fix: Remove outdated barrier when automatically inserting drops

guppylang-internals/src/guppylang_internals/compiler/core.py

@@ -721,10 +721,7 @@ def insert_drops(hugr: Hugr[OpVarCov]) -> None:
         data = hugr[node]
         # Iterating over `node.outputs()` doesn't work reliably since it sometimes
         # raises an `IncompleteOp` exception. Instead, we query the number of out ports
-        # and look them up by index. However, this method is *also* broken when
-        # inspecting `FuncDefn` nodes due to https://github.com/quantinuum/hugr/issues/2438.
-        if isinstance(data.op, ops.FuncDefn):
-            continue
+        # and look them up by index.
         for i in range(hugr.num_out_ports(node)):
             port = node.out(i)
             kind = hugr.port_kind(port)

tests/integration/test_drop_insertion.py

@@ -137,3 +137,23 @@ def main() -> AffineTy:
     hugr = main.compile_function()
     assert num_drops(hugr) == 4
     validate(hugr)
+
+
+def test_drop_with_multiple_funcdefns(validate):
+    """Regression test for https://github.com/quantinuum/guppylang/issues/1516.
+
+    Ensures insert_drops correctly iterates over FuncDefn nodes instead of
+    skipping them, and still inserts the right number of drops.
+    """
+
+    @guppy
+    def helper() -> AffineTy:
+        return make()
+
+    @guppy
+    def main(x: AffineTy @ owned) -> None:
+        pass  # x is dropped here
+
+    hugr = main.compile_function()
+    assert num_drops(hugr) == 1
+    validate(hugr)