading)
                       : t($ => $.properties.torrentPeerDiagnosticsUnavailable)}
@@ -1341,7 +1354,15 @@ export const PropertiesWindowApp = () => {
             {peerDiagnosticPhase === 'stale' && <p className="properties-diagnostic-detail">{t($ => $.properties.torrentPeerDiagnosticsStale)}</p>}
             {peers?.truncated && <p className="properties-diagnostic-detail">{t($ => $.properties.torrentPeerShowing, { shown: peers.peers.length, total: peers.totalPeers })}</p>}
           </div>
-          <div className="properties-diagnostic-card" data-diagnostic-phase={availabilityDiagnosticPhase}><span className="properties-diagnostic-label">{t($ => $.properties.torrentAvailability)}</span><p className="properties-diagnostic-value" data-value-state={availabilityDiagnosticState}>{availability ? `${availability.availability} · ${availability.pieceCount} ${t($ => $.properties.torrentDetailsPieces)}` : '—'}</p>{availabilityDiagnosticPhase === 'stale' && <p className="properties-diagnostic-detail">{t($ => $.properties.torrentPeerDiagnosticsStale)}</p>}</div>
+          <div className="properties-diagnostic-card" data-diagnostic-phase={availabilityDiagnosticPhase}>
+            <div className="min-w-0">
+              <span className="properties-diagnostic-label">{t($ => $.properties.torrentAvailability)}</span>
+              <p className="properties-diagnostic-value" data-value-state={availabilityDiagnosticState}>
+                {availability ? `${formatPropertiesAvailability(availability.availability, snapshot.appearance.locale)} — ${formatPropertiesDiagnosticCount(availability.pieceCount, snapshot.appearance.locale)} ${t($ => $.properties.torrentDetailsPieces)}` : '—'}
+              </p>
+            </div>
+            {availabilityDiagnosticPhase === 'stale' && <p className="properties-diagnostic-detail">{t($ => $.properties.torrentPeerDiagnosticsStale)}</p>}
+          </div>
           <div className="overflow-auto rounded-lg border border-border-modal"><table className="w-full min-w-[640px] text-xs" dir="ltr"><thead className="bg-sidebar-bg text-left text-text-muted"><tr><th className="p-2">{t($ => $.properties.torrentPeerAddress)}</th><th className="p-2">{t($ => $.properties.torrentPeerDownload)}</th><th className="p-2">{t($ => $.properties.torrentPeerUpload)}</th><th className="p-2">{t($ => $.properties.torrentPeerSeeder)}</th><th className="p-2">{t($ => $.properties.torrentPeerChoking)}</th></tr></thead><tbody>{peers?.peers.map((peer, index) => <tr key={`${peer.ip ?? 'peer'}-${peer.port ?? 'unknown'}-${index}`} className="border-t border-border-modal/60"><td className="p-2 font-mono">{peer.ip ? `${peer.ip.includes(':') ? `[${peer.ip}]` : peer.ip}${peer.port == null ? '' : `:${peer.port}`}` : '—'}</td><td className="properties-data-value p-2">{formatDownloadBytes(peer.downloadSpeed)}/s</td><td className="properties-data-value p-2">{formatDownloadBytes(peer.uploadSpeed)}/s</td><td className="p-2">{peer.seeder ? '✓' : '—'}</td><td className="p-2">{peer.peerChoking ? '✓' : '—'}</td></tr>)}</tbody></table></div>
           {diagnosticError && <p className="text-xs text-red-400" role="alert">{diagnosticError}</p>}
         </div>}

src/i18n/catalogs/en.ts

@@ -340,7 +340,7 @@ const common = {
     torrentWebSeedsAdd: 'Add web seed',
     torrentWebSeedsRemove: 'Remove web seed',
     torrentWebSeedsInvalid: 'Each web-seed row needs a valid Torrent file and an HTTP(S) base URI without credentials or fragments.',
-    torrentPeerCount: '{{total}} peers · {{seeders}} seeders',
+    torrentPeerCount: '{{total}} peers — {{seeders}} seeders',
     torrentPeerDownload: 'Download',
     torrentPeerUpload: 'Upload',
     torrentPeerSeeder: 'Seeder',

src/i18n/catalogs/fa.ts

@@ -340,7 +340,7 @@ const fa = {
     torrentWebSeedsAdd: 'افزودن وب‌سید',
     torrentWebSeedsRemove: 'حذف وب‌سید',
     torrentWebSeedsInvalid: 'هر ردیف وب‌سید باید فایل معتبر تورنت و نشانی پایهٔ HTTP(S) بدون اطلاعات ورود یا fragment داشته باشد.',
-    torrentPeerCount: '{{total}} همتا · {{seeders}} سید',
+    torrentPeerCount: '{{total}} همتا — {{seeders}} سید',
     torrentPeerDownload: 'دریافت',
     torrentPeerUpload: 'آپلود',
     torrentPeerSeeder: 'سید',

