Sockets.get(peer|sock)name on closed TCPSocket segfaults

[fredrikekre]

Could probably be an error instead?

sock.handle is a null pointer here

julia/stdlib/Sockets/src/Sockets.jl

Line 817 in 5dbf45a

sock.handle, rport, raddress, rfamily)

and here

julia/stdlib/Sockets/src/Sockets.jl

Line 821 in 5dbf45a

sock.handle, rport, raddress, rfamily)

Would peer = isopen(sock) ? getpeername(sock) : nothing be a safe alternative to avoid this segfault (or error if this issue is fixed)?

[vtjnash]

Normally we'd call check_open(sock) somewhere near the top of the function, and let that throw an exception if the state is invalid for access

[cljord]

Hi @vtjnash @fredrikekre

I'm pretty new to contributing to open-source and Julia, but it sounds like the solution is really just adding the check_open(sock) check to the top of the function (I took a look at check_open and it throws an error itself). If I understood that correctly, I'd like to take this issue.

[cljord]

Hi again,
so I added the check_open(sock) to the beginning of the function, but now the tests fail. I've poked around a little and the buildbot always has a:

nested task error: ArgumentError: TCPSocket(RawFD(19) init, 0 bytes waiting) is not initialized

from runtests.jl, starting at line 93.

Sorry for probably adding more work than I solved, but I'm in a bit over my head with this large a codebase and I can't figure it out. My pull request is #41000 for a closer look at the buildbot.