Fixes some issues discovered after new tests

Author: alex-kulakov

Orm/Xtensive.Orm/Orm/Providers/CommandProcessing/BatchingCommandProcessor.cs

@@ -182,16 +182,15 @@ private Command ExecuteBatch(int numberOfTasks, QueryRequest lastRequest, Comman
 
     private async Task<Command> ExecuteBatchAsync(int numberOfTasks, QueryRequest lastRequest, CommandProcessorContext context, CancellationToken token)
     {
-      var shouldReturnReader = lastRequest!=null;
-
-      if (numberOfTasks==0 && !shouldReturnReader) {
+      if (numberOfTasks==0 && lastRequest==null) {
         return null;
       }
 
       var tasksToProcess = context.ProcessingTasks;
 
       AllocateCommand(context);
 
+      var shouldReturnReader = false;
       try {
         while (numberOfTasks > 0 && tasksToProcess.Count > 0) {
           var task = tasksToProcess.Peek();

Orm/Xtensive.Orm/Orm/Session.QueryTasks.cs

@@ -53,9 +53,9 @@ internal async Task<bool> ExecuteDelayedUserQueriesAsync(bool skipPersist, Cance
     {
       token.ThrowIfCancellationRequested();
       if (!skipPersist)
-        Persist(PersistReason.Other);
+        Persist(PersistReason.Query);
       token.ThrowIfCancellationRequested();
-      return await ProcessUserDefinedDelayedQueriesAsync(token).ConfigureAwait(false);
+      return await ProcessUserDefinedDelayedQueriesAsync(false, token).ConfigureAwait(false);
     }
 
     private bool ProcessUserDefinedDelayedQueries(bool allowPartialExecution)
@@ -84,13 +84,13 @@ private bool ProcessInternalDelayedQueries(bool allowPartialExecution)
       }
     }
 
-    private async Task<bool> ProcessUserDefinedDelayedQueriesAsync(CancellationToken token)
+    private async Task<bool> ProcessUserDefinedDelayedQueriesAsync(bool allowPartialExecution, CancellationToken token)
     {
       if (userDefinedQueryTasks.Count==0)
         return false;
       var aliveTasks = userDefinedQueryTasks.Where(t => t.LifetimeToken.IsActive).ToList();
       userDefinedQueryTasks.Clear();
-      await Handler.ExecuteQueryTasksAsync(aliveTasks, false, token).ConfigureAwait(false);
+      await Handler.ExecuteQueryTasksAsync(aliveTasks, allowPartialExecution, token).ConfigureAwait(false);
       return true;
     }
   }

Orm/Xtensive.Orm/Orm/Session.cs

@@ -249,9 +249,9 @@ internal EnumerationContext CreateEnumerationContext()
 
     internal async Task<EnumerationContext> CreateEnumerationContextForAsyncQuery(CancellationToken token)
     {
-      Persist(PersistReason.Other);
+      Persist(PersistReason.Query);
       token.ThrowIfCancellationRequested();
-      await ProcessUserDefinedDelayedQueriesAsync(token).ConfigureAwait(false);
+      await ProcessUserDefinedDelayedQueriesAsync(true, token).ConfigureAwait(false);
       return new Providers.EnumerationContext(this, GetEnumerationContextOptions());
     }