[YouTube] Fallback to playlist uploader on course playlists

Course playlists videos do not contain the uploader. This leads to an exception
being thrown when trying to extract the uploader values. We can fallback to the
playlist uploader values, as every video is uploaded by the playlist uploader.

Closes: #1425

Author: FineFindus

extractor/src/main/java/org/schabi/newpipe/extractor/services/youtube/extractors/YoutubePlaylistExtractor.java

@@ -425,8 +425,27 @@ private void collectStreamsFrom(@Nonnull final StreamInfoItemsCollector collecto
                 .map(JsonObject.class::cast)
                 .forEach(video -> {
                     if (video.has(PLAYLIST_VIDEO_RENDERER)) {
+                        final PlaylistExtractor playlistExtractor = this;
                         collector.commit(new YoutubeStreamInfoItemExtractor(
-                                video.getObject(PLAYLIST_VIDEO_RENDERER), timeAgoParser));
+                            video.getObject(PLAYLIST_VIDEO_RENDERER), timeAgoParser) {
+                                @Override
+                                public String getUploaderName() throws ParsingException {
+                                    try {
+                                        return super.getUploaderName();
+                                    } catch (final ParsingException e) {
+                                        return playlistExtractor.getUploaderName();
+                                    }
+                                }
+
+                                @Override
+                                public String getUploaderUrl() throws ParsingException {
+                                    try {
+                                        return super.getUploaderUrl();
+                                    } catch (final ParsingException e) {
+                                        return playlistExtractor.getUploaderUrl();
+                                    }
+                                }
+                            });
                     } else if (video.has(RICH_ITEM_RENDERER)) {
                         final JsonObject richItemRenderer = video.getObject(RICH_ITEM_RENDERER);
                         if (richItemRenderer.has("content")) {

extractor/src/test/java/org/schabi/newpipe/extractor/services/youtube/YoutubePlaylistExtractorTest.java

@@ -513,7 +513,7 @@ public static class MembersOnlyTests implements InitYoutubeTest {
         void testOnlyMembersOnlyVideos() throws Exception {
             final YoutubePlaylistExtractor extractor = (YoutubePlaylistExtractor) YouTube
                     .getPlaylistExtractor(
-                // auto-generated playlist with only membersOnly videos
+                // autogenerated playlist with only membersOnly videos
                             "https://www.youtube.com/playlist?list=UUMOQuLXlFNAeDJMSmuzHU5axw");
             extractor.fetchPage();
 
@@ -530,4 +530,23 @@ void testOnlyMembersOnlyVideos() throws Exception {
             assertTrue(membershipVideos.isEmpty());
         }
     }
+
+    public static class CoursePlaylistTest implements InitYoutubeTest {
+
+        @Test
+        void uploaderName() throws Exception {
+            final YoutubePlaylistExtractor extractor = (YoutubePlaylistExtractor) YouTube
+                    .getPlaylistExtractor(
+                            "https://www.youtube.com/playlist?list=PLWxziGKTUvQFIsbbFcTZz7jOT4TMGnZBh");
+            extractor.fetchPage();
+
+            final List<StreamInfoItem> allItems = extractor.getInitialPage().getItems()
+                    .stream()
+                    .filter(StreamInfoItem.class::isInstance)
+                    .map(StreamInfoItem.class::cast)
+                    .collect(Collectors.toUnmodifiableList());
+            assertEquals(14, allItems.size());
+            assertEquals(extractor.getUploaderName(),  allItems.get(0).getUploaderName());
+        }
+    }
 }

extractor/src/test/resources/mocks/v1/org/schabi/newpipe/extractor/services/youtube/youtubeplaylistextractor/courseplaylist/generated_mock_0.json

