Keep Issue.cs and TimelineRecord.cs aligned in terms of instantiation flow.

src/Runner.Worker/ActionCommandManager.cs

@@ -646,7 +646,8 @@ namespace GitHub.Runner.Worker
 
             string keyToExclude = Constants.Runner.InternalTelemetryIssueDataKey;
             var filteredDictionaryEntries = command.Properties
-                                                   .Where(kvp => !string.Equals(kvp.Key, keyToExclude, StringComparison.OrdinalIgnoreCase));
+                                                   .Where(kvp => !string.Equals(kvp.Key, keyToExclude, StringComparison.OrdinalIgnoreCase))
+                                                   .ToList();
 
             var metadata = new IssueMetadata(issueCategory, false, null, filteredDictionaryEntries);
             var issue = context.CreateIssue(this.Type, command.Data, metadata, true);

src/Sdk/DTWebApi/WebApi/Issue.cs

@@ -101,11 +101,6 @@ namespace GitHub.DistributedTask.WebApi
             m_serializedData = null;
         }
 
-        [DataMember(Name = "Data", EmitDefaultValue = false, Order = 4)]
-        private IDictionary<string, string> m_serializedData;
-
-        private IDictionary<string, string> m_data;
-
         /// <summary>
         /// DataContractSerializer bypasses all constructor logic and inline initialization!
         /// This method takes the place of a workhorse constructor for baseline initialization.
@@ -113,7 +108,14 @@ namespace GitHub.DistributedTask.WebApi
         /// </summary>
         private void EnsureInitialized()
         {
+            //Note that ?? is a short-circuiting operator.
             m_data = m_data ?? new Dictionary<string, string>(StringComparer.OrdinalIgnoreCase);
         }
+
+        [DataMember(Name = "Data", EmitDefaultValue = false, Order = 4)]
+        private IDictionary<string, string> m_serializedData;
+
+        private IDictionary<string, string> m_data;
+
     }
 }

src/Sdk/DTWebApi/WebApi/TimelineRecord.cs

@@ -10,11 +10,14 @@ namespace GitHub.DistributedTask.WebApi
     public sealed class TimelineRecord
     {
         public TimelineRecord()
+            : this(null)
         {
-            this.Attempt = 1;
         }
 
         private TimelineRecord(TimelineRecord recordToBeCloned)
+        {
+            this.EnsureInitialized();
+            if (recordToBeCloned != null)
             {
                 this.Attempt = recordToBeCloned.Attempt;
                 this.ChangeId = recordToBeCloned.ChangeId;
@@ -62,17 +65,21 @@ namespace GitHub.DistributedTask.WebApi
 
                 if (recordToBeCloned.m_issues?.Count > 0)
                 {
-                this.Issues.AddRange(recordToBeCloned.Issues.Select(i => i.Clone()));
+                    m_issues.AddRange(recordToBeCloned.m_issues.Select(i => i.Clone()));
                 }
 
                 if (recordToBeCloned.m_previousAttempts?.Count > 0)
                 {
-                this.PreviousAttempts.AddRange(recordToBeCloned.PreviousAttempts);
+                    m_previousAttempts.AddRange(recordToBeCloned.m_previousAttempts);
                 }
 
                 if (recordToBeCloned.m_variables?.Count > 0)
                 {
-                this.m_variables = recordToBeCloned.Variables.ToDictionary(k => k.Key, v => v.Value.Clone());
+                    // Don't pave over the case-insensitive Dictionary we initialized above.
+                    foreach (var kvp in recordToBeCloned.m_variables) {
+                        m_variables[kvp.Key] = kvp.Value.Clone();
+                    }
+                }
             }
         }
 
@@ -234,10 +241,6 @@ namespace GitHub.DistributedTask.WebApi
         {
             get
             {
-                if (m_issues == null)
-                {
-                    m_issues = new List<Issue>();
-                }
                 return m_issues;
             }
         }
@@ -274,22 +277,14 @@ namespace GitHub.DistributedTask.WebApi
         {
             get
             {
-                if (m_previousAttempts == null)
-                {
-                    m_previousAttempts = new List<TimelineAttempt>();
-                }
                 return m_previousAttempts;
             }
         }
 
-        public IDictionary<String, VariableValue> Variables
+        public IDictionary<string, VariableValue> Variables
         {
             get
             {
-                if (m_variables == null)
-                {
-                    m_variables = new Dictionary<String, VariableValue>(StringComparer.OrdinalIgnoreCase);
-                }
                 return m_variables;
             }
         }
@@ -299,11 +294,32 @@ namespace GitHub.DistributedTask.WebApi
             return new TimelineRecord(this);
         }
 
+        [OnDeserialized]
+        private void OnDeserialized(StreamingContext context)
+        {
+            this.EnsureInitialized();
+        }
+
+        /// <summary>
+        /// DataContractSerializer bypasses all constructor logic and inline initialization!
+        /// This method takes the place of a workhorse constructor for baseline initialization.
+        /// The expectation is for this logic to be accessible to constructors and also to the OnDeserialized helper.
+        /// </summary>
+        private void EnsureInitialized()
+        {
+            //Note that ?? is a short-circuiting operator.
+            m_issues = m_issues ?? new List<Issue>();
+            m_variables = m_variables ?? new Dictionary<string, VariableValue>(StringComparer.OrdinalIgnoreCase);
+            m_previousAttempts = m_previousAttempts ?? new List<TimelineAttempt>();
+            this.Attempt = Math.Max(this.Attempt, 1);
+        }
+
+
         [DataMember(Name = "Issues", EmitDefaultValue = false, Order = 60)]
         private List<Issue> m_issues;
 
         [DataMember(Name = "Variables", EmitDefaultValue = false, Order = 80)]
-        private Dictionary<String, VariableValue> m_variables;
+        private Dictionary<string, VariableValue> m_variables;
 
         [DataMember(Name = "PreviousAttempts", EmitDefaultValue = false, Order = 120)]
         private List<TimelineAttempt> m_previousAttempts;