Fix MoStratum for LT-21941

src/SIL.LCModel/DomainImpl/CmObject.cs

@@ -3413,6 +3413,10 @@ public virtual IEnumerable<ICmObject> ReferenceTargetCandidates(int flid)
 			var owner = ReferenceTargetOwner(flid) as ICmPossibilityList;
 			if (owner != null)
 				return owner.PossibilitiesOS.Cast<ICmObject>();
+			var mdc = m_cache.ServiceLocator.GetInstance<IFwMetaDataCacheManaged>();
+			int classId = mdc.GetDstClsId(flid);
+			if (classId == MoStratumTags.kClassId)
+				return m_cache.LangProject.MorphologicalDataOA.StrataOS;
 
 			var type = (CellarPropertyType)m_cache.MetaDataCache.GetFieldType(flid);
 			if (type == CellarPropertyType.ReferenceSequence || type == CellarPropertyType.ReferenceCollection)

src/SIL.LCModel/DomainImpl/OverridesLing_MoClasses.cs

@@ -4637,4 +4637,28 @@ public override ITsString ShortNameTSS
 		}
 
 	}
+
+	internal partial class MoStratum
+	{
+		/// <summary>
+		/// The shortest, non abbreviated label for the content of this object.
+		/// </summary>
+		public override string ShortName
+		{
+			get
+			{
+				var result = ShortNameTSS.Text;
+				return String.IsNullOrEmpty(result) ? Strings.ksQuestions : result;
+			}
+		}
+
+		/// <summary>
+		/// Shortest reasonable name for the object.
+		/// </summary>
+		public override ITsString ShortNameTSS
+		{
+			get { return Name.BestAnalysisVernacularAlternative; }
+		}
+
+	}
 }

tests/SIL.LCModel.Tests/DomainImpl/LingTests.cs

@@ -1,4 +1,4 @@
-// Copyright (c) 2002-2017 SIL International
+// Copyright (c) 2002-2017 SIL International
 // This software is licensed under the LGPL, version 2.1 or later
 // (http://www.gnu.org/licenses/lgpl-2.1.html)
 
@@ -135,6 +135,23 @@ public void NewStemNameHasFeatures()
 			pos.StemNamesOC.Add(msn);
 			Assert.That(msn.RegionsOC, Has.Count.EqualTo(1)); // can only be FsFeatStruc, there are no subclasses.
 		}
+
+		[Test]
+		public void Strata()
+		{
+			int ws = Cache.DefaultAnalWs;
+			IMoStratumFactory stratumFactory = Cache.ServiceLocator.GetInstance<IMoStratumFactory>();
+			IMoStratum stratum = stratumFactory.Create();
+			Cache.LangProject.MorphologicalDataOA.StrataOS.Add(stratum);
+			ITsString tss = TsStringUtils.MakeString("Clitic", ws);
+			stratum.Name.set_String(ws, tss);
+			Assert.That(stratum.ChooserNameTS.Text.Equals(tss.Text));
+			IPhRegularRuleFactory ruleFactory = Cache.ServiceLocator.GetInstance<IPhRegularRuleFactory>();
+			IPhRegularRule rule = ruleFactory.Create();
+			Cache.LangProject.PhonologicalDataOA.PhonRulesOS.Add(rule);
+			var strata = new HashSet<ICmObject>(rule.ReferenceTargetCandidates(PhRegularRuleTags.kflidInitialStratum));
+			Assert.That(strata.First().Equals(stratum));
+		}
 	}