Handling EPIPE during write

[milgner]

While trying to send a request, something happens (still investigating the source of the problem, it might be the server dropping the connection), resulting in a EPIPE error.
Would I be correct in assuming that this best be caught in the request writer? If so, I can prepare a PR to that effect.
Of course I'm open to other suggestions :)

(main)> err.backtrace
=> [
    [ 0] "<internal:prelude>:134:in `__write_nonblock'",
    [ 1] "<internal:prelude>:134:in `write_nonblock'",
    [ 2] "/app/vendor/bundle/ruby/2.3.0/gems/http-2.2.2/lib/http/timeout/per_operation.rb:77:in `block in write'",
    [ 3] "/app/vendor/bundle/ruby/2.3.0/gems/http-2.2.2/lib/http/timeout/per_operation.rb:76:in `loop'",
    [ 4] "/app/vendor/bundle/ruby/2.3.0/gems/http-2.2.2/lib/http/timeout/per_operation.rb:76:in `write'",
    [ 5] "/app/vendor/bundle/ruby/2.3.0/gems/http-2.2.2/lib/http/request/writer.rb:99:in `write'",
    [ 6] "/app/vendor/bundle/ruby/2.3.0/gems/http-2.2.2/lib/http/request/writer.rb:87:in `block in send_request'",

[janko]

@milgner Yes, the Errno::EPIPE exception is most likely caused by the server closing the TCP connection. I would think so, because the same exception is raised when using Ruby pipes, where you try to write to the write end of the pipe while after the read end was closed.

read_end, write_end = IO.pipe
read_end.close
write_end.write("content") # Errno::EPIPE: Broken pipe

I think it would be appropriate to raise a HTTP::ConnectionError in this case, and HTTP::Request::Writer looks like an appropriate place to rescue that error.

@milgner It would be great if you could open a PR for this, as it confused me as well recently. I only knew what happened because I'm familiar with the Errno::EPIPE exception from using Ruby pipes.

[janko]

I already opened a PR – #436 😛

[milgner]

Nice! I was afk for the weekend, thank you for the quick patch! 👍