bug: comments are not entirely emitted when comments: 'all' is specified

[michaele-blend]

Bug report

Version 5.19.4

Complete CLI command or minify() options used

/** @returns {terser.MinifyOptions} */
const getTerserOpts = () => ({
  ecma: 2020,
  toplevel: true,

  parse: {},
  mangle: true,
  compress: {
    keep_fargs: false,

    pure_getters: true,
    drop_console: false,
    pure_funcs: [],

    unsafe: true,
    unsafe_arrows: true,
    unsafe_comps: true,
    unsafe_Function: true,
    unsafe_math: true,
    unsafe_symbols: true,
    unsafe_methods: true,
    unsafe_proto: true,

    passes: 10,
  },
  format: {
    comments: 'all',
    wrap_func_args: false,
    wrap_iife: false,
  },
});

const file1 = `
// f1-before

const func = () => 'surprise!';

// f1-after
`
const file2 = `
// f2-before

console.log(func());

// f2-after
`



const terser = require('terser');
terser.minify({ 'file-1.js': file1, 'file-2.js': file2 }, getTerserOpts()).then(console.dir)

terser input

see above

terser output or error

Expected result

when comments: 'all' is specified, I expect to receive all comments: [f1-before, f1-after, f2-before, f2-after].

{
  code: '// f1-before\n// f1-after\n// f2-before\nconsole.log("surprise!");\n// f2-after'
}

(for my use case, I am not too particular about the ordering. but I do care that they are all present)

Actual result
even when comments: 'all' is specified, the f1-after comment is missing

{
  code: '// f1-before\n// f2-before\nconsole.log("surprise!");\n// f2-after'
}