fixup! Fix breaking API changes inadvertently introduced into the 1.0.1 branch

Only set _currentContext on obsolete path

Author: bricelam

src/Microsoft.EntityFrameworkCore.Relational/Query/Internal/AsyncGroupJoinInclude.cs

@@ -61,7 +61,7 @@ public virtual void SetPrevious([NotNull] AsyncGroupJoinInclude previous)
             "This method is obsolete and will be removed in the 1.1.0 release. Use CreateIncludeContext instead.",
              error: true)]
         public virtual void Initialize([NotNull] RelationalQueryContext queryContext)
-            => CreateIncludeContext(queryContext);
+            => _currentContext = CreateIncludeContext(queryContext);
 
         /// <summary>
         ///     This API supports the Entity Framework Core infrastructure and is not intended to be used
@@ -81,7 +81,7 @@ var asyncGroupJoinIncludeContext
                 asyncGroupJoinIncludeContext.SetPrevious(_previous.CreateIncludeContext(queryContext));
             }
 
-            return _currentContext = asyncGroupJoinIncludeContext;
+            return asyncGroupJoinIncludeContext;
         }
 
         /// <summary>
@@ -92,7 +92,7 @@ var asyncGroupJoinIncludeContext
             "This method is obsolete and will be removed in the 1.1.0 release. Use IncludeAsync on the object returned by CreateIncludeContext instead.",
              error: true)]
         public virtual Task IncludeAsync([CanBeNull] object entity, CancellationToken cancellationToken)
-            => _currentContext.IncludeAsync(entity, cancellationToken);
+            => _currentContext?.IncludeAsync(entity, cancellationToken) ?? Task.FromResult(0);
 
         /// <summary>
         ///     This API supports the Entity Framework Core infrastructure and is not intended to be used

src/Microsoft.EntityFrameworkCore.Relational/Query/Internal/GroupJoinInclude.cs

@@ -60,7 +60,7 @@ public virtual void SetPrevious([NotNull] GroupJoinInclude previous)
             "This method is obsolete and will be removed in the 1.1.0 release. Use CreateIncludeContext instead.",
              error: true)]
         public virtual void Initialize([NotNull] RelationalQueryContext queryContext)
-            => CreateIncludeContext(queryContext);
+            => _currentContext = CreateIncludeContext(queryContext);
 
         /// <summary>
         ///     This API supports the Entity Framework Core infrastructure and is not intended to be used
@@ -80,7 +80,7 @@ var groupJoinIncludeContext
                 groupJoinIncludeContext.SetPrevious(_previous.CreateIncludeContext(queryContext));
             }
 
-            return _currentContext = groupJoinIncludeContext;
+            return groupJoinIncludeContext;
         }
 
         /// <summary>
@@ -91,7 +91,7 @@ var groupJoinIncludeContext
             "This method is obsolete and will be removed in the 1.1.0 release. Use Include on the object returned by CreateIncludeContext instead.",
              error: true)]
         public virtual void Include([CanBeNull] object entity)
-            => _currentContext.Include(entity);
+            => _currentContext?.Include(entity);
 
         /// <summary>
         ///     This API supports the Entity Framework Core infrastructure and is not intended to be used