From ba455db20068e1206c628910206726a9f0474861 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Nurullah=20T=C3=BCrko=C4=9Flu?= <nurullahtrkglu@gmail.com>
Date: Mon, 19 Oct 2026 13:18:19 +0300
Subject: [PATCH] Fix precompiled queries that are the receiver of an instance
 method call

Fixes #37961
---
 .../Query/Internal/CSharpToLinqTranslator.cs  | 10 ++++++-
 .../PrecompiledQueryRelationalTestBase.cs     | 17 ++++++++++++
 .../Query/PrecompiledQuerySqlServerTest.cs    | 26 +++++++++++++++++++
 3 files changed, 52 insertions(+), 1 deletion(-)

diff --git a/src/EFCore.Design/Query/Internal/CSharpToLinqTranslator.cs b/src/EFCore.Design/Query/Internal/CSharpToLinqTranslator.cs
index c01789ab548..1c488d0ba6b 100644
--- a/src/EFCore.Design/Query/Internal/CSharpToLinqTranslator.cs
+++ b/src/EFCore.Design/Query/Internal/CSharpToLinqTranslator.cs
@@ -102,7 +102,15 @@ public virtual Expression Translate(SyntaxNode node, SemanticModel semanticModel
 
         // Perform data flow analysis to detect all variables flowing into the query (e.g. captured variables)
         _dataFlowsIn.Clear();
-        foreach (var flowsIn in _semanticModel.AnalyzeDataFlow(node).DataFlowsIn)
+        var dataFlow = _semanticModel.AnalyzeDataFlow(node);
+
+        // Analysis fails when the query is the receiver of an instance call (dotnet/roslyn#86099)
+        for (var parent = node.Parent; !dataFlow.Succeeded && parent is ExpressionSyntax; parent = parent.Parent)
+        {
+            dataFlow = _semanticModel.AnalyzeDataFlow(parent);
+        }
+
+        foreach (var flowsIn in dataFlow.DataFlowsIn)
         {
             _dataFlowsIn[flowsIn] = null;
         }
diff --git a/test/EFCore.Relational.Specification.Tests/Query/PrecompiledQueryRelationalTestBase.cs b/test/EFCore.Relational.Specification.Tests/Query/PrecompiledQueryRelationalTestBase.cs
index 79cfe282b3f..4d0d85eb3ed 100644
--- a/test/EFCore.Relational.Specification.Tests/Query/PrecompiledQueryRelationalTestBase.cs
+++ b/test/EFCore.Relational.Specification.Tests/Query/PrecompiledQueryRelationalTestBase.cs
@@ -857,6 +857,23 @@ public virtual Task Terminating_with_cancellation_token()
 CancellationToken token = source.Token;
 Assert.Equal("Blog1", (await context.Blogs.Where(b => b.Id == 8).FirstOrDefaultAsync(token)).Name);
 Assert.Null(await context.Blogs.Where(b => b.Id == 7).FirstOrDefaultAsync(token));
+""");
+
+    [Fact] // #37961
+    public virtual Task Terminating_with_ConfigureAwait()
+        => Test(
+            """
+CancellationTokenSource source = new CancellationTokenSource();
+CancellationToken token = source.Token;
+Assert.Equal("Blog1", (await context.Blogs.Where(b => b.Id == 8).FirstOrDefaultAsync(token).ConfigureAwait(false)).Name);
+""");
+
+    [Fact]
+    public virtual Task Terminating_followed_by_instance_method_call()
+        => Test(
+            """
+var id = 8;
+Assert.Equal("1", context.Blogs.Count(b => b.Id == id).ToString());
 """);
 
     #endregion Reducing terminating operators
diff --git a/test/EFCore.SqlServer.FunctionalTests/Query/PrecompiledQuerySqlServerTest.cs b/test/EFCore.SqlServer.FunctionalTests/Query/PrecompiledQuerySqlServerTest.cs
index 6e2aa5e9bf2..b9180a2f26a 100644
--- a/test/EFCore.SqlServer.FunctionalTests/Query/PrecompiledQuerySqlServerTest.cs
+++ b/test/EFCore.SqlServer.FunctionalTests/Query/PrecompiledQuerySqlServerTest.cs
@@ -1659,6 +1659,32 @@ FROM [Blogs] AS [b]
 """);
     }
 
+    public override async Task Terminating_with_ConfigureAwait()
+    {
+        await base.Terminating_with_ConfigureAwait();
+
+        AssertSql(
+            """
+SELECT TOP(1) [b].[Id], [b].[Name], [b].[Json]
+FROM [Blogs] AS [b]
+WHERE [b].[Id] = 8
+""");
+    }
+
+    public override async Task Terminating_followed_by_instance_method_call()
+    {
+        await base.Terminating_followed_by_instance_method_call();
+
+        AssertSql(
+            """
+@id='8'
+
+SELECT COUNT(*)
+FROM [Blogs] AS [b]
+WHERE [b].[Id] = @id
+""");
+    }
+
     #endregion Reducing terminating operators
 
     #region SQL expression quotability