@@ -0,0 +1,101 @@
+{
+  "request": {
+    "httpMethod": "GET",
+    "url": "https://www.youtube.com/sw.js",
+    "headers": {
+      "Origin": [
+        "https://www.youtube.com"
+      ],
+      "Referer": [
+        "https://www.youtube.com"
+      ],
+      "Accept-Language": [
+        "en-GB, en;q\u003d0.9"
+      ]
+    },
+    "localization": {
+      "languageCode": "en",
+      "countryCode": "GB"
+    }
+  },
+  "response": {
+    "responseCode": 200,
+    "responseMessage": "",
+    "responseHeaders": {
+      "accept-ch": [
+        "Sec-CH-Viewport-Width, Sec-CH-DPR, Device-Memory"
+      ],
+      "access-control-allow-credentials": [
+        "true"
+      ],
+      "access-control-allow-origin": [
+        "https://www.youtube.com"
+      ],
+      "alt-svc": [
+        "h3\u003d\":443\"; ma\u003d2592000,h3-29\u003d\":443\"; ma\u003d2592000"
+      ],
+      "cache-control": [
+        "private, max-age\u003d0"
+      ],
+      "content-security-policy": [
+        "script-src \u0027unsafe-eval\u0027 \u0027self\u0027 \u0027unsafe-inline\u0027 https://www.google.com https://apis.google.com https://ssl.gstatic.com https://www.gstatic.com https://www.googletagmanager.com https://www.google-analytics.com https://*.youtube.com https://*.google.com https://*.gstatic.com https://youtube.com https://www.youtube.com https://google.com https://*.doubleclick.net https://*.googleapis.com https://www.googleadservices.com https://tpc.googlesyndication.com https://www.youtubekids.com https://www.youtube-nocookie.com https://www.youtubeeducation.com https://www-onepick-opensocial.googleusercontent.com;report-uri https://csp.withgoogle.com/csp/youtube_main/allowlist",
+        "require-trusted-types-for \u0027script\u0027"
+      ],
+      "content-type": [
+        "text/javascript; charset\u003dutf-8"
+      ],
+      "cross-origin-opener-policy": [
+        "same-origin; report-to\u003d\"youtube_main\""
+      ],
+      "date": [
+        "Mon, 05 Jan 2026 19:58:36 GMT"
+      ],
+      "document-policy": [
+        "include-js-call-stacks-in-crash-reports"
+      ],
+      "expires": [
+        "Mon, 05 Jan 2026 19:58:36 GMT"
+      ],
+      "origin-trial": [
+        "AmhMBR6zCLzDDxpW+HfpP67BqwIknWnyMOXOQGfzYswFmJe+fgaI6XZgAzcxOrzNtP7hEDsOo1jdjFnVr2IdxQ4AAAB4eyJvcmlnaW4iOiJodHRwczovL3lvdXR1YmUuY29tOjQ0MyIsImZlYXR1cmUiOiJXZWJWaWV3WFJlcXVlc3RlZFdpdGhEZXByZWNhdGlvbiIsImV4cGlyeSI6MTc1ODA2NzE5OSwiaXNTdWJkb21haW4iOnRydWV9",
+        "AiDEBptUfVeO93q48VdVMe/ubupazdAl8AaHP+NBzdnW8quUcHdzJUyGSfrmtpKJu7EOvwRp9ug2rEo3XU+WMAMAAAB2eyJvcmlnaW4iOiJodHRwczovL3lvdXR1YmUuY29tOjQ0MyIsImZlYXR1cmUiOiJEZXZpY2VCb3VuZFNlc3Npb25DcmVkZW50aWFsczIiLCJleHBpcnkiOjE3NzQzMTA0MDAsImlzU3ViZG9tYWluIjp0cnVlfQ\u003d\u003d"
