fix listenany to return correct port number for porthint of 0

base/distributed/cluster.jl

@@ -153,15 +153,8 @@ function start_worker(out::IO, cookie::AbstractString)
     init_worker(cookie)
     interface = IPv4(LPROC.bind_addr)
     if LPROC.bind_port == 0
-        addr = Base.InetAddr(interface, 0)
-        sock = Base.TCPServer()
-        if bind(sock, addr) && Base.trylisten(sock) == 0
-            _addr, port = Base._sockname(sock, true)
-            LPROC.bind_port = port
-        else
-            close(sock)
-            error("no ports available")
-        end
+        (port, sock) = listenany(interface, UInt16(0))
+        LPROC.bind_port = port
     else
         sock = listen(interface, LPROC.bind_port)
     end

base/socket.jl

@@ -826,6 +826,10 @@ function listenany(host::IPAddr, default_port)
     while true
         sock = TCPServer()
         if bind(sock, addr) && trylisten(sock) == 0
+            if default_port == 0
+                _addr, port = _sockname(sock, true)
+                return (port, sock)
+            end
             return (addr.port, sock)
         end
         close(sock)

test/socket.jl

@@ -69,27 +69,29 @@ end
 # test show() function for UDPSocket()
 @test repr(UDPSocket()) == "UDPSocket(init)"
 
-port = Channel(1)
 defaultport = rand(2000:4000)
-tsk = @async begin
-    p, s = listenany(defaultport)
-    put!(port, p)
-    sock = accept(s)
-    # test write call
-    write(sock,"Hello World\n")
-
-    # test "locked" println to a socket
-    @sync begin
-        for i in 1:100
-            @async println(sock, "a", 1)
+for testport in [0, defaultport]
+    port = Channel(1)
+    tsk = @async begin
+        p, s = listenany(testport)
+        put!(port, p)
+        sock = accept(s)
+        # test write call
+        write(sock,"Hello World\n")
+
+        # test "locked" println to a socket
+        @sync begin
+            for i in 1:100
+                @async println(sock, "a", 1)
+            end
         end
+        close(s)
+        close(sock)
     end
-    close(s)
-    close(sock)
+    wait(port)
+    @test readstring(connect(fetch(port))) == "Hello World\n" * ("a1\n"^100)
+    wait(tsk)
 end
-wait(port)
-@test readstring(connect(fetch(port))) == "Hello World\n" * ("a1\n"^100)
-wait(tsk)
 
 mktempdir() do tmpdir
     socketname = is_windows() ? ("\\\\.\\pipe\\uv-test-" * randstring(6)) : joinpath(tmpdir, "socket")