src/i18n/catalogs/he.ts

@@ -340,7 +340,7 @@ const he = {
     torrentWebSeedsAdd: 'הוסף זריעת Web',
     torrentWebSeedsRemove: 'הסר זריעת Web',
     torrentWebSeedsInvalid: 'כל שורת זריעת Web צריכה קובץ טורנט תקין וכתובת בסיס HTTP(S) ללא פרטי התחברות או fragment.',
-    torrentPeerCount: '{{total}} עמיתים · {{seeders}} משתפים',
+    torrentPeerCount: '{{total}} עמיתים — {{seeders}} משתפים',
     torrentPeerDownload: 'הורדה',
     torrentPeerUpload: 'העלאה',
     torrentPeerSeeder: 'משתף',

src/i18n/catalogs/ru.ts

@@ -340,7 +340,7 @@ const ru = {
     torrentWebSeedsAdd: 'Добавить веб-сид',
     torrentWebSeedsRemove: 'Удалить веб-сид',
     torrentWebSeedsInvalid: 'В каждой строке веб-сида нужны допустимый файл торрента и базовый HTTP(S)-адрес без учётных данных или фрагмента.',
-    torrentPeerCount: '{{total}} пиров · {{seeders}} сидеров',
+    torrentPeerCount: '{{total}} пиров — {{seeders}} сидеров',
     torrentPeerDownload: 'Загрузка',
     torrentPeerUpload: 'Отдача',
     torrentPeerSeeder: 'Сидер',

src/i18n/catalogs/uk.ts

@@ -340,7 +340,7 @@ const uk = {
     torrentWebSeedsAdd: 'Додати вебсід',
     torrentWebSeedsRemove: 'Видалити вебсід',
     torrentWebSeedsInvalid: 'Кожен рядок вебсіду має містити дійсний файл торента й базову HTTP(S)-адресу без облікових даних або фрагмента.',
-    torrentPeerCount: '{{total}} пірів · {{seeders}} сідів',
+    torrentPeerCount: '{{total}} пірів — {{seeders}} сідів',
     torrentPeerDownload: 'Завантаження',
     torrentPeerUpload: 'Віддача',
     torrentPeerSeeder: 'Сідер',

src/i18n/catalogs/zh-CN.ts

@@ -340,7 +340,7 @@ const zhCN = {
     torrentWebSeedsAdd: '添加 Web 做种',
     torrentWebSeedsRemove: '移除 Web 做种',
     torrentWebSeedsInvalid: '每行 Web 做种都需要有效的 Torrent 文件和不含凭据或片段的 HTTP(S) 基础地址。',
-    torrentPeerCount: '{{total}} 个节点 · {{seeders}} 个做种节点',
+    torrentPeerCount: '{{total}} 个节点 — {{seeders}} 个做种节点',
     torrentPeerDownload: '下载',
     torrentPeerUpload: '上传',
     torrentPeerSeeder: '做种',

src/index.css

@@ -983,7 +983,7 @@ html[data-list-density="relaxed"] {
 
   .properties-diagnostic-card {
     min-width: 0;
-    padding: 12px;
+    padding: 10px 12px;
     border: 1px solid var(--properties-card-border);
     border-radius: 10px;
     background: var(--properties-card-surface);
@@ -1014,38 +1014,38 @@ html[data-list-density="relaxed"] {
     min-width: 0;
     align-items: flex-start;
     justify-content: space-between;
-    gap: 12px;
+    gap: 8px;
   }
 
   .properties-diagnostic-label {
     color: hsl(var(--text-muted));
-    font-size: 11px;
-    font-weight: 700;
-    letter-spacing: 0.025em;
+    font-size: 10px;
+    font-weight: 650;
+    letter-spacing: 0.04em;
     text-transform: uppercase;
   }
 
   .properties-diagnostic-value {
     margin-top: 6px;
     color: var(--properties-live-value);
-    font-size: 15px;
+    font-size: 13px;
     font-variant-numeric: tabular-nums;
-    font-weight: 750;
+    font-weight: 650;
     line-height: 1.25;
   }
 
   .properties-diagnostic-hint {
     max-width: 60ch;
-    margin-top: 8px;
+    margin-top: 6px;
     color: hsl(var(--text-secondary));
-    font-size: 11px;
-    line-height: 1.45;
+    font-size: 10px;
+    line-height: 1.35;
   }
 
