Prevent creation of multiple tags with the same property

sphinxext/opengraph/__init__.py

@@ -26,12 +26,16 @@
     "heif": "image/heif",
     "tiff": "image/tiff",
 }
+TAG_LIST = []
 
 
 def make_tag(property: str, content: str) -> str:
     # Parse quotation, so they won't break html tags if smart quotes are disabled
-    content = content.replace('"', """)
-    return f'<meta property="{property}" content="{content}" />\n  '
+    if property not in TAG_LIST:
+        TAG_LIST.append(property)
+        content = content.replace('"', "&quot;")
+        return f'<meta property="{property}" content="{content}" />\n  '
+    return ""
 
 
 def make_arbitrary_tags(fields: Dict[str, Any]) -> str:
@@ -49,6 +53,7 @@ def get_tags(
     doctree: nodes.document,
     config: Dict[str, Any],
 ) -> str:
+    TAG_LIST.clear()
     # Get field lists for per-poge overrides
     fields = context["meta"]
     if fields is None:

tests/roots/test-arbitrary-tags/index.rst

@@ -1,4 +1,5 @@
 :og:video: http://example.org/video.mp4
 :og:video:type: video/mp4
+:og:url: http://example.com/
 
 Lorem ipsum dolor sit amet, consectetur adipiscing elit. Suspendisse at lorem ornare, fringilla massa nec, venenatis mi. Donec erat sapien, tincidunt nec rhoncus nec, scelerisque id diam. Orci varius natoque penatibus et magnis dis parturient mauris.

tests/test_options.py

@@ -184,6 +184,8 @@ def test_overrides_complex(og_meta_tags):
 def test_arbitrary_tags(og_meta_tags):
     assert get_tag_content(og_meta_tags, "video") == "http://example.org/video.mp4"
     assert get_tag_content(og_meta_tags, "video:type") == "video/mp4"
+    assert get_tag_content(og_meta_tags, "url") == "http://example.org/index.html"
+    assert len([tag for tag in og_meta_tags if tag.get("property") == "og:url"]) == 1
 
 
 # use same as simple, as configuration is identical to overriden