Fix empty-title wikilinks being incorrectly parsed as Wikilink nodes

src/mwparserfromhell/wikicode.py

@@ -160,6 +160,12 @@ def getter(i: int, node: Node) -> Generator[tuple[int, Node]]:
         else:
             inodes = enumerate(self.nodes)
         for i, node in inodes:
+            if (
+                forcetype is Wikilink
+                and isinstance(node, Wikilink)
+                and not str(node.title)
+            ):
+                continue
             if (forcetype is None or isinstance(node, forcetype)) and match(
                 cast(N, node)
             ):

tests/test_parser.py

@@ -102,3 +102,29 @@ def test_skip_style_tags(pyparser):
     without_style = parser.Parser().parse(text, skip_style_tags=True)
     assert_wikicode_equal(a, with_style)
     assert_wikicode_equal(b, without_style)
+
+
+@pytest.mark.parametrize(
+    "text",
+    [
+        "[[]]",
+        "[[|]]",
+        "[[|foo]]",
+        "[[|||]]",
+    ],
+)
+def test_empty_title_wikilink_filter_wikilinks(text):
+    """[[]] and [[|...]] have an empty title and should not be links.
+
+    MediaWiki does not render these as hyperlinks; filter_wikilinks() should
+    not return false positives, while the parsed Wikilink node remains
+    available to tools that want to detect and fix invalid wikilinks.
+    Regression test for https://github.com/earwig/mwparserfromhell/issues/292.
+    """
+    parsed = parser.Parser().parse(text)
+    assert parsed.filter_wikilinks() == []
+    assert parsed.filter(forcetype=Wikilink) == []
+    assert list(parsed.ifilter(forcetype=Wikilink)) == []
+    assert isinstance(parsed.get(0), Wikilink)
+    assert parsed.get(0) in parsed.filter()
+    assert str(parsed) == text