The number of columns is misplaced when the shfmt parses the backquote command with escape symbols.

[tegixia]

• The shell statement is as follows:

#!/bin/bash
demo=3
last=`echo \\$demo`

After parsing,The number of columns of the keyword ‘\$demo’ is misplaced.It's supposed to be 12 to 19, but it's actually 12 to 18.

• shfmt parse tree：

[
    {
        "Pos": {
            "Offset": 27,
            "Line": 3,
            "Col": 7
        },
        "End": {
            "Offset": 31,
            "Line": 3,
            "Col": 11
        },
        "Parts": [
            {
                "Type": "Lit",
                "Pos": {
                    "Offset": 27,
                    "Line": 3,
                    "Col": 7
                },
                "End": {
                    "Offset": 31,
                    "Line": 3,
                    "Col": 11
                },
                "ValuePos": {
                    "Offset": 27,
                    "Line": 3,
                    "Col": 7
                },
                "ValueEnd": {
                    "Offset": 31,
                    "Line": 3,
                    "Col": 11
                },
                "Value": "echo"
            }
        ]
    },
    {
        "Pos": {
            "Offset": 33,
            "Line": 3,
            "Col": 12
        },
        "End": {
            "Offset": 39,
            "Line": 3,
            "Col": 18
        },
        "Parts": [
            {
                "Type": "Lit",
                "Pos": {
                    "Offset": 33,
                    "Line": 3,
                    "Col": 12
                },
                "End": {
                    "Offset": 39,
                    "Line": 3,
                    "Col": 18
                },
                "ValuePos": {
                    "Offset": 33,
                    "Line": 3,
                    "Col": 12
                },
                "ValueEnd": {
                    "Offset": 39,
                    "Line": 3,
                    "Col": 18
                },
                "Value": "\\$demo"
            }
        ]
    }
]

[mvdan]

Thanks. This one was quite tricky to figure out, but I think I have now.