Do not execute `commandLineCombined` when we have only one command parameter

[windowsair]

First of all, thank you for this project, it's the most convenient C/C++ library I've seen so far!

This question is out of my personal preference.

Sometimes I like to use a cmd like this:

const char* command_line[] = {
"foo \"bar\" \"\\\\\"\" ",
NULL
};

And this is the current msvc implementation in the project:

  // Combine commandLine together into a single string
  len = 0;
  for (i = 0; commandLine[i]; i++) {
    // For the ' ' and two '"' between items and trailing '\0'
    len += 3;

    for (j = 0; '\0' != commandLine[i][j]; j++) {
      switch (commandLine[i][j]) {
      default:
        break;
      case '\\':
        if (commandLine[i][j + 1] == '"') {
          len++;
        }

        break;
      case '"':
        len++;
        break;
      }
      len++;
    }
  }

Well, I didn't look closely at the code, but when I had only one command, I observed the wrong escape.

As mentioned above, this is likely to be a complex command line if there is only one command. It is better to follow the user's input and just take the command line without modifying it.

What do you think about this? Thanks!

[windowsair]

But it doesn't look like it meets the specification.... I'm not sure that's a good idea.

[sheredom]

Yeah I'm torn about this - it makes the library behave differently depending on if you have a single arg or not. Seems bad to me on first instincts!

[windowsair]

Yes, this approach may not be good. Perhaps we should focus on issues like #59.

[takase1121]

The way libuv (and by extension Node.js) fixes this is by adding another option windowsVerbatimArgument which will simply concatenate the arguments without escaping.

https://nodejs.org/api/child_process.html#child_processexecfilefile-args-options-callback