Fixed: Parsing of prefixed range multi-episode filenames

Fixes #2359

src/NzbDrone.Core.Test/ParserTests/MultiEpisodeParserFixture.cs

@@ -57,6 +57,8 @@ namespace NzbDrone.Core.Test.ParserTests
         [TestCase("Series Title.S6.E1-E2-E3.Episode Name.1080p.WEB-DL", "Series Title", 6, new[] { 1, 2, 3 })]
         [TestCase("Mad.Men.S05E01-E02.720p.5.1Ch.BluRay", "Mad Men", 5, new[] { 1, 2 })]
         [TestCase("Mad.Men.S05E01-02.720p.5.1Ch.BluRay", "Mad Men", 5, new[] { 1, 2 })]
+        [TestCase("S01E01-E03 - Episode Title.HDTV-720p", "", 1, new [] { 1, 2, 3 })]
+        [TestCase("1x01-x03 - Episode Title.HDTV-720p", "", 1, new [] { 1, 2, 3 })]
         //[TestCase("", "", , new [] {  })]
         public void should_parse_multiple_episodes(string postTitle, string title, int season, int[] episodes)
         {

src/NzbDrone.Core/Parser/Parser.cs

@@ -27,7 +27,7 @@ namespace NzbDrone.Core.Parser
                           RegexOptions.IgnoreCase | RegexOptions.Compiled),
 
                 //Episodes without a title, Multi (S01E04E05, 1x04x05, etc)
-                new Regex(@"^(?:S?(?<season>(?<!\d+)(?:\d{1,2}|\d{4})(?!\d+))(?:(?:[-_]|[ex])(?<episode>\d{2,3}(?!\d+))){2,})",
+                new Regex(@"^(?:S?(?<season>(?<!\d+)(?:\d{1,2}|\d{4})(?!\d+))(?:(?:[-_]|[ex]){1,2}(?<episode>\d{2,3}(?!\d+))){2,})",
                           RegexOptions.IgnoreCase | RegexOptions.Compiled),
 
                 //Episodes without a title, Single (S01E05, 1x05)