fix(lib): continue search for later named siblings in

`ts_tree_cursor_current_status`

By terminating early on `has_later_siblings`, `has_later_named_siblings`
was incorrectly reported as `false` in some cases. This led to the
execution of some queries to terminate early.

Also remove some dead branches inside `ts_tree_cursor_current_status`.

Co-authored-by: Will Lillis <will.lillis24@gmail.com>
(cherry picked from commit 308aee0)

Author: 2 people

crates/cli/src/tests/query_test.rs

@@ -6406,3 +6406,64 @@ export default grammar({
 
     assert_query_matches(&language, &query, source, &[(0, vec![("tuple", "()")])]);
 }
+
+#[test]
+fn test_last_child_anchor_looks_past_hidden_repeat() {
+    let language = get_test_fixture_language("last_child_anchor_past_hidden_repeat");
+
+    let source = "T a.b.c\nL a.b.c\nN a!.b!.c\n";
+
+    let query = Query::new(
+        &language,
+        "
+        (trailing_sep (name) @last .)
+        (leading_sep (name) @last .)
+        (trailing_named (name) @last .)
+        ",
+    )
+    .unwrap();
+
+    assert_query_matches(
+        &language,
+        &query,
+        source,
+        &[
+            (0, vec![("last", "c")]),
+            (1, vec![("last", "c")]),
+            (2, vec![("last", "c")]),
+        ],
+    );
+
+    let query = Query::new(
+        &language,
+        "
+        (trailing_sep . (name) @first)
+        (trailing_sep (name) @a . (name) @b)
+        ",
+    )
+    .unwrap();
+
+    assert_query_matches(
+        &language,
+        &query,
+        source,
+        &[
+            (0, vec![("first", "a")]),
+            (1, vec![("a", "a"), ("b", "b")]),
+            (1, vec![("a", "b"), ("b", "c")]),
+        ],
+    );
+}
+
+#[test]
+fn test_last_child_anchor_looks_past_hidden_node() {
+    allocations::record(|| {
+        let language = get_language("c");
+
+        let query = Query::new(&language, "(translation_unit (_) @last .)").unwrap();
+
+        let source = "enum E { A };\nint x;\nint y;\n";
+
+        assert_query_matches(&language, &query, source, &[(0, vec![("last", "int y;")])]);
+    });
+}

lib/src/tree_cursor.c

@@ -552,8 +552,10 @@ void ts_tree_cursor_current_status(
       (*supertype_count)++;
     }
 
-    // Determine if the current node has later siblings.
-    if (!*has_later_siblings) {
+    // Determine if the current node has later siblings. A later *anonymous*
+    // sibling settles `has_later_siblings` but says nothing about later *named*
+    // siblings.
+    if (!*has_later_named_siblings) {
       unsigned sibling_count = parent_entry->subtree->ptr->child_count;
       unsigned structural_child_index = entry->structural_child_index;
       if (!ts_subtree_extra(*entry->subtree)) structural_child_index++;
@@ -565,14 +567,12 @@ void ts_tree_cursor_current_status(
         );
         if (sibling_metadata.visible) {
           *has_later_siblings = true;
-          if (*has_later_named_siblings) break;
           if (sibling_metadata.named) {
             *has_later_named_siblings = true;
             break;
           }
         } else if (ts_subtree_visible_child_count(sibling) > 0) {
           *has_later_siblings = true;
-          if (*has_later_named_siblings) break;
           if (sibling.ptr->named_child_count > 0) {
             *has_later_named_siblings = true;
             break;

test/fixtures/test_grammars/last_child_anchor_past_hidden_repeat/corpus.txt

@@ -0,0 +1,43 @@
+=========================================
+Repeat ending with an anonymous separator
+=========================================
+
+T a.b.c
+
+---
+
+(source_file
+  (trailing_sep
+    (name)
+    (name)
+    (name)))
+
+===============================
+Repeat ending with a named node
+===============================
+
+L a.b.c
+
+---
+
+(source_file
+  (leading_sep
+    (name)
+    (name)
+    (name)))
+
+============================================================
+Repeat ending with an anonymous separator, preceded by a tag
+============================================================
+
+N a!.b!.c
+
+---
+
+(source_file
+  (trailing_named
+    (name)
+    (tag)
+    (name)
+    (tag)
+    (name)))

test/fixtures/test_grammars/last_child_anchor_past_hidden_repeat/grammar.js

@@ -0,0 +1,25 @@
+// These three rules all parse to a flat run of `name` children, but `repeat`
+// builds a different hidden `_repeat1` node for each of them, so a query's
+// trailing `.` anchor has to walk past a different set of hidden nodes to
+// decide whether a `name` is the last *named* child of its rule.
+export default grammar({
+  name: 'last_child_anchor_past_hidden_repeat',
+
+  rules: {
+    source_file: $ => repeat(choice($.trailing_sep, $.leading_sep, $.trailing_named)),
+
+    // The hidden repeat ends with an anonymous node, and a named node follows it.
+    trailing_sep: $ => seq('T', repeat(seq($.name, '.')), $.name),
+
+    // The hidden repeat ends with a named node.
+    leading_sep: $ => seq('L', $.name, repeat(seq('.', $.name))),
+
+    // Same shape as `trailing_sep`, but a named node sits inside the repeat
+    // ahead of the anonymous separator.
+    trailing_named: $ => seq('N', repeat(seq($.name, $.tag, '.')), $.name),
+
+    tag: _ => '!',
+
+    name: _ => /[a-z]+/,
+  }
+});