Crash with a request containing a body

[Mike-devs]

I've been spending some time today trying to understand why the simplest Poco application with a web server was crashing. After a lot of trials, I finally pinpointed the source of the problem.

If I send an http request which contains a body (size != 0) to my simple web server, after the timeout I have setup in HTTPServerParams, the application crashes with the following logs:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% Timeout [in file "D:\xxxxxxxxx\ThirdParties\src\poco\Foundation\src\ErrorHandler.cpp", line 38] %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
and the call stack displays this:
Exception thrown at 0x00007FFA4C18051C in tests.exe: Microsoft C++ exception: Poco::TimeoutException at memory location 0x000000B8826FE5B0. Exception thrown at 0x00007FFA4C18051C in tests.exe: Microsoft C++ exception: [rethrow] at memory location 0x0000000000000000. Exception thrown at 0x00007FFA4C18051C in tests.exe: Microsoft C++ exception: Poco::TimeoutException at memory location 0x000000B8826FE5B0. Exception thrown at 0x00007FFA4C18051C in tests.exe: Microsoft C++ exception: Poco::TimeoutException at memory location 0x000000B8826F9F20. Timeout [in file "D:\Dev\Git-CMake-tests\ThirdParties\src\poco\Foundation\src\ErrorHandler.cpp", line 38] A breakpoint instruction (__debugbreak() statement or a similar call) was executed in tests.exe.

I could reproduce that at least on Windows 11 with both VS2019 and VS2022. I tried to compile the same source code on an ARM Linux instance and the Poco::TimeoutException is not thrown in that case (haven't tried yet on an x86 Linux instance but I guess it will not crash).
To fix this, I have to call HTTPServerRequest::stream()::read(). When doing this on Windows web server, then the exception is not thrown.

Have two questions then:

• any idea why the behavior is different on Windows and Linux?
• why do we have to consume the body to avoid the crash? is there a real reason that I can't fathom?

Many thanks!