Fixed two more bugs with SVG inheritance-diagram links

CHANGES

@@ -16,6 +16,10 @@ Features added
 Bugs fixed
 ----------
 
+* #11634: Fixed two more bugs in inheritance diagrams that resulted in
+  broken links.
+  Patch by Albert Shih.
+
 Testing
 -------
 

sphinx/ext/graphviz.py

@@ -21,7 +21,7 @@
 from sphinx.errors import SphinxError
 from sphinx.locale import _, __
 from sphinx.util import logging
-from sphinx.util.docutils import SphinxDirective, SphinxTranslator
+from sphinx.util.docutils import SphinxDirective
 from sphinx.util.i18n import search_image_for_language
 from sphinx.util.nodes import set_source_info
 from sphinx.util.osutil import ensuredir
@@ -218,7 +218,8 @@ def run(self) -> list[Node]:
             return [figure]
 
 
-def fix_svg_relative_paths(self: SphinxTranslator, filepath: str) -> None:
+def fix_svg_relative_paths(self: HTML5Translator | LaTeXTranslator | TexinfoTranslator,
+                           filepath: str) -> None:
     """Change relative links in generated svg files to be relative to imgpath."""
     tree = ET.parse(filepath)  # NoQA: S314
     root = tree.getroot()
@@ -230,16 +231,15 @@ def fix_svg_relative_paths(self: SphinxTranslator, filepath: str) -> None:
         root.findall('.//svg:image[@xlink:href]', ns),
         root.findall('.//svg:a[@xlink:href]', ns),
     ):
-        scheme, hostname, url, query, fragment = urlsplit(element.attrib[href_name])
+        scheme, hostname, rel_uri, query, fragment = urlsplit(element.attrib[href_name])
         if hostname:
             # not a relative link
             continue
 
-        old_path = path.join(self.builder.outdir, url)
-        new_path = path.relpath(
-            old_path,
-            start=path.join(self.builder.outdir, self.builder.imgpath),
-        )
+        doc_dir = (self.builder.outdir / self.builder.current_docname).parent
+        old_path = doc_dir / rel_uri
+        img_path = doc_dir / self.builder.imgpath
+        new_path = path.relpath(old_path, start=img_path)
         modified_url = urlunsplit((scheme, hostname, new_path, query, fragment))
 
         element.set(href_name, modified_url)
@@ -249,7 +249,8 @@ def fix_svg_relative_paths(self: SphinxTranslator, filepath: str) -> None:
         tree.write(filepath)
 
 
-def render_dot(self: SphinxTranslator, code: str, options: dict, format: str,
+def render_dot(self: HTML5Translator | LaTeXTranslator | TexinfoTranslator,
+               code: str, options: dict, format: str,
                prefix: str = 'graphviz', filename: str | None = None,
                ) -> tuple[str | None, str | None]:
     """Render graphviz code into a PNG or PDF output file."""
@@ -294,8 +295,8 @@ def render_dot(self: SphinxTranslator, code: str, options: dict, format: str,
         logger.warning(__('dot command %r cannot be run (needed for graphviz '
                           'output), check the graphviz_dot setting'), graphviz_dot)
         if not hasattr(self.builder, '_graphviz_warned_dot'):
-            self.builder._graphviz_warned_dot = {}  # type: ignore[attr-defined]
-        self.builder._graphviz_warned_dot[graphviz_dot] = True  # type: ignore[attr-defined]
+            self.builder._graphviz_warned_dot = {}  # type: ignore[union-attr]
+        self.builder._graphviz_warned_dot[graphviz_dot] = True
         return None, None
     except CalledProcessError as exc:
         raise GraphvizError(__('dot exited with error:\n[stderr]\n%r\n'

sphinx/ext/inheritance_diagram.py

@@ -36,6 +36,7 @@ class E(B): pass
 import re
 from collections.abc import Iterable, Sequence
 from importlib import import_module
+from os import path
 from typing import TYPE_CHECKING, Any, cast
 
 from docutils import nodes
@@ -417,7 +418,7 @@ def html_visit_inheritance_diagram(self: HTML5Translator, node: inheritance_diag
 
     # Create a mapping from fully-qualified class names to URLs.
     graphviz_output_format = self.builder.env.config.graphviz_output_format.upper()
-    current_filename = self.builder.current_docname + self.builder.out_suffix
+    current_filename = path.basename(self.builder.current_docname + self.builder.out_suffix)
     urls = {}
     pending_xrefs = cast(Iterable[addnodes.pending_xref], node)
     for child in pending_xrefs:

tests/roots/test-ext-inheritance_diagram/subdir/index.rst

@@ -4,4 +4,6 @@ test-ext-inheritance_diagram subdirectory
 
 .. inheritance-diagram:: test.DocMainLevel
 
+.. inheritance-diagram:: test.DocLowerLevel
+
 .. py:class:: test.DocLowerLevel