Fixed: Do not replace a file unless it contains the same episodes

src/NzbDrone.Core/DecisionEngine/Specifications/SameEpisodesGrabSpecification.cs

@@ -0,0 +1,31 @@
+using NLog;
+using NzbDrone.Core.IndexerSearch.Definitions;
+using NzbDrone.Core.Parser.Model;
+
+namespace NzbDrone.Core.DecisionEngine.Specifications
+{
+    public class SameEpisodesGrabSpecification : IDecisionEngineSpecification
+    {
+        private readonly SameEpisodesSpecification _sameEpisodesSpecification;
+        private readonly Logger _logger;
+
+        public SameEpisodesGrabSpecification(SameEpisodesSpecification sameEpisodesSpecification, Logger logger)
+        {
+            _sameEpisodesSpecification = sameEpisodesSpecification;
+            _logger = logger;
+        }
+
+        public RejectionType Type { get { return RejectionType.Permanent; } }
+
+        public virtual Decision IsSatisfiedBy(RemoteEpisode subject, SearchCriteriaBase searchCriteria)
+        {
+            if (_sameEpisodesSpecification.IsSatisfiedBy(subject.Episodes))
+            {
+                return Decision.Accept();
+            }
+
+            _logger.Debug("Episode file on disk contains more episodes than this release contains");
+            return Decision.Reject("Episode file on disk contains more episodes than this release contains");
+        }
+    }
+}