fix(pdf): place bottom caption in longtable foot for computational tables

news/changelog-1.10.md

@@ -29,6 +29,7 @@ All changes included in 1.10:
 - ([#13588](https://github.com/quarto-dev/quarto-cli/issues/13588)): Fix Lua error when rendering PDF with `reference-location: margin` and a footnote alongside a figure with `fig-cap`. (author: @mcanouil)
 - ([#14553](https://github.com/quarto-dev/quarto-cli/issues/14553)): Fix font fallbacks (`mainfontfallback`, `sansfontfallback`, `monofontfallback`) crashing LuaLaTeX on TeX Live 2026 (luaotfload v3.29+) instead of filling in missing glyphs. Bare fallback names (e.g. `"DejaVu Sans"`) are now automatically colon-terminated as luaotfload requires; names that already carry a terminator or feature options (e.g. `"FreeSans:"`, `"Noto:mode=harf"`) are left untouched. A clear, actionable error is also reported if a fallback crash is still detected.
 - ([#14553](https://github.com/quarto-dev/quarto-cli/issues/14553), [#14558](https://github.com/quarto-dev/quarto-cli/issues/14558)): Fix PDF render failing instead of auto-installing a missing font referenced by `monofontfallback` (and other `mainfont`/`sansfont`/`monofont` fallbacks).
+- ([#14575](https://github.com/quarto-dev/quarto-cli/issues/14575)): Fix caption being placed inside the table body instead of below it for cross-referenceable computational (knitr/Jupyter) tables with `tbl-cap-location: bottom`.
 
 ### `typst`
 

src/resources/filters/customnodes/floatreftarget.lua

@@ -505,10 +505,29 @@ end, function(float)
               end
               return result
             else
+              -- For a bottom caption, place the caption inside the longtable
+              -- foot (immediately before \endlastfoot) so it renders below the
+              -- table, matching Pandoc's native longtable output. Without this,
+              -- the caption lands after the data rows but inside the body. See #14575.
+              -- Tables without a foot (e.g. kable(longtable=TRUE)) fall through
+              -- to the behavior below.
+              local foot_pos = cap_loc ~= "top" and content:find("\\endlastfoot", 1, true)
+              if foot_pos then
+                return pandoc.Blocks({
+                  pandoc.RawBlock("latex", longtable_preamble),
+                  pandoc.RawBlock("latex", start),
+                  pandoc.RawBlock("latex", content:sub(1, foot_pos - 1)),
+                  latex_caption,
+                  pandoc.RawInline("latex", "\\tabularnewline"),
+                  pandoc.RawBlock("latex", content:sub(foot_pos)),
+                  pandoc.RawBlock("latex", "\\end{longtable}"),
+                  pandoc.RawBlock("latex", longtable_postamble),
+                })
+              end
               local result = pandoc.Blocks({latex_caption, pandoc.RawInline("latex", "\\tabularnewline")})
               -- if cap_loc is top, insert content on bottom
               if cap_loc == "top" then
-                result:insert(pandoc.RawBlock("latex", content))        
+                result:insert(pandoc.RawBlock("latex", content))
               else
                 result:insert(1, pandoc.RawBlock("latex", content))
               end

tests/docs/smoke-all/2026/06/30/14575-knitr.qmd

@@ -0,0 +1,43 @@
+---
+# Issue #14575 — knitr engine cases. See the body below for details.
+format: pdf
+tbl-cap-location: bottom
+keep-tex: true
+_quarto:
+  tests:
+    pdf:
+      noErrors: default
+      ensureLatexFileRegexMatches:
+        -
+          - '\\end\{document\}'
+          - '\\caption\{[\s\S]{0,60}CAP7 caption[\s\S]{0,60}\\tabularnewline\s*\\endlastfoot'
+          - '\\caption\{[\s\S]{0,60}CAP8 caption[\s\S]{0,60}\\tabularnewline\s*\\endlastfoot'
+---
+
+With `tbl-cap-location: bottom`, a knitr `kable()` table that Quarto wraps in
+`.cell-output-display` must place its bottom caption in the longtable foot —
+`\caption{...}\tabularnewline` immediately before `\endlastfoot` — not inside
+the table body. Both assertions above check that placement.
+
+Case 7 is the reported bug (cross-referenced kable with a label); it passes
+only after the fix. Case 8 (kable with a caption but no label) already
+rendered correctly and acts as a regression guard.
+
+The `kable(longtable = TRUE, caption = ...)` variant is a different shape —
+its longtable has no `\endlastfoot`, so the caption is orphaned — and is
+tracked separately, out of scope here.
+
+# Case 7: knitr kable with label (reported bug)
+
+```{r}
+#| label: tbl-c7
+#| tbl-cap: "CAP7 caption"
+knitr::kable(head(cars, 3))
+```
+
+# Case 8: knitr kable with tbl-cap, no label (guard)
+
+```{r}
+#| tbl-cap: "CAP8 caption"
+knitr::kable(head(cars, 3))
+```

