Fix test_util_file for VS2013 too, but skip all the tests for anything older than that because the limitations are too inconvenient.

CMakeLists.txt

@@ -21,7 +21,9 @@ endif()
 
 include(CTest)
 
-if (CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME AND BUILD_TESTING)
+if (CMAKE_PROJECT_NAME STREQUAL PROJECT_NAME AND BUILD_TESTING AND
+   (NOT MSVC OR NOT (MSVC_VERSION LESS 1800)) # Tests need at least VS2013
+   )
 add_subdirectory(tests)
 endif()
 

tests/test_util_file.c

@@ -19,6 +19,7 @@
 
 #include "json.h"
 #include "json_util.h"
+#include "snprintf_compat.h"
 
 static void test_read_valid_with_fd(const char *testdir);
 static void test_read_valid_nested_with_fd(const char *testdir);