Bug 490961

SUMMARY

The command line arguments set via `Rf_initialize_R` and `R_set_command_line_arguments` are incorrect.

The first argument must be the name of the program by which R was invoked.

R assumes that the previous is true, and so it skips the first command line argument.

for Unix, in `Rf_initialize_R`:
https://github.com/wch/r-source/blob/f4de6dfdeb1d8b100d6a70c259c80a20508a4309/src/unix/system.c#L407

for Windows, in `cmdlineoptions`:
https://github.com/wch/r-source/blob/589b76ba28bb97e9d628f6e4ae1735c4e2660b3f/src/gnuwin32/system.c#L1180

for all, in `R_common_command_line`:
https://github.com/wch/r-source/blob/f4de6dfdeb1d8b100d6a70c259c80a20508a4309/src/main/CommandLineArgs.c#L103

I would suggest something more like:

```
	int argc = 4;
	char* argv[4] = { qstrdup ("rkward"), qstrdup ("--slave"), qstrdup ("--no-save"), qstrdup ("--no-restore") };
```

But I have one more suggestion.

I think you should not be using option `--slave`. In interactive use, this turns off printing the prompt when waiting for input and turns off printing a continuation prompt for code that spans multiple lines. That doesn't seem like what you want.

Instead, you should replace it with `--quiet` (or `--silent` or `-q`, but I prefer `--quiet`). When combined with `--no-save`, you end up with the same R settings except `R_NoEcho` is `FALSE`, as it should be:

```
	int argc = 4;
	char* argv[4] = { qstrdup ("rkward"), qstrdup ("--quiet"), qstrdup ("--no-save"), qstrdup ("--no-restore") };
```

OBSERVED RESULT

```R
> commandArgs()
[1] "--slave"
[2] "--no-save"
[3] "--no-restore"
```

EXPECTED RESULT

```R
> commandArgs()
[1] "rkward"
[2] "--quiet"
[3] "--no-save"
[4] "--no-restore"
```