Fix infer_call_result() crash on methods called with_metaclass() (#2118)

Author: jacobtylerwalls

ChangeLog

@@ -61,6 +61,9 @@ What's New in astroid 2.15.3?
 =============================
 Release date: TBA
 
+* Fix ``infer_call_result()`` crash on methods called ``with_metaclass()``.
+
+  Closes #1735
 
 
 What's New in astroid 2.15.2?

astroid/nodes/scoped_nodes/scoped_nodes.py

@@ -1692,10 +1692,18 @@ def infer_call_result(self, caller=None, context: InferenceContext | None = None
         # generators, and filter it out later.
         if (
             self.name == "with_metaclass"
+            and caller is not None
             and len(self.args.args) == 1
             and self.args.vararg is not None
         ):
-            metaclass = next(caller.args[0].infer(context), None)
+            if isinstance(caller.args, Arguments):
+                metaclass = next(caller.args.args[0].infer(context), None)
+            elif isinstance(caller.args, list):
+                metaclass = next(caller.args[0].infer(context), None)
+            else:
+                raise TypeError(  # pragma: no cover
+                    f"caller.args was neither Arguments nor list; got {type(caller.args)}"
+                )
             if isinstance(metaclass, ClassDef):
                 try:
                     class_bases = [

tests/test_inference.py

@@ -4055,6 +4055,11 @@ class C:
             inferred = next(node.infer())
             self.assertRaises(InferenceError, next, inferred.infer_call_result(node))
 
+    def test_infer_call_result_with_metaclass(self) -> None:
+        node = extract_node("def with_metaclass(meta, *bases): return 42")
+        inferred = next(node.infer_call_result(caller=node))
+        self.assertIsInstance(inferred, nodes.Const)
+
     def test_context_call_for_context_managers(self) -> None:
         ast_nodes = extract_node(
             """