fixes #1044, revert the changes for duplicated left JOIN changes. Add…

… the regression tests. Update the version to 8.2.3 (#1045)

src/Microsoft.AspNetCore.OData/Microsoft.AspNetCore.OData.xml

@@ -9624,11 +9624,6 @@
             Basically for $compute in $select and $expand
             </summary>
         </member>
-        <member name="P:Microsoft.AspNetCore.OData.Query.Expressions.QueryBinderContext.QueryProvider">
-            <summary>
-            Gets or sets the query provider.
-            </summary>
-        </member>
         <member name="M:Microsoft.AspNetCore.OData.Query.Expressions.QueryBinderContext.GetParameter(System.String)">
             <summary>
             Gets the parameter using parameter name.

src/Microsoft.AspNetCore.OData/Query/Expressions/BinderExtensions.cs

@@ -273,11 +273,6 @@ public static IQueryable ApplyBind(this ISelectExpandBinder binder, IQueryable s
                 throw Error.ArgumentNull(nameof(context));
             }
 
-            if (string.IsNullOrEmpty(context.QueryProvider))
-            {
-                context.QueryProvider = source.Provider.GetType().Namespace;
-            }
-
             Type elementType = context.ElementClrType;
 
             LambdaExpression projectionLambda = binder.BindSelectExpand(selectExpandClause, context) as LambdaExpression;

src/Microsoft.AspNetCore.OData/Query/Expressions/QueryBinderContext.cs

@@ -100,8 +100,6 @@ public QueryBinderContext(QueryBinderContext context, ODataQuerySettings querySe
 
             ElementType = Model.GetEdmTypeReference(ElementClrType)?.Definition;
 
-            QueryProvider = context.QueryProvider;
-
             if (ElementType == null)
             {
                 throw new ODataException(Error.Format(SRResources.ClrTypeNotInModel, ElementClrType.FullName));
@@ -170,11 +168,6 @@ public QueryBinderContext(QueryBinderContext context, ODataQuerySettings querySe
         /// </summary>
         public Expression Source { get;set; }
 
-        /// <summary>
-        /// Gets or sets the query provider.
-        /// </summary>
-        internal string QueryProvider { get; set; }
-
         /// <summary>
         /// Gets the parameter using parameter name.
         /// </summary>

src/Microsoft.AspNetCore.OData/Query/Expressions/SelectExpandBinder.cs

@@ -368,23 +368,9 @@ internal Expression ProjectElement(QueryBinderContext context, Expression source
             bool isSelectedAll = IsSelectAll(selectExpandClause);
             if (isSelectedAll)
             {
-                // If we have an EF query provider, then we remove the non-structural properties. The reason for this is to avoid 
-                // Creating an expression that will generate duplicate LEFT joins when a LEFT join already exists in the IQueryable 
-                // as observed here: https://github.com/OData/AspNetCoreOData/issues/497
-
-                Expression updatedExpression = null;
-                if (IsEfQueryProvider(context))
-                {
-                    updatedExpression = SelectExpandBinder.RemoveNonStructucalProperties(context, source, structuredType);
-                }
-                else 
-                {
-                    updatedExpression = source;
-                }
-
                 // Initialize property 'Instance' on the wrapper class
                 wrapperProperty = wrapperType.GetProperty("Instance");
-                wrapperTypeMemberAssignments.Add(Expression.Bind(wrapperProperty, updatedExpression));
+                wrapperTypeMemberAssignments.Add(Expression.Bind(wrapperProperty, source));
 
                 wrapperProperty = wrapperType.GetProperty("UseInstanceForProperties");
                 wrapperTypeMemberAssignments.Add(Expression.Bind(wrapperProperty, Expression.Constant(true)));
@@ -441,52 +427,6 @@ internal Expression ProjectElement(QueryBinderContext context, Expression source
             return Expression.MemberInit(Expression.New(wrapperType), wrapperTypeMemberAssignments);
         }
 
-        // Generates the expression
-        //      { Instance = new Customer() {Id = $it.Id, Name= $it.Name}}
-        private static Expression RemoveNonStructucalProperties(QueryBinderContext context, Expression source, IEdmStructuredType structuredType)
-        {
-            IEdmModel model = context.Model;
-            Expression updatedSource = null;
-
-            Type elementType = source.Type;
-            IEnumerable<IEdmStructuralProperty> structuralProperties = structuredType.StructuralProperties();
-
-            PropertyInfo[] props = elementType.GetProperties();
-            List<MemberBinding> bindings = new List<MemberBinding>();
-
-            foreach (PropertyInfo prop in props)
-            {
-                foreach (var sp in structuralProperties)
-                {
-                    if (prop.CanWrite && model.GetClrPropertyName(sp) == prop.Name)
-                    {
-                        MemberExpression propertyExpression = Expression.Property(source, prop);
-                        bindings.Add(Expression.Bind(prop, propertyExpression));
-                        break;
-                    }
-                }
-            }
-
-            NewExpression newExpression = Expression.New(source.Type);
-            updatedSource = Expression.MemberInit(newExpression, bindings);
-
-            return updatedSource;     
-        }
-
-        private bool IsEfQueryProvider(QueryBinderContext context)
-        {
-            if (context.QueryProvider != null &&
-                context.QueryProvider == HandleNullPropagationOptionHelper.EntityFrameworkQueryProviderNamespace ||
-                context.QueryProvider == HandleNullPropagationOptionHelper.ObjectContextQueryProviderNamespaceEF5 ||
-                context.QueryProvider == HandleNullPropagationOptionHelper.ObjectContextQueryProviderNamespaceEF6 ||
-                context.QueryProvider == HandleNullPropagationOptionHelper.ObjectContextQueryProviderNamespaceEFCore2)
-            {
-                return true;
-            }
-
-            return false;
-        }
-
         private static bool ParseComputedDynamicProperties(QueryBinderContext context, IList<DynamicPathSegment> dynamicPathSegments, bool isSelectedAll,
             out IList<string> computedProperties)
         {

test/Microsoft.AspNetCore.OData.E2E.Tests/Microsoft.AspNetCore.OData.E2E.Tests.csproj

