glog error log was incorrrectly written to unexpected memory

[fanyhawu]

Hi,
I know glog ERROR log message will be written to stderr by default. Most of the time, it work as expected, but occasionally I found it will not be written into stderr and was written into some unexpected memory.
I have checked my source code and then I found there's something that I may did incorrectly:

class NullLogger : public google::base::Logger
{
	virtual void Write(bool, time_t, const char*, int) {
		
	}
	virtual void Flush() {
		
	}
	virtual google::uint32 LogSize() {
		return 0;
	}
};

void init()
{
      ...
      google::SetLogDestination(google::GLOG_INFO, fullpath.c_str());

      // do not generate separate files for warning and error.
	static NullLogger nullLogger;
	google::base::SetLogger(google::GLOG_WARNING,&nullLogger);
	google::base::SetLogger(google::GLOG_ERROR,&nullLogger);
       google::InitGoogleLogging("");
}

note I called google::base::SetLogger() before google::InitGoogleLogging().
If I called google::InitGoogleLogging() first, then call google::base::SetLogger(), just like following code, everything seems work fine, but I can't explain why.

void init()
{
      ...
      google::SetLogDestination(google::GLOG_INFO, fullpath.c_str());
      google::InitGoogleLogging("");
      // do not generate separate files for warning and error.
	static NullLogger nullLogger;
	google::base::SetLogger(google::GLOG_WARNING,&nullLogger);
	google::base::SetLogger(google::GLOG_ERROR,&nullLogger);
       
}

I know for glog some operations should be done before google::InitGoogleLogging(), such as "setting value of FLAGS_log_dir".
I have checked google::InitGoogleLogging() source code, it looks it only defines the g_main_thread_id and marked if it has been initialized. my question is: if I call google::base::SetLogger() before google::InitGoogleLogging(), will there be some issue that you can imagine?

[fanyhawu]

even SetLogger() after init(), still same issue, I'll go to check by myself