Fixed parsing of mult-episode files with underscores

NzbDrone.Core.Test/ParserTests/ParserFixture.cs

@@ -149,6 +149,8 @@ namespace NzbDrone.Core.Test.ParserTests
         [TestCase("Breakout Kings - 2x09-2x10 - Served Cold [SDTV] ", "Breakout Kings", 2, new[] { 9, 10 })]
         [TestCase("Hell on Wheels S02E09 E10 HDTV x264 EVOLVE", "Hell on Wheels", 2, new[] { 9, 10 })]
         [TestCase("Hell.on.Wheels.S02E09-E10.720p.HDTV.x264-EVOLVE", "Hell on Wheels", 2, new[] { 9, 10 })]
+        [TestCase("Grey's Anatomy - 8x01_02 - Free Falling", "Grey's Anatomy", 8, new [] { 1,2 })]
+        [TestCase("8x01_02 - Free Falling", "", 8, new[] { 1, 2 })]
         public void TitleParse_multi(string postTitle, string title, int season, int[] episodes)
         {
             var result = Parser.Parser.ParseTitle(postTitle);

NzbDrone.Core/Parser/Parser.cs

@@ -30,11 +30,11 @@ namespace NzbDrone.Core.Parser
                           RegexOptions.IgnoreCase | RegexOptions.Compiled),
 
                 //Episodes without a title, Single (S01E05, 1x05) AND Multi (S01E04E05, 1x04x05, etc)
-                new Regex(@"^(?:S?(?<season>(?<!\d+)\d{1,2}(?!\d+))(?:(?:\-|[ex]|\W[ex]){1,2}(?<episode>\d{2}(?!\d+)))+)(\W+|_|$)(?!\\)",
+                new Regex(@"^(?:S?(?<season>(?<!\d+)\d{1,2}(?!\d+))(?:(?:\-|[ex]|\W[ex]|_){1,2}(?<episode>\d{2}(?!\d+)))+)(\W+|_|$)(?!\\)",
                           RegexOptions.IgnoreCase | RegexOptions.Compiled),
 
                 //Episodes with a title, Single episodes (S01E05, 1x05, etc) & Multi-episode (S01E05E06, S01E05-06, S01E05 E06, etc)
-                new Regex(@"^(?<title>.+?)(?:(\W|_)+S?(?<season>(?<!\d+)\d{1,2}(?!\d+))(?:(?:\-|[ex]|\W[ex]){1,2}(?<episode>\d{2}(?!\d+)))+)\W?(?!\\)",
+                new Regex(@"^(?<title>.+?)(?:(\W|_)+S?(?<season>(?<!\d+)\d{1,2}(?!\d+))(?:(?:\-|[ex]|\W[ex]|_){1,2}(?<episode>\d{2}(?!\d+)))+)\W?(?!\\)",
                           RegexOptions.IgnoreCase | RegexOptions.Compiled),
 
                 //Episodes over 99 (3-digits or more) (S01E105, S01E105E106, etc)