From 5f379da544bec9fe1ac64ea162041e7e3f6c3ddb Mon Sep 17 00:00:00 2001
From: Amaan Qureshi <amaanq12@gmail.com>
Date: Fri, 3 Jan 2025 22:31:50 -0500
Subject: [PATCH] fix(lib): prevent wildcards from incorrectly marking child
 patterns as infallible

When a pattern appears under a wildcard parent (like "(_ (expr))"), we
were incorrectly marking it as infallible. The parent_pattern_guaranteed
flag only means the pattern will match after finding the right wildcard
parent, not that any wildcard parent will work.
---
 cli/src/tests/query_test.rs | 30 ++++++++++++++++++++++++++++++
 lib/src/query.c             |  2 +-
 2 files changed, 31 insertions(+), 1 deletion(-)

diff --git a/cli/src/tests/query_test.rs b/cli/src/tests/query_test.rs
index 6e722aef..b6b76cd1 100644
--- a/cli/src/tests/query_test.rs
+++ b/cli/src/tests/query_test.rs
@@ -5520,3 +5520,33 @@ fn f() {
     );
     assert_eq!(matches, flipped_matches);
 }
+
+#[test]
+fn test_wildcard_parent_allows_fallible_child_patterns() {
+    let language = get_language("javascript");
+    let mut parser = Parser::new();
+    parser.set_language(&language).unwrap();
+
+    let source_code = r#"
+function foo() {
+    "bar"
+}
+    "#;
+
+    let query = Query::new(
+        &language,
+        "(function_declaration
+          (_
+            (expression_statement)
+          )
+        ) @part",
+    )
+    .unwrap();
+
+    assert_query_matches(
+        &language,
+        &query,
+        source_code,
+        &[(0, vec![("part", "function foo() {\n    \"bar\"\n}")])],
+    );
+}
diff --git a/lib/src/query.c b/lib/src/query.c
index a594342f..12829a20 100644
--- a/lib/src/query.c
+++ b/lib/src/query.c
@@ -3004,7 +3004,7 @@ bool ts_query__step_is_fallible(
   return (
     next_step->depth != PATTERN_DONE_MARKER &&
     next_step->depth > step->depth &&
-    !next_step->parent_pattern_guaranteed
+    (!next_step->parent_pattern_guaranteed || step->symbol == WILDCARD_SYMBOL)
   );
 }