net: `_connectionKey` given wrong value for large port

[trevnorris]

• Version: v0.12+
• Platform: all
• Subsystem: net, affects child_process

Reproduce with:

$ node -e "var s = require('net').createServer().listen(-1 >>> 0); console.log(s._connectionKey, s.address().port)"

Output:

6::::4294967295 65535

Expected output:

6::::65535 65535

Conversation with @indutny:

<trevnorris> indutny: does ._connectionKey do anything?
<indutny> yep
<indutny> child_process.js
<indutny> actually, internal/child_process.js
<indutny> it is used for sharing servers
<trevnorris> okay. well guess it should get fixed then.
<trevnorris> e.g.: var s = net.createServer().listen(-1 >>> 0); s._connectionKey == '6::::4294967295'; s.address().port == 65535
<indutny> mmm
<indutny> yeah
<indutny> this is bad

Haven't gotten around to a fix, so making this up for grabs.

[cjihrig]

We should be able to use s.address().address and s.address().port to build the connection key, right?

[dirceu]

Actually we validate the port number if we do listen({ port: PORT }), but we don't validate if we use listen(PORT). I created a PR (#5732) to make sure we validate in all cases. Makes sense?