roundtrippping content causes definition to disappear

[ChristianMurphy]

Initial checklist

• I read the support docs
• I read the contributing guide
• I agree to follow the code of conduct
• I searched issues and couldn’t find anything (or linked relevant results below)

Affected packages and versions

1.2.4

Link to runnable example

https://stackblitz.com/edit/node-st1b3g?file=index.js

Steps to reproduce

Run

import { remark as remarFactory } from 'remark';
import { visit } from 'unist-util-visit';

const remark = remarFactory();

// clean extra attributes that make it hard to see issue
function scrubber(tree) {
  visit(tree, function (node) {
    node.value = undefined;
    node.position = undefined;
    node.spread = undefined;
    node.lang = undefined;
    node.identifier = undefined;
    node.label = undefined;
    node.title = undefined;
    node.url = undefined;
  });
}

const content = `[a]: `;

const originalAst = remark.parse(content);
const newContent = remark.stringify(originalAst);
const newAst = remark.parse(newContent);

scrubber(originalAst);
scrubber(newAst);

console.log(JSON.stringify(originalAst, null, 4));
console.log(JSON.stringify(newAst, null, 4));

result is:

{
    "type": "root",
    "children": [
        {
            "type": "definition"
        }
    ]
}

then

{
    "type": "root",
    "children": [
        {
            "type": "paragraph",
            "children": [
                {
                    "type": "text"
                }
            ]
        }
    ]
}

and the output text is

[a]: 

Expected behavior

definition content is preserved

Actual behavior

definition content disapepars

Runtime

Node v16

Package manager

npm v7

OS

Linux

Build and bundle tools

No response

[ChristianMurphy]

also happens with

[a]

[a]: 

[ChristianMurphy]

https://spec.commonmark.org/dingus/?text=%5Ba%5D%0A%0A%5Ba%5D%3A%20%26%23xc%3B%0A

[wooorm]

released!