@@ -37,6 +37,7 @@
     <PackageReference Include="Microsoft.EntityFrameworkCore.InMemory" Version="6.0.8" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="6.0.8" />
     <PackageReference Include="Microsoft.EntityFrameworkCore.Proxies" Version="6.0.8" />
+    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="6.0.8" />
   </ItemGroup>
 
   <ItemGroup>

test/Microsoft.AspNetCore.OData.E2E.Tests/Regressions/RegressionsController.cs

@@ -0,0 +1,96 @@
+//-----------------------------------------------------------------------------
+// <copyright file="RegressionsController.cs" company=".NET Foundation">
+//      Copyright (c) .NET Foundation and Contributors. All rights reserved.
+//      See License.txt in the project root for license information.
+// </copyright>
+//------------------------------------------------------------------------------
+
+using System.Linq;
+using Microsoft.AspNetCore.Mvc;
+using Microsoft.AspNetCore.OData.Query;
+using Microsoft.EntityFrameworkCore;
+
+namespace Microsoft.AspNetCore.OData.E2E.Tests.Regressions
+{
+    public class UsersController : Controller
+    {
+        private readonly RegressionsDbContext _dbContext;
+
+        public UsersController(RegressionsDbContext dbContext)
+        {
+            dbContext.Database.EnsureCreated();
+            _dbContext = dbContext;
+            if (!_dbContext.Users.Any())
+            {
+                _dbContext.DataFiles.Add(new DataFile
+                {
+                    FileId = 1,
+                    FileName = "76x473626.pdf"
+                });
+
+                DataFile dataFile2 = new DataFile
+                {
+                    FileId = 2,
+                    FileName = "uyr65euit5.pdf"
+                };
+                _dbContext.DataFiles.Add(dataFile2);
+
+                _dbContext.DataFiles.Add(new DataFile
+                {
+                    FileId = 3,
+                    FileName = "hj7x87643.pdf"
+                });
+
+                _dbContext.Users.Add(new User
+                {
+                    UserId = 1,
+                    Name = "Alex",
+                    Age = 35,
+                    DataFileRef = null,
+                    Files = null
+                });
+
+                _dbContext.Users.Add(new User
+                {
+                    UserId = 2,
+                    Name = "Amanda",
+                    Age = 29,
+                    DataFileRef = 2,
+                    Files = dataFile2
+                });
+
+                _dbContext.Users.Add(new User
+                {
+                    UserId = 3,
+                    Name = "Lara",
+                    Age = 25,
+                    DataFileRef = null,
+                    Files = null
+                });
+
+                _dbContext.SaveChanges();
+            }
+        }
+
+        [HttpGet]
+        [EnableQuery]
+        public IQueryable<User> Get()
+        {
+            IQueryable<User> data = _dbContext.Users.AsQueryable();
+            return data;
+        }
+
+        [HttpGet]
+        [EnableQuery]
+        public IActionResult Get(int key)
+        {
+            User data = _dbContext.Users.Include(c => c.Files).FirstOrDefault(c => c.UserId == key);
+            if (data == null)
+            {
+                return NotFound();
+            }
+
+            return Ok(data);
+        }
+    }
+}

test/Microsoft.AspNetCore.OData.E2E.Tests/Regressions/RegressionsDataModel.cs

@@ -0,0 +1,39 @@
+//-----------------------------------------------------------------------------
+// <copyright file="RegressionsDataModel.cs" company=".NET Foundation">
+//      Copyright (c) .NET Foundation and Contributors. All rights reserved.
+//      See License.txt in the project root for license information.
+// </copyright>
+//------------------------------------------------------------------------------
+
+using System.ComponentModel.DataAnnotations.Schema;
+using System.ComponentModel.DataAnnotations;
+
+namespace Microsoft.AspNetCore.OData.E2E.Tests.Regressions
+{
+    public class User
+    {
+        [Key]
+        public int UserId { get; set; }
+
+        [Required]
+        public string Name { get; set; }
+
+        [Required]
+        public int Age { get; set; }
+
+        //Navigations
+        [ForeignKey("Files")]
+        public int? DataFileRef { get; set; }
+
+        public virtual DataFile Files { get; set; }
+    }
+
+    public class DataFile
+    {
+        [Key]
+        public int FileId { get; set; }
+
+        [Required]
+        public string FileName { get; set; }
+    }
+}

test/Microsoft.AspNetCore.OData.E2E.Tests/Regressions/RegressionsDbContext.cs

@@ -0,0 +1,23 @@
+//-----------------------------------------------------------------------------
+// <copyright file="RegressionsDbContext.cs" company=".NET Foundation">
+//      Copyright (c) .NET Foundation and Contributors. All rights reserved.
+//      See License.txt in the project root for license information.
+// </copyright>
+//------------------------------------------------------------------------------
+
+using Microsoft.EntityFrameworkCore;
+
+namespace Microsoft.AspNetCore.OData.E2E.Tests.Regressions
+{
+    public class RegressionsDbContext : DbContext
+    {
+        public RegressionsDbContext(DbContextOptions<RegressionsDbContext> options)
+            : base(options)
+        {
+        }
+
+        public DbSet<User> Users { get; set; }
+
+        public DbSet<DataFile> DataFiles { get; set; }
+    }
+}