reg/tests: Test for integer overflow.

programs/reg/tests/reg.c

@@ -287,6 +287,9 @@ static void test_add(void)
     run_reg_exe("reg add HKCU\\" KEY_BASE " /t REG_DWORD /v dword10 /f /d -0x1", &r);
     todo_wine ok(r == REG_EXIT_FAILURE || broken(r == REG_EXIT_SUCCESS /* WinXP */), "got exit code %u\n", r);
 
+    run_reg_exe("reg add HKCU\\" KEY_BASE " /v dword8 /t REG_dword /d 0x01ffffffff /f", &r);
+    todo_wine ok(r == REG_EXIT_FAILURE || broken(r == REG_EXIT_SUCCESS /* WinXP */), "got exit code %d\n", r);
+
     /* REG_DWORD_LITTLE_ENDIAN */
     run_reg_exe("reg add HKCU\\" KEY_BASE " /v DWORD_LE /t REG_DWORD_LITTLE_ENDIAN /d 456 /f", &r);
     ok(r == REG_EXIT_SUCCESS, "got exit code %d, expected 0\n", r);