Extra comma when citing source without author in footnote with author-in-text style

[cgm616]

Explain the problem.
When citing a source without an author in Chicago style using author-in-text mode inside a footnote, pandoc inserts an extra comma and space before the citation. This sort of citation is extremely useful since Chicago style does not call for parentheses when using citations in discursive footnotes.

test.md:

---
csl: http://www.zotero.org/styles/chicago-fullnote-bibliography
references:
- id: CurtissStrong1809
  citation-key: CurtissStrong1809
  container-title: Day
  issued:
    - year: 1809
      month: 6
      day: 1
  page: '51'
  title: Curtiss v. Strong
  type: legal_case
  volume: '4'
reference-section-title: "Bibliography"
---

# Body

This is what a normal citation should look like.[@CurtissStrong1809]
Now, we'll cite it inside a footnote.^[For instance, see @CurtissStrong1809 [p. 52].]

Output of pandoc --citeproc test.md -o test.pdf:

[snip]
Footnote 1: Curtiss v. Strong, 4 Day 51 (1809).
Footnote 2: For instance, see , Curtiss v. Strong, 4 Day at 52.

Expected output:

[snip]
Footnote 1: Curtiss v. Strong, 4 Day 51 (1809).
Footnote 2: For instance, see Curtiss v. Strong, 4 Day at 52.

This seems to be because of the way that pandoc uses citeproc to simulate author-in-text citations, but I don't know Haskell and couldn't really figure it out. It is not limited to legal cases.

Pandoc version?
I am using pandoc version 2.16.2 on macOS Monterey 12.1.

> pandoc --version
pandoc 2.16.2
Compiled with pandoc-types 1.22.1, texmath 0.12.3.2, skylighting 0.12.1,
citeproc 0.6, ipynb 0.1.0.2
User data directory: /Users/cgm616/.local/share/pandoc
Copyright (C) 2006-2021 John MacFarlane. Web:  https://pandoc.org
This is free software; see the source for copying conditions. There is no
warranty, not even for merchantability or fitness for a particular purpose.

[jgm]

Since this is a footnote style, you can just do

Now, we'll cite it inside a footnote [For instance, see @CurtissStrong1809, p. 52].

and pandoc will put it in a note for you. That's the recommended way of writing citations (it makes it possible to switch easily to a non-footnote style).

[jgm]

This issue looks like a dup of #7761 which is already fixed in master!
You can try a nightly.

[cgm616]

I'll try a nightly. The reason I'm not using the preferred method is because I can't seem to get it to work with multiple references in the same footnote.

Now, we'll cite it inside a footnote.[For instance, see @CurtissStrong1809, p. 52 and @austinHowThingsWords1965.]

The above only renders How to Do Things with Words, The William James Lectures: 1955 (Oxford University Press, 1965). in the footnote and sometimes results in strange artifacts showing up in the text.

[jgm]

If you replace "and" with a semicolon, it will work (though you won't get the word "and").