Fixed: 3 digit season/episode numbers followed by an underscore

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

@@ -85,6 +85,7 @@ namespace NzbDrone.Core.Test.ParserTests
         [TestCase("2009x09 [SDTV].avi", "", 2009, 9)]
         [TestCase("S2009E09 [SDTV].avi", "", 2009, 9)]
         [TestCase("Shark Week S2009E09 [SDTV].avi", "Shark Week", 2009, 9)]
+        [TestCase("St_Elsewhere_209_Aids_And_Comfort", "St Elsewhere", 2, 9)]
         //[TestCase("", "", 0, 0)]
         public void should_parse_single_episode(string postTitle, string title, int seasonNumber, int episodeNumber)
         {

src/NzbDrone.Core/Parser/Parser.cs

@@ -59,7 +59,7 @@ namespace NzbDrone.Core.Parser
                           RegexOptions.IgnoreCase | RegexOptions.Compiled),
 
                 //Supports 103/113 naming
-                new Regex(@"^(?<title>.+?)?(?:\W?(?<season>(?<!\d+)[1-9])(?<episode>[1-9][0-9]|[0][1-9])(?!\w|\d+))+",
+                new Regex(@"^(?<title>.+?)?(?:(?:\W?|_)(?<season>(?<!\d+)[1-9])(?<episode>[1-9][0-9]|[0][1-9])(?![a-z]|\d+))+",
                           RegexOptions.IgnoreCase | RegexOptions.Compiled),
 
                 //Mini-Series, treated as season 1, episodes are labelled as Part01, Part 01, Part.1
@@ -79,7 +79,7 @@ namespace NzbDrone.Core.Parser
                           RegexOptions.IgnoreCase | RegexOptions.Compiled),
 
                 //Supports 1103/1113 naming
-                new Regex(@"^(?<title>.+?)?(?:\W?(?<season>(?<!\d+|\(|\[|e|x)\d{2})(?<episode>(?<!e|x)\d{2}(?!p|i|\d+|\)|\]|\W\d+)))+(\W+|_|$)(?!\\)",
+                new Regex(@"^(?<title>.+?)?(?:(?:\W|_)?(?<season>(?<!\d+|\(|\[|e|x)\d{2})(?<episode>(?<!e|x)\d{2}(?!p|i|\d+|\)|\]|\W\d+)))+(\W+|_|$)(?!\\)",
                           RegexOptions.IgnoreCase | RegexOptions.Compiled),
 
                 //4-digit episode number