fix: Renew MkDocs' relpath processor instead of using same instance

pawamoy · pawamoy · commit 4ab180d01964 · 2025-02-03T20:49:26.000+01:00
Issue-mkdocs-3919: mkdocs/mkdocs#3919
diff --git a/src/mkdocstrings/handlers/base.py b/src/mkdocstrings/handlers/base.py
@@ -523,7 +523,9 @@ def _update_env(self, md: Markdown, *, config: Any | None = None) -> None:
 
         # MkDocs adds its own (required) extension that's not part of the config. Propagate it.
         if "relpath" in md.treeprocessors:
-            new_md.treeprocessors.register(md.treeprocessors["relpath"], "relpath", priority=0)
+            relpath = md.treeprocessors["relpath"]
+            new_relpath = type(relpath)(relpath.file, relpath.files, relpath.config)  # type: ignore[attr-defined,call-arg]
+            new_md.treeprocessors.register(new_relpath, "relpath", priority=0)
 
         self._md = new_md
 
