Regression spec for #2967.

Author: headius

spec/regression/GH-2957_nonblock_syswrite_zero_bytes_should_not_eagain_spec.rb

@@ -0,0 +1,14 @@
+require 'socket'
+require 'io/nonblock'
+
+describe 'Writing zero bytes to a nonblocking socket' do
+  it 'returns 0 bytes and does not raise EAGAIN' do
+    begin
+      s = TCPSocket.new('google.com', 80)
+      s.nonblock
+      expect(s.syswrite('')).to eq 0
+    ensure
+      s.close
+    end
+  end
+end