From 7ae2b7698e556ebf0493098682c14057155e7ccf Mon Sep 17 00:00:00 2001
From: Michael Nebel <michaelnebel@github.com>
Date: Mon, 19 Jan 2026 13:17:07 +0100
Subject: [PATCH] C#: Relax the condition for when a qualified expression might
 be null.

---
 csharp/ql/lib/semmle/code/csharp/dataflow/Nullness.qll | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/csharp/ql/lib/semmle/code/csharp/dataflow/Nullness.qll b/csharp/ql/lib/semmle/code/csharp/dataflow/Nullness.qll
index 756fd6a4e3a..c7ac34d3d01 100644
--- a/csharp/ql/lib/semmle/code/csharp/dataflow/Nullness.qll
+++ b/csharp/ql/lib/semmle/code/csharp/dataflow/Nullness.qll
@@ -47,7 +47,8 @@ private Expr maybeNullExpr(Expr reason) {
   result =
     any(QualifiableExpr qe |
       qe.isConditional() and
-      qe.getQualifier() = maybeNullExpr(reason)
+      reason = qe.getQualifier() and
+      not qe instanceof AssignableWrite
     )
 }