From 4d21384d8f2e8a992abbf96461563e75f7a8b69c Mon Sep 17 00:00:00 2001
From: Timo Kreuzer <timo.kreuzer@reactos.org>
Date: Fri, 11 Jul 2025 10:20:13 +0300
Subject: [PATCH] [COMPILER_APITEST] Add a test for collided unwind

---
 modules/rostests/apitests/compiler/pseh.c | 56 +++++++++++++++++++++++
 1 file changed, 56 insertions(+)

diff --git a/modules/rostests/apitests/compiler/pseh.c b/modules/rostests/apitests/compiler/pseh.c
index ec5f3c72bd3..ecdaaa687ab 100644
--- a/modules/rostests/apitests/compiler/pseh.c
+++ b/modules/rostests/apitests/compiler/pseh.c
@@ -2920,6 +2920,61 @@ static void Test_structs_seh_nested(void)
 
 #endif // _M_IX86
 
+void Test_collided_unwind(void)
+{
+    volatile int Flags = 0;
+    volatile int Count = 0;
+    jmp_buf JumpBuffer;
+    int ret;
+#ifdef _M_IX86
+    unsigned int Registration = __readfsdword(0);
+#endif
+
+    ret = setjmp(JumpBuffer);
+    if (ret == 0)
+    {
+        _SEH2_TRY
+        {
+            _SEH2_TRY
+            {
+                _SEH2_TRY
+                {
+                    Flags |= 1;
+                    *((volatile int*)(LONG_PTR)-1) = 123;
+                }
+                _SEH2_FINALLY
+                {
+                    Count++;
+                    Flags |= 2;
+                    if (Count) // This is to prevent the compiler from optimizing stuff out
+                        longjmp(JumpBuffer, 1);
+                    Flags |= 4;
+                }
+                _SEH2_END;
+            }
+            _SEH2_FINALLY
+            {
+                Count++;
+                Flags |= 8;
+            }
+            _SEH2_END;
+        }
+        _SEH2_EXCEPT(EXCEPTION_EXECUTE_HANDLER)
+        {
+            Flags |= 16;
+        }
+        _SEH2_END;
+    }
+
+    todo_ros ok(Flags == (1 | 2 | 8), "Flags = %x\n", Flags);
+    todo_ros ok(Count == 2, "Count = %d\n", Count);
+#ifdef _M_IX86
+    todo_ros ok(__readfsdword(0) == Registration, "SEH registration corrupted!\n");
+    *(unsigned int*)NtCurrentTeb() = Registration;
+#endif
+
+}
+
 START_TEST(pseh)
 {
 #ifdef _M_IX86
@@ -2928,6 +2983,7 @@ START_TEST(pseh)
     Test_structs_seh_finally();
     Test_structs_seh_nested();
 #endif
+    Test_collided_unwind();
 
 	const struct subtest testsuite[] =
 	{