Fix entity equality contains with ParameterizedCollectionMode.Parameter

src/EFCore.Relational/Query/SqlNullabilityProcessor.cs

@@ -830,6 +830,8 @@ ParameterizedCollectionMode is ParameterizedCollectionMode.Constants
                     ||
                     (ParameterizedCollectionMode is ParameterizedCollectionMode.MultipleParameters
                         && valuesParameter.ShouldBeConstantized);
+                var useParameter = ParameterizedCollectionMode is ParameterizedCollectionMode.Parameter
+                    && !valuesParameter.ShouldBeConstantized;
                 var expandedParameters = _collectionParameterExpansionMap.GetOrAddNew(valuesParameter);
                 var expandedParametersCounter = 0;
                 for (var i = 0; i < values.Count; i++)
@@ -840,9 +842,11 @@ ParameterizedCollectionMode is ParameterizedCollectionMode.Constants
                         continue;
                     }
 
-                    switch (useParameters, useConstants)
+                    switch (useParameters, useConstants, useParameter)
                     {
-                        case (true, false):
+                        case (true, false, false):
+                        // see #36311 for more info
+                        case (false, false, true):
                         {
                             // Create parameter for value if we didn't create it yet,
                             // otherwise reuse it.
@@ -860,7 +864,7 @@ ParameterizedCollectionMode is ParameterizedCollectionMode.Constants
                             break;
                         }
 
-                        case (false, true):
+                        case (false, true, false):
                         {
                             processedValues.Add(_sqlExpressionFactory.Constant(values[i], values[i]?.GetType() ?? typeof(object), sensitive: true, elementTypeMapping));
 
@@ -869,7 +873,7 @@ ParameterizedCollectionMode is ParameterizedCollectionMode.Constants
 
                         default:
                             throw new UnreachableException();
-                    };
+                    }
                 }
             }
             else

test/EFCore.Relational.Specification.Tests/Query/AdHocMiscellaneousQueryRelationalTestBase.cs

@@ -316,6 +316,45 @@ public class TestEntity
         public static readonly IEnumerable<object[]> InlinedRedactingData = [[true, true], [true, false], [false, true], [false, false]];
 
         #endregion
+
+        #region 36311
+
+        [ConditionalTheory]
+        [MemberData(nameof(IsAsyncData))]
+        public async Task Entity_equality_with_Contains_and_Parameter(bool async)
+        {
+            var contextFactory = await InitializeAsync<Context36311>(
+                onConfiguring: o => SetParameterizedCollectionMode(o, ParameterizedCollectionMode.Parameter));
+            using var context = contextFactory.CreateContext();
+
+            List<Context36311.BlogDetails> details = [new Context36311.BlogDetails { Id = 1 }, new Context36311.BlogDetails { Id = 2 }];
+            var query = context.Blogs.Where(b => details.Contains(b.Details));
+
+            var result = async
+                ? await query.ToListAsync()
+                : query.ToList();
+        }
+
+        protected class Context36311(DbContextOptions options) : DbContext(options)
+        {
+            public DbSet<Blog> Blogs { get; set; }
+
+            public class Blog
+            {
+                public int Id { get; set; }
+                public string Name { get; set; }
+
+                public BlogDetails Details { get; set; }
+            }
+
+            public class BlogDetails
+            {
+                public int Id { get; set; }
+                public string Name { get; set; }
+            }
+        }
+
+        #endregion
     }
 }