Add LUCENENET-specific backport comment, fix test name

src/Lucene.Net.Tests/Index/TestIndexWriter.cs

@@ -818,23 +818,24 @@ public virtual void TestMaxThreadPriority()
 
         private Dictionary<String, String> GetCommitData(IndexWriter writer)
         {
-            Dictionary<String, String> data = new Dictionary<String, String>();            
+            Dictionary<String, String> data = new Dictionary<String, String>();
             foreach (var ent in writer.CommitData)
             {
                 data.Put(ent.Key, ent.Value);
-            }            
+            }
             return data;
         }
 
+        // LUCENENET-specific: backport fix and test from Lucene 9.9.0 (lucene#12626, lucene#12637)
         [Test]
-        public void testGetCommitDataFromOldSnapshot() 
+        public void TestGetCommitDataFromOldSnapshot()
         {
             Directory dir = NewDirectory();
             IndexWriterConfig conf = NewIndexWriterConfig(TEST_VERSION_CURRENT, new MockAnalyzer(Random)).SetMaxBufferedDocs(2).SetMergePolicy(NewLogMergePolicy());
             conf.SetIndexDeletionPolicy(new SnapshotDeletionPolicy(NoDeletionPolicy.INSTANCE));
             IndexWriter writer = new IndexWriter(dir, conf);
             writer.SetCommitData(
-            new Dictionary<String, String>() 
+            new Dictionary<String, String>()
             {
                 { "key", "value" },
             });
@@ -850,11 +851,11 @@ public void testGetCommitDataFromOldSnapshot()
             conf.SetIndexDeletionPolicy(new SnapshotDeletionPolicy(NoDeletionPolicy.INSTANCE));
             writer = new IndexWriter(dir, conf);
             writer.SetCommitData(
-            new Dictionary<String, String>() 
+            new Dictionary<String, String>()
               {
                     {"key", "value2" },
               });
-        
+
             assertEquals("value2", GetCommitData(writer).GetValueOrDefault("key"));
             writer.Dispose();
 

src/Lucene.Net/Index/SegmentInfos.cs

@@ -305,8 +305,8 @@ internal static string SegmentNumberToString(long segment, bool allowLegacyNames
         private JCG.List<SegmentCommitInfo> segments = new JCG.List<SegmentCommitInfo>();
 
         /// <summary>
-        /// If non-null, information about loading segments_N files 
-        /// will be printed here.</summary> 
+        /// If non-null, information about loading segments_N files
+        /// will be printed here.</summary>
         /// <seealso cref="InfoStream"/>
         private static TextWriter infoStream = null;
 
@@ -891,7 +891,7 @@ public object Clone()
         /// If non-null, information about retries when loading
         /// the segments file will be printed to this.
         /// </summary>
-        public static TextWriter InfoStream 
+        public static TextWriter InfoStream
         {
             set =>
                 // LUCENENET specific - use a SafeTextWriterWrapper to ensure that if the TextWriter
@@ -1452,6 +1452,7 @@ internal void Replace(SegmentInfos other)
         {
             RollbackSegmentInfos(other.AsList());
             lastGeneration = other.lastGeneration;
+            // LUCENENET-specific: backport fix from Lucene 9.9.0 (lucene#12626, lucene#12637)
             userData = other.userData;
         }
 
@@ -1612,7 +1613,7 @@ internal void Remove(int index)
         }
 
         /// <summary>
-        /// Return true if the provided 
+        /// Return true if the provided
         /// <see cref="SegmentCommitInfo"/> is contained.
         ///
         /// <para/><b>WARNING</b>: O(N) cost