Try to fix new exceptions

Author: tobias-tengler

src/HotChocolate/Core/src/Features/PooledFeatureCollection.cs

@@ -161,6 +161,8 @@ public void Reset()
         }
 
         _features.Clear();
+        _defaults = null;
+        _containerRevision = 0;
     }
 
     /// <inheritdoc />

src/HotChocolate/Core/src/Validation/DocumentValidator.cs

@@ -141,7 +141,7 @@ public DocumentValidatorResult Validate(
         }
         finally
         {
-            ReturnContext(context);
+            _contextPool.Return(context);
         }
     }
 
@@ -155,9 +155,4 @@ private DocumentValidatorContext RentContext(
         context.Initialize(schema, documentId, document, _maxAllowedErrors, features);
         return context;
     }
-
-    private void ReturnContext(DocumentValidatorContext context)
-    {
-        _contextPool.Return(context);
-    }
 }

src/HotChocolate/Core/src/Validation/Rules/FieldVisitor.cs

@@ -524,21 +524,15 @@ protected internal override void Reset()
 
             if (_buffers.Count > 1)
             {
-                var buffer = _buffers.Pop();
-                buffer.Clear();
-
-                for (var i = 0; i < _buffers.Count; i++)
+                for (var i = 1; i < _buffers.Count; i++)
                 {
                     s_fieldInfoPool.Return(_buffers[i]);
                 }
 
-                _buffers.Clear();
-                _buffers.Push(buffer);
-            }
-            else
-            {
-                _buffers[0].Clear();
+                _buffers.RemoveRange(1, _buffers.Count - 1);
             }
+
+            _buffers[0].Clear();
         }
     }
 }

src/HotChocolate/CostAnalysis/src/CostAnalysis/CostAnalyzer.cs

@@ -370,26 +370,19 @@ protected internal override void Reset()
         FieldSets.Clear();
         SelectionSetCost.Clear();
         Processed.Clear();
+        InputCostVisitorContext.Clear();
 
         if (_buffers.Count > 1)
         {
-            var buffer = _buffers.Pop();
-            buffer.Clear();
-
-            for (var i = 0; i < _buffers.Count; i++)
+            for (var i = 1; i < _buffers.Count; i++)
             {
                 s_fieldInfoPool.Return(_buffers[i]);
             }
 
-            _buffers.Clear();
-            _buffers.Push(buffer);
-        }
-        else
-        {
-            _buffers[0].Clear();
+            _buffers.RemoveRange(1, _buffers.Count - 1);
         }
 
-        InputCostVisitorContext.Clear();
+        _buffers[0].Clear();
     }
 }