   .properties-diagnostic-detail {
-    margin-top: 8px;
+    margin-top: 6px;
     color: hsl(var(--text-muted));
-    font-size: 11px;
+    font-size: 10px;
     font-variant-numeric: tabular-nums;
   }
 

src/propertiesBridge.test.ts

@@ -334,6 +334,8 @@ describe('Properties window bridge', () => {
   it('recognizes expected diagnostics gaps without hiding real RPC failures', () => {
     expect(isExpectedPropertiesDiagnosticUnavailable(new Error('live Torrent file progress is unavailable'))).toBe(true);
     expect(isExpectedPropertiesDiagnosticUnavailable(new Error('active Torrent transfer has no current gid mapping'))).toBe(true);
+    expect(isExpectedPropertiesDiagnosticUnavailable(new Error('active Torrent transfer has a stale control epoch'))).toBe(true);
+    expect(isExpectedPropertiesDiagnosticUnavailable(new Error('active Torrent has a stale control epoch'))).toBe(true);
     expect(isExpectedPropertiesDiagnosticUnavailable(new Error('Torrent lifecycle changed while reading peer diagnostics'))).toBe(true);
     expect(isExpectedPropertiesDiagnosticUnavailable(new Error('aria2.getPeers failed: unavailable response'))).toBe(false);
     expect(isExpectedPropertiesDiagnosticUnavailable(new Error('aria2.getFiles failed: connection refused'))).toBe(false);

src/utils/downloadProgress.test.ts

@@ -1,5 +1,10 @@
 import { describe, expect, it } from 'vitest';
-import { formatDownloadBytes, formatDownloadTotal, resolveDownloadSizeDisplay } from './downloadProgress';
+import {
+  formatDownloadBytes,
+  formatDownloadTotal,
+  resolveDownloadFraction,
+  resolveDownloadSizeDisplay,
+} from './downloadProgress';
 
 describe('download progress size display', () => {
   it('formats byte counts using the binary units used by the download engines', () => {
@@ -44,3 +49,62 @@ describe('download progress size display', () => {
     expect(formatDownloadTotal(display)).toBe('2.40 GB');
   });
 });
+
+describe('resolveDownloadFraction', () => {
+  it('reconstructs paused progress from exact persisted byte counters', () => {
+    expect(resolveDownloadFraction({
+      status: 'paused',
+      downloadedBytes: 662 * 1024 ** 2,
+      totalBytes: 2.94 * 1024 ** 3,
+    })).toBeCloseTo(0.2199, 3);
+  });
+
+  it('uses a live fraction when it is available', () => {
+    expect(resolveDownloadFraction({
+      fraction: 0.37,
+      downloadedBytes: 90,
+      totalBytes: 100,
+      status: 'downloading',
+    })).toBe(0.37);
+  });
+
+  it('does not infer progress from an estimated media total', () => {
+    expect(resolveDownloadFraction({
+      fraction: 0,
+      downloadedBytes: 900,
+      totalBytes: 1000,
+      totalIsEstimate: true,
+      isMedia: true,
+      size: '~1000 B',
+      status: 'paused',
+    })).toBe(0);
+  });
+
+  it('keeps zero at the start and does not divide by an unknown total', () => {
+    expect(resolveDownloadFraction({
+      downloadedBytes: 0,
+      totalBytes: 0,
+      status: 'paused',
+    })).toBe(0);
+    expect(resolveDownloadFraction({
+      downloadedBytes: 500,
+      status: 'paused',
+    })).toBe(0);
+  });
+
+  it('shows completed downloads as complete even when volatile fraction was removed', () => {
+    expect(resolveDownloadFraction({
+      status: 'completed',
+      downloadedBytes: 0,
+      totalBytes: 100,
+    })).toBe(1);
+  });
+
+  it('clamps inconsistent exact byte counters', () => {
+    expect(resolveDownloadFraction({
+      downloadedBytes: 150,
+      totalBytes: 100,
+      status: 'paused',
+    })).toBe(1);
+  });
+});

src/utils/downloadProgress.ts

@@ -6,11 +6,62 @@ export interface DownloadSizeDisplay {
   fallback: string;
 }
 
+export type DownloadFractionInput = {
+  fraction?: number | null;
+  downloadedBytes?: number | null;
+  totalBytes?: number | null;
+  totalIsEstimate?: boolean | null;
+  isMedia?: boolean | null;
+  size?: string | null;
+  status?: string | null;
+};
+
 const BYTE_UNITS = ['B', 'KB', 'MB', 'GB', 'TB'] as const;
 
 const isUsableByteCount = (value: number | null | undefined): value is number =>
   typeof value === 'number' && Number.isFinite(value) && value >= 0;
 