tests/docs/smoke-all/2026/06/30/14575.qmd

@@ -0,0 +1,84 @@
+---
+# Issue #14575 — markdown-only cases (CI-safe, no engine needed).
+# See the body below for what each case exercises.
+format: pdf
+tbl-cap-location: bottom
+keep-tex: true
+_quarto:
+  tests:
+    pdf:
+      noErrors: default
+      ensureLatexFileRegexMatches:
+        -
+          - '\\end\{document\}'
+          - '\\caption\{[\s\S]{0,60}CAP1 caption[\s\S]{0,60}\\tabularnewline\s*\\endlastfoot'
+          - '\\caption\{[\s\S]{0,60}CAP2 caption[\s\S]{0,60}\\tabularnewline\s*\\endlastfoot'
+          - '\\caption\{[\s\S]{0,60}CAP3 caption[\s\S]{0,60}\\tabularnewline\s*\\endlastfoot'
+          - '\\caption\{[\s\S]{0,60}CAP4 caption[\s\S]{0,60}\\tabularnewline\s*\\endlastfoot'
+          - '\\caption\{[\s\S]{0,60}CAP5 caption[\s\S]{0,60}\\tabularnewline\s*\\endlastfoot'
+          - '\\caption\{[\s\S]{0,60}CAP6 caption[\s\S]{0,60}\\tabularnewline\s*\\endlastfoot'
+---
+
+With `tbl-cap-location: bottom`, a cross-referenceable table's bottom caption
+must land in the longtable foot — `\caption{...}\tabularnewline` immediately
+before `\endlastfoot` — not after the data rows inside the table body. Each
+`CAPn caption` assertion above checks that placement for one input shape.
+
+Cases 1–4 already rendered correctly before the fix and act as regression
+guards. Cases 5–6 wrap the table in a `.cell-output-display` Div (the shape
+Quarto produces for knitr/Jupyter output); these triggered the bug and pass
+only after the fix.
+
+# Case 1: markdown table, caption syntax, no id
+
+| speed| dist|
+|-----:|----:|
+|     4|    2|
+
+: CAP1 caption
+
+# Case 2: markdown table, caption syntax, with id
+
+| speed| dist|
+|-----:|----:|
+|     4|    2|
+
+: CAP2 caption {#tbl-c2}
+
+# Case 3: div float, bare table, trailing caption paragraph
+
+::: {#tbl-c3}
+| speed| dist|
+|-----:|----:|
+|     4|    2|
+
+CAP3 caption
+:::
+
+# Case 4: div float, tbl-cap attribute, bare table
+
+::: {#tbl-c4 tbl-cap='CAP4 caption'}
+| speed| dist|
+|-----:|----:|
+|     4|    2|
+:::
+
+# Case 5: div float, tbl-cap attribute, .cell-output-display wrapper
+
+::: {#tbl-c5 tbl-cap='CAP5 caption'}
+::: {.cell-output-display}
+| speed| dist|
+|-----:|----:|
+|     4|    2|
+:::
+:::
+
+# Case 6: .cell + .cell-output-display (mcanouil reprex)
+
+::: {#tbl-c6 .cell tbl-cap='CAP6 caption'}
+::: {.cell-output-display}
+| speed| dist|
+|-----:|----:|
+|     4|    2|
+:::
+:::