From f683ad72d4dd8237081973c2a7c6dd4a569c4a77 Mon Sep 17 00:00:00 2001
From: Tim Hoffmann <2836374+timhoffm@users.noreply.github.com>
Date: Sun, 22 May 2022 00:53:29 +0200
Subject: [PATCH] Ensure updated monkey-patching of sphinx-gallery
 EXAMPLE_HEADER

We have copied the EXAMPLE_HEADER and patched it (#22405). This ensures
we are notified if sphinx-gallery changes the EXAMPLE_HEADER. See the
test docstring for more details.
---
 lib/matplotlib/tests/test_doc.py | 34 ++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 lib/matplotlib/tests/test_doc.py

diff --git a/lib/matplotlib/tests/test_doc.py b/lib/matplotlib/tests/test_doc.py
new file mode 100644
index 000000000000..8a4df35179bc
--- /dev/null
+++ b/lib/matplotlib/tests/test_doc.py
@@ -0,0 +1,34 @@
+import pytest
+
+
+def test_sphinx_gallery_example_header():
+    """
+    We have copied EXAMPLE_HEADER and modified it to include meta keywords.
+    This test monitors that the version we have copied is still the same as
+    the EXAMPLE_HEADER in sphinx-gallery. If sphinx-gallery changes its
+    EXAMPLE_HEADER, this test will start to fail. In that case, please update
+    the monkey-patching of EXAMPLE_HEADER in conf.py.
+    """
+    gen_rst = pytest.importorskip('sphinx_gallery.gen_rst')
+
+    EXAMPLE_HEADER = """
+.. DO NOT EDIT.
+.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
+.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
+.. "{0}"
+.. LINE NUMBERS ARE GIVEN BELOW.
+
+.. only:: html
+
+    .. note::
+        :class: sphx-glr-download-link-note
+
+        Click :ref:`here <sphx_glr_download_{1}>`
+        to download the full example code{2}
+
+.. rst-class:: sphx-glr-example-title
+
+.. _sphx_glr_{1}:
+
+"""
+    assert gen_rst.EXAMPLE_HEADER == EXAMPLE_HEADER