Fix PDF crash with subfigures that each carry an apa-note (#158)

[dhagmann]

Fixes #158.

Problem

Rendering a subfigure layout (::: {#fig-x layout-ncol=2}) where each panel carries an APA-style apa-note crashed apaquarto-pdf. apaquarto-docx and apaquarto-html already handled this; only PDF failed.

There were two stacked problems in apafloatlatex.lua:

1. The reported crash — pandoc.Div({…, float.content, …}): for a single image float.content is one Block, but for a subfigure layout it is a Blocks list, which the Div constructor rejects:

   Block, list of Blocks, or compatible element expected, got table
       while retrieving function argument content
       while retrieving arguments for function Div
   ...apaquarto/apafloatlatex.lua:254: in local 'filter_fn'
   

2. A hidden second bug that the crash masked — processfloat runs on every FloatRefTarget, including each inner subfigure. Because each panel had a note, each got wrapped in its own \begin{figure}…\end{figure}, producing nested figure environments:

   ! LaTeX Error: Not in outer par mode.
   

Fix

In _extensions/apaquarto/apafloatlatex.lua:

• Sub-figures (float.parent_id ~= nil — the same check Quarto uses to identify sub-floats) are no longer wrapped in their own figure environment. They render natively, with their apa-note appended below the image — mirroring the docx/html output.
• The outer container now splices float.content via pandoc.Blocks(...) instead of nesting it, so a Blocks list no longer crashes the Div constructor.

Testing

Added tests/issue-158-subfigure-notes.qmd, a reproducer covering: a single figure + note (control), the exact issue case (subfigures each with a note, no overall caption), the captioned variant, a mixed case (only one panel noted), and a table + note.

Rendered in both documentmode: man and documentmode: jou on TeX Live 2026:

• No crash; valid PDF in both modes.
• All figure notes render (7/7), every cross-reference resolves (no Figure ??), and there are no nested figure environments (max nesting depth = 1).
• Visually confirmed each panel shows its note in both the manuscript and the two-column journal layouts.

Note on layout (possible follow-up)

In PDF the panels stack vertically rather than side-by-side. That is the existing behavior of apaquarto's manual figure-wrapping (note-bearing figures never used minipages) — not a regression from this change, and cross-references resolve. I have a small prototype that makes subfigures render side-by-side (honoring layout-ncol) while keeping the notes, behind an opt-in toggle that defaults to today's vertical layout. Happy to open a separate issue to discuss it if that is of interest.

🤖 Generated with Claude Code

[isaactpetersen]

I confirmed that this pull request fixes the error I was getting when rendering to PDF. Thanks for the fix!