doc: process.umask doc unclear

[jsumners]

• Subsystem: doc

https://github.com/nodejs/node/blob/199ad1d73f81c1d568232df418090e9ce3c4a7fb/doc/api/process.md#processumaskmask

The documentation for process.umask reads:

The process.umask() method sets or returns the Node.js process's file mode creation mask. Child processes inherit the mask from the parent process. The old mask is return if the mask argument is given, otherwise returns the current mask.

I have emphasized the last sentence since that is the one that doesn't make any sense. Is it saying var oldmask = process.umask() or var oldmask = process.umask(0)?

[bnoordhuis]

Both, except the no-arg version doesn't change the umask so the returned value is still the active umask after the call returns.

[jsumners]

How about:

Invoked without an argument, the current mask is returned, otherwise the umask is set to the argument value and the previous mask is returned.

[bnoordhuis]

Sounds good.