Duplicates the tenant id in a sub query when using ctid in the case o…

src/CoreTests/Partitioning/querying_against_conjoined_partitioning_with_tenant_id_and_subquery.cs

@@ -0,0 +1,58 @@
+using System.Linq;
+using System.Threading.Tasks;
+using Marten;
+using Marten.Testing.Documents;
+using Marten.Testing.Harness;
+using Shouldly;
+using Xunit;
+using Xunit.Abstractions;
+
+namespace CoreTests.Partitioning;
+
+public class querying_against_conjoined_partitioning_with_tenant_id_and_subquery : OneOffConfigurationsContext
+{
+    private readonly ITestOutputHelper _output;
+
+    public querying_against_conjoined_partitioning_with_tenant_id_and_subquery(ITestOutputHelper output)
+    {
+        _output = output;
+    }
+
+    [Fact]
+    public async Task do_not_bleed_tenant_data_because_of_select_queries()
+    {
+        var reds = Target.GenerateRandomData(100).ToArray();
+        var blues = Target.GenerateRandomData(1000).ToArray();
+
+        StoreOptions(opts =>
+        {
+            opts.Policies.AllDocumentsAreMultiTenantedWithPartitioning(x =>
+            {
+                x.ByList()
+                    .AddPartition("red", "red")
+                    .AddPartition("blue", "blue");
+            });
+        });
+
+        await theStore.BulkInsertAsync("red", reds);
+        await theStore.BulkInsertAsync("blue", blues);
+
+        using var session = theStore.LightweightSession("red");
+        session.Logger = new TestOutputMartenLogger(_output);
+
+        var matching = await session.Query<Target>()
+            .Where(x => x.Children.Any(c => c.Number > 8))
+            .OrderBy(x => x.Id)
+            .Select(x => x.Id)
+            .ToListAsync();
+
+        var expected = reds.Where(x => x.Children.Any(c => c.Number > 8))
+            .OrderBy(x => x.Id)
+            .Select(x => x.Id)
+            .ToList();
+
+        matching.Count.ShouldBe(expected.Count);
+
+        matching.ShouldBe(expected);
+    }
+}

src/Marten/Linq/Members/DocumentQueryableMemberCollection.cs

@@ -6,8 +6,10 @@
 using System.Linq.Expressions;
 using System.Reflection;
 using JasperFx.Core;
+using JasperFx.Core.Reflection;
 using Marten.Linq.Parsing.Operators;
 using Marten.Schema;
+using Marten.Storage;
 using Weasel.Postgresql;
 using Weasel.Postgresql.SqlGeneration;
 
@@ -24,6 +26,8 @@ public DocumentQueryableMemberCollection(IDocumentMapping mapping, StoreOptions
         ElementType = mapping.DocumentType;
     }
 
+    public TenancyStyle TenancyStyle { get; set; } = TenancyStyle.Single;
+
     public string MemberName => string.Empty;
 
     public string JsonPathSegment => "";

src/Marten/Linq/SqlGeneration/Filters/SubQueryFilter.cs

@@ -1,6 +1,7 @@
 #nullable enable
 using Marten.Internal;
 using Marten.Linq.Members;
+using Marten.Storage;
 using Weasel.Postgresql;
 using Weasel.Postgresql.SqlGeneration;
 
@@ -43,6 +44,16 @@ void ISqlFragment.Apply(ICommandBuilder builder)
             builder.Append("NOT(");
         }
 
+        if (builder.TenantId != Tenancy.DefaultTenantId && Member is ChildCollectionMember child)
+        {
+            if (child.Ancestors[0] is DocumentQueryableMemberCollection c && c.TenancyStyle == TenancyStyle.Conjoined)
+            {
+                builder.Append("d.tenant_id = ");
+                builder.AppendParameter(builder.TenantId);
+                builder.Append(" and ");
+            }
+        }
+
         builder.Append("d.ctid in (select ctid from ");
         builder.Append(_exportName!);
         builder.Append(")");

src/Marten/Schema/DocumentMapping.cs

@@ -128,6 +128,8 @@ public DocumentMapping(Type documentType, StoreOptions storeOptions)
 
         StoreOptions.applyPostPolicies(this);
 
+        QueryMembers.TenancyStyle = TenancyStyle;
+
         _schema = new Lazy<DocumentSchema>(() => new DocumentSchema(this));
 
         if (DisablePartitioningIfAny)