+const isUsableFraction = (value: number | null | undefined): value is number =>
+  typeof value === 'number' && Number.isFinite(value) && value >= 0 && value <= 1;
+
+const clampFraction = (value: number): number => Math.max(0, Math.min(1, value));
+
+/**
+ * Resolves the fraction shown by progress bars when a live fraction is not
+ * available. Volatile fractions are intentionally omitted from persisted
+ * downloads, but paused rows retain exact byte counters so their progress can
+ * still be reconstructed after restart. Estimated media totals are excluded:
+ * they describe a provisional denominator and must not become a false visual
+ * claim about completion.
+ */
+export const resolveDownloadFraction = ({
+  fraction,
+  downloadedBytes,
+  totalBytes,
+  totalIsEstimate = false,
+  isMedia = false,
+  size,
+  status
+}: DownloadFractionInput): number => {
+  if (status === 'completed') return 1;
+
+  const storedFraction = isUsableFraction(fraction) ? fraction : undefined;
+  if (storedFraction !== undefined && storedFraction > 0) return storedFraction;
+
+  const hasEstimatedTotal = totalIsEstimate === true ||
+    (isMedia === true && size?.trim().startsWith('~') === true);
+  if (
+    !hasEstimatedTotal &&
+    isUsableByteCount(downloadedBytes) &&
+    isUsableByteCount(totalBytes) &&
+    totalBytes > 0
+  ) {
+    return clampFraction(downloadedBytes / totalBytes);
+  }
+
+  return storedFraction ?? 0;
+};
+
 const byteUnitIndex = (bytes: number): number => {
   let value = bytes;
   let unitIndex = 0;

src/utils/propertiesDiagnostics.test.ts

@@ -1,5 +1,7 @@
 import { describe, expect, it } from 'vitest';
 import {
+  formatPropertiesAvailability,
+  formatPropertiesDiagnosticCount,
   getPropertiesAvailabilityDiagnosticState,
   getPropertiesPeerDiagnosticState,
 } from './propertiesDiagnostics';
@@ -12,6 +14,20 @@ const emptyPeerDiagnostics = {
 };
 
 describe('Properties peer diagnostics presentation state', () => {
+  it('formats swarm availability without exposing floating-point noise', () => {
+    expect(formatPropertiesAvailability(6.05186170212766, 'en-US')).toBe('6.05');
+    expect(formatPropertiesAvailability(1.5, 'en-US')).toBe('1.5');
+    expect(formatPropertiesAvailability(1.5, '')).toBe('1.5');
+    expect(formatPropertiesAvailability(Number.NaN, 'en-US')).toBe('—');
+  });
+
+  it('formats diagnostic counts with the same locale as availability', () => {
+    expect(formatPropertiesDiagnosticCount(1234, 'en-US')).toBe('1,234');
+    expect(formatPropertiesDiagnosticCount(1234, 'fa')).toBe(new Intl.NumberFormat('fa').format(1234));
+    expect(formatPropertiesDiagnosticCount(-1, 'en-US')).toBe('—');
+    expect(formatPropertiesDiagnosticCount(Number.MAX_SAFE_INTEGER + 1, 'en-US')).toBe('—');
+  });
+
   it('keeps a genuine empty response live instead of treating it as unavailable', () => {
     expect(getPropertiesPeerDiagnosticState(emptyPeerDiagnostics, false, 'idle')).toBe('live');
   });

src/utils/propertiesDiagnostics.ts

@@ -1,9 +1,20 @@
 import type { TorrentPeerDiagnostics } from '../bindings/TorrentPeerDiagnostics';
 import type { TorrentAvailabilitySnapshot } from '../bindings/TorrentAvailabilitySnapshot';
+import { resolveAppLocale } from '../i18n/locales';
 import type { PropertiesDiagnosticPhase } from '../propertiesBridge';
 
 export type PropertiesDiagnosticValueState = 'live' | 'loading' | 'stale' | 'error' | 'unavailable';
 
+export const formatPropertiesDiagnosticCount = (value: number, locale: string): string => {
+  if (!Number.isSafeInteger(value) || value < 0) return '—';
+  return new Intl.NumberFormat(resolveAppLocale(locale)).format(value);
+};
+
+export const formatPropertiesAvailability = (availability: number, locale: string): string => {
+  if (!Number.isFinite(availability) || availability < 0) return '—';
+  return new Intl.NumberFormat(resolveAppLocale(locale), { maximumFractionDigits: 2 }).format(availability);
+};
+
 const getPropertiesDiagnosticValueState = (
   hasValue: boolean,
   diagnosticsLoading: boolean,