New: Use better page size for Newznab/Torznab (up to 100) when supported by the indexer

(cherry picked from commit ddb25b109575cc378462a1c3a64705f2003f01f0)

Closes #2181

src/NzbDrone.Core.Test/IndexerTests/NewznabTests/NewznabFixture.cs

@@ -65,12 +65,21 @@ namespace NzbDrone.Core.Test.IndexerTests.NewznabTests
         }
 
         [Test]
-        public void should_use_pagesize_reported_by_caps()
+        public void should_use_best_pagesize_reported_by_caps()
         {
             _caps.MaxPageSize = 30;
             _caps.DefaultPageSize = 25;
 
-            Subject.PageSize.Should().Be(25);
+            Subject.PageSize.Should().Be(30);
+        }
+
+        [Test]
+        public void should_not_use_pagesize_over_100_even_if_reported_in_caps()
+        {
+            _caps.MaxPageSize = 250;
+            _caps.DefaultPageSize = 25;
+
+            Subject.PageSize.Should().Be(100);
         }
 
         [Test]

src/NzbDrone.Core.Test/IndexerTests/TorznabTests/TorznabFixture.cs

@@ -103,12 +103,21 @@ namespace NzbDrone.Core.Test.IndexerTests.TorznabTests
         }
 
         [Test]
-        public void should_use_pagesize_reported_by_caps()
+        public void should_use_best_pagesize_reported_by_caps()
         {
             _caps.MaxPageSize = 30;
             _caps.DefaultPageSize = 25;
 
-            Subject.PageSize.Should().Be(25);
+            Subject.PageSize.Should().Be(30);
+        }
+
+        [Test]
+        public void should_not_use_pagesize_over_100_even_if_reported_in_caps()
+        {
+            _caps.MaxPageSize = 250;
+            _caps.DefaultPageSize = 25;
+
+            Subject.PageSize.Should().Be(100);
         }
 
         [TestCase("http://localhost:9117/", "/api")]

src/NzbDrone.Core/Indexers/Newznab/Newznab.cs

@@ -20,7 +20,7 @@ namespace NzbDrone.Core.Indexers.Newznab
 
         public override DownloadProtocol Protocol => DownloadProtocol.Usenet;
 
-        public override int PageSize => _capabilitiesProvider.GetCapabilities(Settings).DefaultPageSize;
+        public override int PageSize => Math.Min(100, Math.Max(_capabilitiesProvider.GetCapabilities(Settings).DefaultPageSize, _capabilitiesProvider.GetCapabilities(Settings).MaxPageSize));
 
         public override IIndexerRequestGenerator GetRequestGenerator()
         {

src/NzbDrone.Core/Indexers/Torznab/Torznab.cs

@@ -19,7 +19,7 @@ namespace NzbDrone.Core.Indexers.Torznab
         public override string Name => "Torznab";
 
         public override DownloadProtocol Protocol => DownloadProtocol.Torrent;
-        public override int PageSize => _capabilitiesProvider.GetCapabilities(Settings).DefaultPageSize;
+        public override int PageSize => Math.Min(100, Math.Max(_capabilitiesProvider.GetCapabilities(Settings).DefaultPageSize, _capabilitiesProvider.GetCapabilities(Settings).MaxPageSize));
 
         public override IIndexerRequestGenerator GetRequestGenerator()
         {