Put null checks in safe progress reporter.

Author: Woodrow-Fields

4.8.1/Numerics/Numerics.csproj

@@ -102,9 +102,7 @@
     <Reference Include="System.Text.Encodings.Web, Version=8.0.0.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
       <HintPath>..\..\8.0\packages\System.Text.Encodings.Web.8.0.0\lib\net462\System.Text.Encodings.Web.dll</HintPath>
     </Reference>
-    <Reference Include="System.Text.Json, Version=8.0.0.5, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
-      <HintPath>..\..\8.0\packages\System.Text.Json.8.0.5\lib\net462\System.Text.Json.dll</HintPath>
-    </Reference>
+    <Reference Include="System.Text.Json, Version=8.0.0.3, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL" />
     <Reference Include="System.Threading.Tasks.Extensions, Version=4.2.0.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
       <HintPath>..\..\8.0\packages\System.Threading.Tasks.Extensions.4.5.4\lib\net461\System.Threading.Tasks.Extensions.dll</HintPath>
     </Reference>

4.8.1/Numerics/Utilities/SafeProgressReporter.cs

@@ -204,15 +204,15 @@ protected void SetContext(SynchronizationContext context)
         /// </summary>
         public void IndicateTaskStart()
         {
-            _synchronizationContext.Post(new SendOrPostCallback(state => TaskStarted?.Invoke()), null);
+            _synchronizationContext?.Post(new SendOrPostCallback(state => TaskStarted?.Invoke()), null);
         }
 
         /// <summary>
         /// Indicate that the task has ended.
         /// </summary>
         public void IndicateTaskEnded()
         {
-            _synchronizationContext.Post(new SendOrPostCallback(state => TaskEnded?.Invoke()), null);
+            _synchronizationContext?.Post(new SendOrPostCallback(state => TaskEnded?.Invoke()), null);
         }
 
         /// <summary>
@@ -312,7 +312,7 @@ public SafeProgressReporter CreateProgressModifier(float fractionOfTotal, string
             child._cancellationTokenSource = _cancellationTokenSource;
             _subProgReporterCollection.Add(child);
             var invokeChildCreatedHandlers = new SendOrPostCallback(state => ChildReporterCreated?.Invoke(child));
-            _synchronizationContext.Post(invokeChildCreatedHandlers, child);
+            _synchronizationContext?.Post(invokeChildCreatedHandlers, child);
             return child;
         }
 
@@ -335,7 +335,7 @@ public void Report(double progress, string message, MessageType messageType)
         public void ReportProgress(double progress)
         {
             if (_previousProgress == progress) return;
-            _synchronizationContext.Post(_invokeProgressHandlers, new double[] { progress, _previousProgress });
+            _synchronizationContext?.Post(_invokeProgressHandlers, new double[] { progress, _previousProgress });
             _previousProgress = progress;
         }
 
@@ -346,7 +346,7 @@ public void ReportProgress(double progress)
         /// <param name="messageType">The message type.</param>
         public void ReportMessage(string message, MessageType messageType = MessageType.Status)
         {
-            _synchronizationContext.Post(_invokeMessageHandlers, new MessageContentStruct(message, messageType, this));
+            _synchronizationContext?.Post(_invokeMessageHandlers, new MessageContentStruct(message, messageType, this));
             MessageCount += 1;
             _previousMessage = message;
             _previousMessageType = messageType;
@@ -358,7 +358,7 @@ public void ReportMessage(string message, MessageType messageType = MessageType.
         /// <param name="message">The message to report.</param>
         protected void ReportMessage(MessageContentStruct message)
         {
-            _synchronizationContext.Post(_invokeMessageHandlers, message);
+            _synchronizationContext?.Post(_invokeMessageHandlers, message);
             MessageCount += 1;
             _previousMessage = message.Message;
             _previousMessageType = message.MessageType;