Fix SABnzbd downloads completing with no path set (race between active queue and history)

listenarr.infrastructure/DownloadClients/Sabnzbd/SabnzbdResponseMapper.cs

@@ -49,6 +49,17 @@ internal static class SabnzbdResponseMapper
         var mappedStatus = MapQueueStatus(status);
         var storagePath = GetString(slot, "storage");
         var explicitContentPath = string.IsNullOrWhiteSpace(storagePath) ? null : storagePath;
+
+        // SABnzbd reports an item as "Completed" in the active queue briefly before
+        // archiving it to history with the real storage path - active-queue slots don't
+        // reliably expose it (see comment below). Reporting completion here anyway lets
+        // QueueItemConverter mark the download Completed with no DownloadPath, which
+        // permanently blocks import. Excluding it instead makes the caller treat this
+        // download as missing from the active queue, which triggers a same-cycle history
+        // lookup - and history has the storage path by then.
+        if (mappedStatus == "completed" && explicitContentPath == null)
+            return null;
+
         var remotePath = explicitContentPath ?? (string.IsNullOrWhiteSpace(client.DownloadPath)
             ? null
             : client.DownloadPath);

tests/Features/Infrastructure/DownloadClients/Sabnzbd/SabnzbdResponseMapperTests.cs

@@ -0,0 +1,119 @@
+/*
+ * Listenarr - Audiobook Management System
+ * Copyright (C) 2024-2026 Listenarr Contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+namespace Listenarr.Tests.Features.Infrastructure.DownloadClients.Sabnzbd
+{
+    [Trait("Name", "SabnzbdResponseMapperTests")]
+    [Trait("Category", "SabnzbdResponseMapper")]
+    public sealed class SabnzbdResponseMapperTests
+    {
+        /// <summary>
+        /// Regression test for https://github.com/Listenarrs/Listenarr/issues/839
+        /// SABnzbd reports an item as "Completed" in the active queue before it is
+        /// archived to history with a real storage path. Mapping that slot to a
+        /// completed QueueItem let downloads reach DownloadStatus.Completed with an
+        /// empty DownloadPath, permanently blocking import.
+        /// </summary>
+        [Fact]
+        public void MapQueueSlotToQueueItem_CompletedStatusWithoutStorage_ReturnsNull()
+        {
+            // Given: an active-queue slot reporting Completed with no storage field yet
+            var client = new DownloadClientConfiguration { DownloadPath = "/downloads" };
+            using var document = System.Text.Json.JsonDocument.Parse(
+                """
+                {
+                  "nzo_id": "sab-race-1",
+                  "filename": "Book",
+                  "status": "Completed",
+                  "percentage": "100",
+                  "mb": "100",
+                  "mbleft": "0"
+                }
+                """);
+
+            // When
+            var item = SabnzbdResponseMapper.MapQueueSlotToQueueItem(
+                client,
+                document.RootElement,
+                configuredCategory: string.Empty,
+                speed: 0);
+
+            // Then: excluded rather than reported as a pathless completion
+            Assert.Null(item);
+        }
+
+        [Fact]
+        public void MapQueueSlotToQueueItem_CompletedStatusWithStorage_ReturnsCompletedItem()
+        {
+            // Given: an active-queue slot reporting Completed with a real storage path
+            var client = new DownloadClientConfiguration { DownloadPath = "/downloads" };
+            using var document = System.Text.Json.JsonDocument.Parse(
+                """
+                {
+                  "nzo_id": "sab-race-2",
+                  "filename": "Book",
+                  "status": "Completed",
+                  "percentage": "100",
+                  "mb": "100",
+                  "mbleft": "0",
+                  "storage": "/downloads/complete/Book"
+                }
+                """);
+
+            // When
+            var item = SabnzbdResponseMapper.MapQueueSlotToQueueItem(
+                client,
+                document.RootElement,
+                configuredCategory: string.Empty,
+                speed: 0);
+
+            // Then: a real storage path still resolves to a completed item, unaffected
+            Assert.NotNull(item);
+            Assert.Equal("completed", item!.Status);
+            Assert.Equal("/downloads/complete/Book", item.ContentPath);
+        }
+
+        [Fact]
+        public void MapQueueSlotToQueueItem_DownloadingStatusWithoutStorage_StillReturnsItem()
+        {
+            // Given: a genuinely still-downloading slot, which never carries storage
+            var client = new DownloadClientConfiguration { DownloadPath = "/downloads" };
+            using var document = System.Text.Json.JsonDocument.Parse(
+                """
+                {
+                  "nzo_id": "sab-race-3",
+                  "filename": "Book",
+                  "status": "Downloading",
+                  "percentage": "50",
+                  "mb": "100",
+                  "mbleft": "50"
+                }
+                """);
+
+            // When
+            var item = SabnzbdResponseMapper.MapQueueSlotToQueueItem(
+                client,
+                document.RootElement,
+                configuredCategory: string.Empty,
+                speed: 0);
+
+            // Then: the new guard only targets "completed" - in-progress items are unaffected
+            Assert.NotNull(item);
+            Assert.Equal("downloading", item!.Status);
+        }
+    }
+}