Fix LaTeX builder crash on tables with no body rows

sphinx/builders/latex/transforms.py

@@ -440,10 +440,20 @@ def depart_thead(self, node: nodes.thead) -> None:
         self.unrestrict(node)
 
     def depart_table(self, node: nodes.table) -> None:
-        tbody = next(node.findall(nodes.tbody))
-        for footnote in reversed(self.table_footnotes):
-            fntext = footnotetext('', *footnote.children, ids=footnote['ids'])
-            tbody.insert(0, fntext)
+        tbody = next(node.findall(nodes.tbody), None)
+        if tbody is not None:
+            for footnote in reversed(self.table_footnotes):
+                fntext = footnotetext('', *footnote.children, ids=footnote['ids'])
+                tbody.insert(0, fntext)
+        else:
+            # If there is no tbody (e.g. a table with only header rows),
+            # place any collected footnotes after the table node instead.
+            table_parent = node.parent
+            if table_parent is not None:
+                idx = table_parent.index(node)
+                for i, footnote in enumerate(self.table_footnotes):
+                    fntext = footnotetext('', *footnote.children, ids=footnote['ids'])
+                    table_parent.insert(idx + i + 1, fntext)
 
         self.table_footnotes = []
 

tests/test_builders/test_build_latex.py

@@ -16,6 +16,7 @@
 import docutils
 import pygments
 import pytest
+from docutils import nodes
 
 from sphinx.builders.latex import default_latex_documents
 from sphinx.config import Config
@@ -2097,6 +2098,47 @@ def test_latex_nested_tables(app: SphinxTestApp) -> None:
     assert app.warning.getvalue() == ''
 
 
+def test_latex_table_empty_body() -> None:
+    """Regression test for issue #14271.
+
+    Tables with header rows but no body rows (as produced by e.g.
+    myst_parser from Markdown) should not crash the LaTeX builder
+    with a StopIteration in LaTeXFootnoteVisitor.depart_table.
+    """
+    from docutils.utils import new_document
+
+    from sphinx.builders.latex.transforms import LaTeXFootnoteVisitor
+
+    document = new_document('<test>')
+
+    # Build a table node with thead but no tbody, as myst_parser would
+    # generate from a Markdown table with only a header row.
+    table = nodes.table()
+    tgroup = nodes.tgroup(cols=2)
+    table += tgroup
+    tgroup += nodes.colspec(colwidth=50)
+    tgroup += nodes.colspec(colwidth=50)
+    thead = nodes.thead()
+    tgroup += thead
+    row = nodes.row()
+    thead += row
+    entry1 = nodes.entry()
+    entry1 += nodes.paragraph(text='Header 1')
+    row += entry1
+    entry2 = nodes.entry()
+    entry2 += nodes.paragraph(text='Header 2')
+    row += entry2
+
+    section = nodes.section()
+    section += table
+    document += section
+
+    # This should not raise StopIteration
+    visitor = LaTeXFootnoteVisitor(document, [])
+    visitor.table_footnotes = []
+    table.walkabout(visitor)
+
+
 @pytest.mark.sphinx('latex', testroot='latex-container')
 def test_latex_container(app: SphinxTestApp) -> None:
     app.build(force_all=True)