Index: apitests/kernel32/CMakeLists.txt
===================================================================
--- apitests/kernel32/CMakeLists.txt	(revision 69255)
+++ apitests/kernel32/CMakeLists.txt	(working copy)
@@ -13,7 +13,8 @@
     SetUnhandledExceptionFilter.c
     TerminateProcess.c
     TunnelCache.c
-    testlist.c)
+    testlist.c
+    Mailslot.c)
 
 add_executable(kernel32_apitest ${SOURCE})
 target_link_libraries(kernel32_apitest wine ${PSEH_LIB})
Index: apitests/kernel32/Mailslot.c
===================================================================
--- apitests/kernel32/Mailslot.c	(revision 0)
+++ apitests/kernel32/Mailslot.c	(working copy)
@@ -0,0 +1,78 @@
+/*
+ * PROJECT:         ReactOS api tests
+ * LICENSE:         GNU GPLv2 only as published by the Free Software Foundation
+ * PURPOSE:         Test for mailslot (CORE-10188)
+ * PROGRAMMER:      Nikita Pechenkin (n.pechenkin@mail.ru)
+ */
+
+#include <apitest.h>
+
+#define WIN32_NO_STATUS
+#include <stdio.h>
+
+#define LMS TEXT("\\\\.\\mailslot\\rostest_slot")
+#define MSG (0x50DA)
+
+static DWORD dInMsg  = MSG;
+static DWORD dOutMsg = 0x0;
+
+DWORD
+WINAPI
+MailSlotWriter(
+        LPVOID lpParam)
+{
+    DWORD cbWritten;
+    HANDLE hMailslot;
+
+    hMailslot = CreateFile(LMS, GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE,
+            NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
+    ok(hMailslot != INVALID_HANDLE_VALUE, "CreateFile failed, results might not be accurate\n");
+    if (hMailslot != INVALID_HANDLE_VALUE)
+    {
+        Sleep(1000);
+        ok(WriteFile(hMailslot, &dInMsg, sizeof(dInMsg), &cbWritten, (LPOVERLAPPED) NULL), "Slot write failed\n");
+        CloseHandle(hMailslot);
+    }
+    return 0;
+}
+
+DWORD
+WINAPI
+MailSlotReader(
+        LPVOID lpParam)
+{
+    HANDLE hMailslotClient;
+    DWORD cbRead;
+
+    hMailslotClient = CreateMailslot(LMS, 0L, MAILSLOT_WAIT_FOREVER, (LPSECURITY_ATTRIBUTES) NULL);
+    ok(hMailslotClient != INVALID_HANDLE_VALUE, "CreateMailslot failed\n");
+    if (hMailslotClient != INVALID_HANDLE_VALUE)
+    {
+        ok(ReadFile(hMailslotClient, &dOutMsg, sizeof(dOutMsg), &cbRead, NULL), "Slot read failed\n");
+        CloseHandle(hMailslotClient);
+    }
+    return 0;
+}
+
+void
+StartTestCORE10188()
+{
+    HANDLE  hThreadArray[2] =
+    {
+        CreateThread(NULL,0, MailSlotReader, NULL, 0, NULL),
+        CreateThread(NULL,0, MailSlotWriter, NULL, 0, NULL)
+    };
+    ok(hThreadArray[0]!=INVALID_HANDLE_VALUE && hThreadArray[1]!=INVALID_HANDLE_VALUE, "CreateThread failed\n");
+    if (hThreadArray[0]!=INVALID_HANDLE_VALUE && hThreadArray[1]!=INVALID_HANDLE_VALUE)
+    {
+        WaitForMultipleObjects(2, hThreadArray, TRUE, INFINITE);
+        CloseHandle(hThreadArray[0]);
+        CloseHandle(hThreadArray[1]);
+    }
+    ok(dInMsg==dOutMsg, "Transfer data failed\n");
+}
+
+START_TEST(Mailslot)
+{
+    StartTestCORE10188();
+}
Index: apitests/kernel32/testlist.c
===================================================================
--- apitests/kernel32/testlist.c	(revision 69255)
+++ apitests/kernel32/testlist.c	(working copy)
@@ -16,6 +16,7 @@
 extern void func_SetUnhandledExceptionFilter(void);
 extern void func_TerminateProcess(void);
 extern void func_TunnelCache(void);
+extern void func_Mailslot(void);
 
 const struct test winetest_testlist[] =
 {
@@ -32,6 +33,7 @@
     { "SetUnhandledExceptionFilter", func_SetUnhandledExceptionFilter },
     { "TerminateProcess",            func_TerminateProcess },
     { "TunnelCache",                 func_TunnelCache },
+    { "Mailslot",                    func_Mailslot },
     { 0, 0 }
 };