TV metadata lookup: prefer season/episode on search

over subtitle search if inetref is provided.

The search for TV shows with 'inetref' & 'subtitle' is ambiguous if the
same subtitle exists multiple times, like "Episode 1" available for
multiple seasons.

If data for 'season' and 'episode' numbers are available, use it at
first instance, because these data are unique.

Refs #473

(cherry picked from commit 2311368)

mythtv/libs/libmythmetadata/metadatadownload.cpp

@@ -635,8 +635,8 @@ MetadataLookupList MetadataDownload::handleMovie(MetadataLookup *lookup)
  * attempt to find television data via the following (in order)
  * 1- Local MXML: already done before
  * 2- Local NFO: already done
- * 3- By inetref with subtitle
- * 4- By inetref with season and episode
+ * 3- By inetref with season and episode
+ * 4- By inetref with subtitle
  * 5- By inetref
  * 6- By title and subtitle
  * 7- By title
@@ -655,17 +655,17 @@ MetadataLookupList MetadataDownload::handleTelevision(MetadataLookup *lookup)
     {
         // with inetref
         lookup->SetStep(kLookupData);
-        if (!lookup->GetSubtitle().isEmpty())
+        if (lookup->GetSeason() || lookup->GetEpisode())
         {
-            list = grabber.SearchSubtitle(lookup->GetInetref(),
-                                          lookup->GetBaseTitle() /* unused */,
-                                          lookup->GetSubtitle(), lookup, false);
+            list = grabber.LookupData(lookup->GetInetref(), lookup->GetSeason(),
+                                      lookup->GetEpisode(), lookup);
         }
 
-        if (list.isEmpty() && (lookup->GetSeason() || lookup->GetEpisode()))
+        if (list.isEmpty() && (!lookup->GetSubtitle().isEmpty()))
         {
-            list = grabber.LookupData(lookup->GetInetref(), lookup->GetSeason(),
-                                      lookup->GetEpisode(), lookup);
+            list = grabber.SearchSubtitle(lookup->GetInetref(),
+                                          lookup->GetBaseTitle() /* unused */,
+                                          lookup->GetSubtitle(), lookup, false);
         }
 
         if (list.isEmpty() && !lookup->GetCollectionref().isEmpty())