Do not use query components in URLs for assets in EPUB rendering

CHANGES.rst

@@ -67,6 +67,8 @@ Bugs fixed
   Patch by James Addison.
 * #11886: Print the Jinja2 template path chain in ``TemplateNotFound`` exceptions.
   Patch by Colin Marquardt.
+* #11598: Do not use query components in URLs for assets in EPUB rendering.
+  Patch by David Runge.
 
 Testing
 -------

sphinx/builders/html/__init__.py

@@ -1051,8 +1051,10 @@ def css_tag(css: _CascadingStyleSheet) -> str:
                      for key, value in css.attributes.items()
                      if value is not None]
             uri = pathto(os.fspath(css.filename), resource=True)
-            if checksum := _file_checksum(outdir, css.filename):
-                uri += f'?v={checksum}'
+            # the EPUB format does not allow the use of query components
+            if self.name != 'epub':
+                if checksum := _file_checksum(outdir, css.filename):
+                    uri += f'?v={checksum}'
             return f'<link {" ".join(sorted(attrs))} href="{uri}" />'
 
         ctx['css_tag'] = css_tag
@@ -1079,8 +1081,10 @@ def js_tag(js: _JavaScript | str) -> str:
                 # https://docs.mathjax.org/en/v2.7-latest/configuration.html#considerations-for-using-combined-configuration-files
                 # https://github.com/sphinx-doc/sphinx/issues/11658
                 pass
-            elif checksum := _file_checksum(outdir, js.filename):
-                uri += f'?v={checksum}'
+            # the EPUB format does not allow the use of query components
+            elif self.name != 'epub':
+                if checksum := _file_checksum(outdir, js.filename):
+                    uri += f'?v={checksum}'
             if attrs:
                 return f'<script {" ".join(sorted(attrs))} src="{uri}"></script>'
             return f'<script src="{uri}"></script>'