From 148292df28e778936937e2f15f4b4f18b054b77b Mon Sep 17 00:00:00 2001
From: Even Rouault <even.rouault@spatialys.com>
Date: Sat, 20 Jul 2024 17:45:39 +0200
Subject: [PATCH] Doc: prepare for ReadTheDocs Deprecation: Removal of Sphinx
 context injection at build time

Fixes #4202
---
 docs/source/conf.py | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/docs/source/conf.py b/docs/source/conf.py
index a5814e7323..e2169a1ea8 100644
--- a/docs/source/conf.py
+++ b/docs/source/conf.py
@@ -267,3 +267,14 @@
 
 source_file_root = os.path.join(os.path.dirname(__file__), os.pardir, os.pardir)
 source_file_url_template = "https://github.com/OSGeo/PROJ/blob/master/{}"
+
+# -- Specifics when documentation is built on ReadTheDocs infra
+
+# Cf https://about.readthedocs.com/blog/2024/07/addons-by-default
+
+# Define the canonical URL if you are using a custom domain on Read the Docs
+html_baseurl = os.environ.get("READTHEDOCS_CANONICAL_URL", "")
+
+# Tell Jinja2 templates the build is running on Read the Docs
+if os.environ.get("READTHEDOCS", "") == "True":
+    html_context["READTHEDOCS"] = True