Fix passing of args intended for node/iojs.

[tawdle]

The recent commit 1430c2b inadvertently broke the ability pass arguments to node/iojs before running mocha -- note that arguments intended for the executable are prepended to args; the previous commit assumes that args[0] will be the executable, but that is only correct if no args intended for the executable have been unshifted onto args.

So, if you try, for instance:

mocha --harmony ...

... you'll get an ENOENT error as spawn tries to execute a file named --harmony.

See #1548 for the origin of this issue.

[danielstjules]

@travisjeffery This seems to work :)

iojs

$ node --version
v1.4.3

$ cat example.js
it('test', function(done) {
  setTimeout(() => done(), 0);
});

// Before PR
$ ./bin/mocha --harmony_arrow_functions example.js
events.js:141
      throw er; // Unhandled 'error' event
            ^
Error: spawn --harmony_arrow_functions ENOENT
    at exports._errnoException (util.js:734:11)
    at Process.ChildProcess._handle.onexit (child_process.js:1022:32)
    at child_process.js:1114:20
    at process._tickCallback (node.js:350:11)
    at Function.Module.runMain (module.js:487:11)
    at startup (node.js:112:16)
    at node.js:863:3

// After PR
$ ./bin/mocha --harmony_arrow_functions example.js

  ․

  1 passing (8ms)

node

$ node --version
v0.12.0
danielstjules:~/git/mocha (master =)
$ cat example.js
it('test', function(done) {
  var fn = function*() {};
  done();
});

// Before PR
$ ./bin/mocha --harmony-generators example.js
events.js:85
      throw er; // Unhandled 'error' event
            ^
Error: spawn --harmony-generators ENOENT
    at exports._errnoException (util.js:746:11)
    at Process.ChildProcess._handle.onexit (child_process.js:1046:32)
    at child_process.js:1137:20
    at process._tickCallback (node.js:355:11)
    at Function.Module.runMain (module.js:503:11)
    at startup (node.js:129:16)
    at node.js:814:3

// After PR
$ ./bin/mocha --harmony-generators example.js

  ․

  1 passing (5ms)

[fengmk2]

+1

1430c2b break all tests with --harmony flags enable...

[fengmk2]

ping @travisjeffery

[danielstjules]

+1 from me :)

[danielstjules]

This is also related to #1583

[danielstjules]

@tawdle Any chance you could add a regression test for this? If not, I can fork this PR and add one.

[davemackintosh]

+1 from me, rolling back.

[danielstjules]

@travisjeffery @boneskull Think we could merge this in and do a quick patch release? I'll see if I can write an acceptance/regression test for this afterward.

[travisjeffery]

Awesome, thanks. Published 2.2.1 with this