more nul fixes

Author: mgravell

src/RESPite/Messages/RespReader.cs

@@ -261,6 +261,9 @@ private readonly bool AggregateLengthIsSlow(int expected)
     /// </summary>
     public readonly bool IsAggregate => (_flags & RespFlags.IsAggregate) != 0;
 
+    internal readonly bool IsNonNullAggregate
+        => (_flags & (RespFlags.IsAggregate | RespFlags.IsNull)) == RespFlags.IsAggregate;
+
     /// <summary>
     /// Indicates whether this is a null value; this could be an explicit <see cref="RespPrefix.Null"/>,
     /// or a scalar or aggregate a negative reported length.
@@ -299,6 +302,7 @@ private readonly bool AggregateLengthIsSlow(int expected)
     internal int Delta() =>
         (_flags & (RespFlags.IsScalar | RespFlags.IsAggregate | RespFlags.IsStreaming | RespFlags.IsAttribute)) switch
         {
+            RespFlags.IsScalar | RespFlags.IsAggregate=> -1, // null has this
             RespFlags.IsScalar => -1,
             RespFlags.IsAggregate => _length - 1,
             RespFlags.IsAggregate | RespFlags.IsAttribute => _length,

src/RESPite/Messages/RespScanState.cs

@@ -33,7 +33,7 @@ no offsets are applied until we get back out of the outermost streaming aggregat
     private int _elementCount;
 
     /// <inheritdoc/>
-    public override string ToString() => $"{_prefix}, consumed: {_totalBytes} bytes, {_elementCount} nodes, complete: {IsComplete}";
+    public override string ToString() => $"{_prefix}, consumed: {_totalBytes} bytes, {_elementCount} nodes, complete: {IsComplete} ({_delta + 1} outstanding)";
 #else
     /// <inheritdoc/>
     public override string ToString() => _prefix.ToString();
@@ -132,7 +132,7 @@ private long ReadCore(ref RespReader reader, long startOffset = 0)
                 _prefix = reader.Prefix;
             }
 
-            if (reader.IsAggregate) ApplyAggregateRules(ref reader);
+            if (reader.IsNonNullAggregate) ApplyAggregateRules(ref reader);
 
             if (_streamingAggregateDepth == 0) _delta += reader.Delta();
         }