Issue #15895: my analysis was slightly off. The FILE pointer is only leaked when set_main_loader() fails for a pyc file with closeit=0. In the success case run_pyc_file() does its own cleanup of the fp. I've changed the code to use another FILE ptr for pyc files and moved the fclose() to PyRun_SimpleFileExFlags() to make it more obvious what's happening.

#include "Python.h"

#ifndef PLATFORM
#define PLATFORM "unknown"
#endif

const char *
Py_GetPlatform(void)
{
	return PLATFORM;
}