Complete fix inconsistency in youtube channel urls

It is not always possible to get the url in the form "https://www.youtube.com/channel/...", so a not has been added whenever that happens to be the case (i.e. only in InfoStreamItems).

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

@@ -50,7 +50,7 @@ public class YoutubePlaylistExtractor extends PlaylistExtractor {
         try {
             return doc.select("div[id=pl-header] h1[class=pl-header-title]").first().text();
         } catch (Exception e) {
-            throw new ParsingException("Could not get playlist name");
+            throw new ParsingException("Could not get playlist name", e);
         }
     }
 
@@ -59,7 +59,7 @@ public class YoutubePlaylistExtractor extends PlaylistExtractor {
         try {
             return doc.select("div[id=pl-header] div[class=pl-header-thumb] img").first().attr("abs:src");
         } catch (Exception e) {
-            throw new ParsingException("Could not get playlist thumbnail");
+            throw new ParsingException("Could not get playlist thumbnail", e);
         }
     }
 
@@ -72,9 +72,11 @@ public class YoutubePlaylistExtractor extends PlaylistExtractor {
     @Override
     public String getUploaderUrl() throws ParsingException {
         try {
-            return doc.select("ul[class=\"pl-header-details\"] li").first().select("a").first().attr("abs:href");
+            return YoutubeChannelExtractor.CHANNEL_URL_BASE +
+                    doc.select("button[class*=\"yt-uix-subscription-button\"]")
+                            .first().attr("data-channel-external-id");
         } catch (Exception e) {
-            throw new ParsingException("Could not get playlist uploader name");
+            throw new ParsingException("Could not get playlist uploader url", e);
         }
     }
 
@@ -83,7 +85,7 @@ public class YoutubePlaylistExtractor extends PlaylistExtractor {
         try {
             return doc.select("span[class=\"qualified-channel-title-text\"]").first().select("a").first().text();
         } catch (Exception e) {
-            throw new ParsingException("Could not get playlist uploader name");
+            throw new ParsingException("Could not get playlist uploader name", e);
         }
     }
 
@@ -92,7 +94,7 @@ public class YoutubePlaylistExtractor extends PlaylistExtractor {
         try {
             return doc.select("div[id=gh-banner] img[class=channel-header-profile-image]").first().attr("abs:src");
         } catch (Exception e) {
-            throw new ParsingException("Could not get playlist uploader avatar");
+            throw new ParsingException("Could not get playlist uploader avatar", e);
         }
     }
 
@@ -248,6 +250,8 @@ public class YoutubePlaylistExtractor extends PlaylistExtractor {
 
                 @Override
                 public String getUploaderUrl() throws ParsingException {
+                    // this url is not always in the form "/channel/..."
+                    // sometimes Youtube provides urls in the from "/user/..."
                     return getUploaderLink().attr("abs:href");
                 }
 

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

@@ -107,6 +107,8 @@ public class YoutubeStreamInfoItemExtractor implements StreamInfoItemExtractor {
 
     @Override
     public String getUploaderUrl() throws ParsingException {
+        // this url is not always in the form "/channel/..."
+        // sometimes Youtube provides urls in the from "/user/..."
         try {
             try {
                 return item.select("div[class=\"yt-lockup-byline\"]").first()
@@ -119,7 +121,7 @@ public class YoutubeStreamInfoItemExtractor implements StreamInfoItemExtractor {
                     .text().split(" - ")[0];
         } catch (Exception e) {
             System.out.println(item.html());
-            throw new ParsingException("Could not get uploader", e);
+            throw new ParsingException("Could not get uploader url", e);
         }
     }
 

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

@@ -126,6 +126,8 @@ public class YoutubeTrendingExtractor extends KioskExtractor<StreamInfoItem> {
                     }
 
                     private Element getUploaderLink() {
+                        // this url is not always in the form "/channel/..."
+                        // sometimes Youtube provides urls in the from "/user/..."
                         Element uploaderEl = el.select("div[class*=\"yt-lockup-byline \"]").first();
                         return uploaderEl.select("a").first();
                     }

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

@@ -100,7 +100,7 @@ public class YoutubePlaylistExtractorTest {
 
         @Test
         public void testUploaderUrl() throws Exception {
-            assertTrue(extractor.getUploaderUrl().contains("youtube.com"));
+            assertEquals("https://www.youtube.com/channel/UCs72iRpTEuwV3y6pdWYLgiw", extractor.getUploaderUrl());
         }
 
         @Test
@@ -185,8 +185,8 @@ public class YoutubePlaylistExtractorTest {
         public void testMoreRelatedItems() throws Exception {
             ListExtractor.InfoItemsPage<StreamInfoItem> currentPage
                     = defaultTestMoreItems(extractor, ServiceList.YouTube.getServiceId());
-            // Test for 2 more levels
 
+            // test for 2 more levels
             for (int i = 0; i < 2; i++) {
                 currentPage = extractor.getPage(currentPage.getNextPageUrl());
                 defaultTestListOfItems(YouTube.getServiceId(), currentPage.getItems(), currentPage.getErrors());
@@ -214,7 +214,7 @@ public class YoutubePlaylistExtractorTest {
 
         @Test
         public void testUploaderUrl() throws Exception {
-            assertTrue(extractor.getUploaderUrl().contains("youtube.com"));
+            assertEquals("https://www.youtube.com/channel/UCHSPWoY1J5fbDVbcnyeqwdw", extractor.getUploaderUrl());
         }
 
         @Test