From d4302ac1a0ea018b16e60165ba3bb2d61f738155 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-Fran=C3=A7ois=20B=2E?=
 <2589111+jfbu@users.noreply.github.com>
Date: Tue, 10 Jun 2025 22:12:47 +0200
Subject: [PATCH] LaTeX: test better if tabularcolumns colspec is
 tabulary-specific

The recently added to sphinx.writer.latex tests in get_table_colspec()
(of Table class) and depart_table() from LaTeXTranslator were giving
false positives on legit specs such as >{\RaggedRight}\X{1}{2} when
testing for presence of the R, L, C, J, or T specifiers.

Refers: #13647.
---
 sphinx/writers/latex.py | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/sphinx/writers/latex.py b/sphinx/writers/latex.py
index 53fa2564f37..95eb35dda36 100644
--- a/sphinx/writers/latex.py
+++ b/sphinx/writers/latex.py
@@ -171,7 +171,9 @@ def get_table_type(self) -> str:
         elif self.has_verbatim:
             return 'tabular'
         elif self.colspec:
-            if any(c in 'LRCJT' for c in self.colspec):
+            assert len(self.colspec) > 2
+            _colspec = re.sub(r'\{.*?\}', '', self.colspec[1:-2])
+            if any(c in 'LRCJT' for c in _colspec):
                 # tabulary would complain "no suitable columns" if none of its
                 # column type were used so we ensure at least one matches.
                 # It is responsability of user to make sure not to use tabulary
@@ -1212,8 +1214,13 @@ def depart_table(self, node: Element) -> None:
                 for _ in self.tables[:-1]:
                     _.has_problematic = True
         else:
+            # We try to catch a tabularcolumns using L, R, J, C, or T.
+            # We can not simply test for presence in the colspec of
+            # one of those letters due to syntax such as >{\RaggedRight}.
             if self.table.colspec:
-                if any(c in self.table.colspec for c in 'LRJCT'):
+                assert len(self.table.colspec) > 2
+                _colspec = re.sub(r'\{.*?\}', '', self.table.colspec[1:-2])
+                if any(c in _colspec for c in 'LRJCT'):
                     logger.warning(
                         __(
                             'colspec %s was given which uses '