+      ],
+      "p3p": [
+        "CP\u003d\"This is not a P3P policy! See http://support.google.com/accounts/answer/151657?hl\u003den-GB for more info.\""
+      ],
+      "permissions-policy": [
+        "ch-ua-arch\u003d*, ch-ua-bitness\u003d*, ch-ua-full-version\u003d*, ch-ua-full-version-list\u003d*, ch-ua-model\u003d*, ch-ua-wow64\u003d*, ch-ua-form-factors\u003d*, ch-ua-platform\u003d*, ch-ua-platform-version\u003d*"
+      ],
+      "report-to": [
+        "{\"group\":\"youtube_main\",\"max_age\":2592000,\"endpoints\":[{\"url\":\"https://csp.withgoogle.com/csp/report-to/youtube_main\"}]}"
+      ],
+      "reporting-endpoints": [
+        "default\u003d\"/web-reports?context\u003deJwNzHtozXEcxnE_77DOOTvn_H7fz9dtCoclcdbZMlLmbiSH5ZLZaLPZ3GazOecYoYRYSYkwc1thMkz-ENaMTMvkOsslQ3JJlmtYIb5_vP54np4e17VuK_6tsgZPK7bObyy1Fg4ps6bcW2PtTI9YP09GrLP1ESvcFrU6BsSs7EDMOtAWs4pelltH_Jldy_tmdq3PclFY6OJHpYuvz12Uf3aRPcxN63Q3HTPdrFzo5mKNm_oLbtrfu_mS62FE1MOHjHgaKuMZPtfLqcteMpq97DY-_fWycbSPkWk-YgU-3DEfByt8JO_3EVfto1eLj4bBfuJy_biMh1V-nv_ys0jZ7Eq1OTTPpj3HJrzUZsMGm63GxF02Y_fZNJ62SThnox7Z9Ptg87rT5lm6w7_pDjWzHcLZDu9KHG40OqTddRjz0CHxsYP_qUPorUPvToe4HgpHFOEERW1_hQooapIUwVRF4XhFdJai06jKUkzKVrhKFHuMF6WKbWUmb1FM2K5YX6O4XqvgjOKWkX9JkXtFcafZ9LcV6U8U64y6p4rEj4q93xQjvitKfyv-GHiEzV4ho5cwb7jQkS58Mr4a8VMFKyzMMAJLhNplQnWRkBcR_kTNvlLYZFw1tlUJ544J948Lrca-M8LAeiGrQVjUKPy6LuTfENqbhKabwsdmIbNFmHxXqDAu3zfdA6NV2NEmrHomnDQqXgpD35gPw34rpH0Xcn4Ii43DXTTjuml-ezQT4zUJfs0CR1NnbFKaNtFM7qkZ1Fvj9NEcNe4laKYENHmJmuqQ5uoozYk5mjnzzcYT11H3paW7_9WbplorEFxXEo1E8wqS1hbkBQvLSoojwYLiJcH8suWR5fmLi3JSQimpySkpyUnJoZzVof8Zrtt2\""
+      ],
+      "server": [
+        "ESF"
+      ],
+      "set-cookie": [
+        "YSC\u003d53hT5wtfQ8Q; Domain\u003d.youtube.com; Path\u003d/; Secure; HttpOnly; SameSite\u003dnone",
+        "VISITOR_INFO1_LIVE\u003d; Domain\u003d.youtube.com; Expires\u003dTue, 11-Apr-2023 19:58:36 GMT; Path\u003d/; Secure; HttpOnly; SameSite\u003dnone"
+      ],
+      "strict-transport-security": [
+        "max-age\u003d31536000"
+      ],
+      "vary": [
+        "Sec-CH-Viewport-Width, Sec-CH-DPR, Device-Memory"
+      ],
+      "x-content-type-options": [
+        "nosniff"
+      ],
+      "x-frame-options": [
+        "SAMEORIGIN"
+      ],
+      "x-xss-protection": [
+        "0"
+      ]
+    },
+    "responseBody": "\n  self.addEventListener(\u0027install\u0027, event \u003d\u003e {\n    event.waitUntil(self.skipWaiting());\n  });\n  self.addEventListener(\u0027activate\u0027, event \u003d\u003e {\n    event.waitUntil(\n      self.clients.claim().then(() \u003d\u003e self.registration.unregister()));\n  });\n  ",
+    "latestUrl": "https://www.youtube.com/sw.js"
+  }
+}