Empty command `e` inconsistency

[aureliojargas]

$ printf e > e1
$ printf 'e\n' > e2
$ python3 sedparse.py -f e1
[
    {
        "cmd": "e",
        "line": 1
    }
]
$ python3 sedparse.py -f e2
[
    {
        "cmd": "e",
        "line": 1,
        "x": {
            "cmd_txt": {
                "text": [
                    "\n"
                ]
            }
        }
    }
]
$ python3 sedparse.py -e e
[
    {
        "cmd": "e",
        "line": 1
    }
]

When the empty e command is followed by \n (see e2 file in the example), its x.cmd_txt.text property comes with a solo \n. This is confusing and probably wrong. Investigate.

Note that in struct_text_buf, we are removing the trailing \n:

class struct_text_buf(struct):
    # ...
    def __str__(self):
        return "".join(self.text)[:-1]  # remove trailing \n

so using str(x.cmd_txt) instead of accessing x.cmd_txt.text directly, will always produce an empty string in all the previous examples.

>>> import sedparse
>>> prog = []
>>> sedparse.compile_string(prog, 'e')
>>> sedparse.compile_file(prog, 'e1')
>>> sedparse.compile_file(prog, 'e2')
>>> [item.x.cmd_txt.text for item in prog]
[[], [], ['\n']]
>>> [str(item.x.cmd_txt) for item in prog]
['', '', '']
>>>

[aureliojargas]

This extra \n at the end of x.cmd_txt.text is also related to #2.