From 8758503918a91dacff4dbc7126eced21787fbfc9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tomasz=20Kami=C5=84ski?= <tkaminsk@redhat.com>
Date: Fri, 27 Feb 2026 19:55:19 +0100
Subject: [PATCH] libstdc++: Add test for -Wnull-deference in istream_iterator
 [PR105580]

	PR libstdc++/105580

libstdc++-v3/ChangeLog:

	* testsuite/24_iterators/istreambuf_iterator/105580.cc: New test.
---
 .../24_iterators/istreambuf_iterator/105580.cc   | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 libstdc++-v3/testsuite/24_iterators/istreambuf_iterator/105580.cc

diff --git a/libstdc++-v3/testsuite/24_iterators/istreambuf_iterator/105580.cc b/libstdc++-v3/testsuite/24_iterators/istreambuf_iterator/105580.cc
new file mode 100644
index 00000000000..85f888b86e7
--- /dev/null
+++ b/libstdc++-v3/testsuite/24_iterators/istreambuf_iterator/105580.cc
@@ -0,0 +1,16 @@
+// { dg-compile }
+// { dg-require-normal-mode "" }
+// { dg-additional-options "-Wnull-dereference" }
+
+#include <string>
+#include <sstream>
+
+int main()
+{
+  std::istringstream in("Hello, world");
+  std::istreambuf_iterator<char> it(in), end;
+  std::string ss(it, end);
+  return 0;
+}
+// { dg-warning ".*null pointer dereference" "" { target *-*-* } 0 }
+