From 336c80848543b13af2f3392f1c030df025054621 Mon Sep 17 00:00:00 2001
From: Niels Lohmann <mail@nlohmann.me>
Date: Mon, 5 Oct 2026 13:49:28 +0200
Subject: [PATCH] Skip the #5650 allocator test on MSVC 2015 debug builds

MSVC 2015's debug STL constructs the containers' debug proxies through
the allocator in noexcept constructors, so countdown_allocator's failing
construction crashes test-allocator (SIGSEGV) instead of throwing
std::bad_alloc. Use the guard #5585 uses for the same reason.

Signed-off-by: Niels Lohmann <mail@nlohmann.me>
---
 tests/src/unit-allocator.cpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tests/src/unit-allocator.cpp b/tests/src/unit-allocator.cpp
index bc283ab28..a358e75f9 100644
--- a/tests/src/unit-allocator.cpp
+++ b/tests/src/unit-allocator.cpp
@@ -521,6 +521,10 @@ struct countdown_allocator : std::allocator<T>
 
 TEST_CASE("converting a deeply nested value from another specialization fails cleanly (#5650)")
 {
+    // MSVC 2015's debug STL constructs the containers' debug proxies through
+    // the allocator in noexcept constructors, so a failing construction crashes
+    // the program there instead of throwing std::bad_alloc. Nothing to check.
+#if !(defined(_MSC_VER) && _MSC_VER < 1910 && defined(_ITERATOR_DEBUG_LEVEL) && _ITERATOR_DEBUG_LEVEL > 0)
     using countdown_json = nlohmann::basic_json<std::map,
           std::vector,
           std::string,
@@ -558,6 +562,7 @@ TEST_CASE("converting a deeply nested value from another specialization fails cl
         }
     }
     CHECK(failures > 0);
+#endif
 }
 
 namespace