Internal error when using reveal_locals() inside class that contains an inner class

[mthuurne]

While trying to dig deeper on #5914, I ran into an internal error in mypy.

I ran mypy on this code, without any arguments other than the file name:

class Outer:
    class Inner:
        pass
    reveal_locals()

This is the traceback: (paths shortened)

Traceback (most recent call last):
  File ".../bin/mypy", line 11, in <module>
    sys.exit(console_entry())
  File ".../lib/python3.6/site-packages/mypy/__main__.py", line 7, in console_entry
    main(None)
  File ".../lib/python3.6/site-packages/mypy/main.py", line 92, in main
    res = build.build(sources, options, None, flush_errors, fscache)
  File ".../lib/python3.6/site-packages/mypy/build.py", line 155, in build
    result = _build(sources, options, alt_lib_path, flush_errors, fscache)
  File ".../lib/python3.6/site-packages/mypy/build.py", line 204, in _build
    graph = dispatch(sources, manager)
  File ".../lib/python3.6/site-packages/mypy/build.py", line 2172, in dispatch
    process_graph(graph, manager)
  File ".../lib/python3.6/site-packages/mypy/build.py", line 2469, in process_graph
    process_stale_scc(graph, scc, manager)
  File ".../lib/python3.6/site-packages/mypy/build.py", line 2592, in process_stale_scc
    graph[id].type_check_first_pass()
  File ".../lib/python3.6/site-packages/mypy/build.py", line 1730, in type_check_first_pass
    self.type_checker().check_first_pass()
  File ".../lib/python3.6/site-packages/mypy/checker.py", line 282, in check_first_pass
    self.accept(d)
  File ".../lib/python3.6/site-packages/mypy/checker.py", line 393, in accept
    stmt.accept(self)
  File ".../lib/python3.6/site-packages/mypy/nodes.py", line 845, in accept
    return visitor.visit_class_def(self)
  File ".../lib/python3.6/site-packages/mypy/checker.py", line 1536, in visit_class_def
    self.accept(defn.defs)
  File ".../lib/python3.6/site-packages/mypy/checker.py", line 393, in accept
    stmt.accept(self)
  File ".../lib/python3.6/site-packages/mypy/nodes.py", line 910, in accept
    return visitor.visit_block(self)
  File ".../lib/python3.6/site-packages/mypy/checker.py", line 1688, in visit_block
    self.accept(s)
  File ".../lib/python3.6/site-packages/mypy/checker.py", line 393, in accept
    stmt.accept(self)
  File ".../lib/python3.6/site-packages/mypy/nodes.py", line 925, in accept
    return visitor.visit_expression_stmt(self)
  File ".../lib/python3.6/site-packages/mypy/checker.py", line 2602, in visit_expression_stmt
    self.expr_checker.accept(s.expr, allow_none_return=True, always_allow_any=True)
  File ".../lib/python3.6/site-packages/mypy/checkexpr.py", line 3003, in accept
    typ = self.visit_call_expr(node, allow_none_return=True)
  File ".../lib/python3.6/site-packages/mypy/checkexpr.py", line 228, in visit_call_expr
    return self.accept(e.analyzed, self.type_context[-1])
  File ".../lib/python3.6/site-packages/mypy/checkexpr.py", line 3007, in accept
    typ = node.accept(self)
  File ".../lib/python3.6/site-packages/mypy/nodes.py", line 1674, in accept
    return visitor.visit_reveal_expr(self)
  File ".../lib/python3.6/site-packages/mypy/checkexpr.py", line 2362, in visit_reveal_expr
    } if expr.local_nodes is not None else {}
  File ".../lib/python3.6/site-packages/mypy/checkexpr.py", line 2361, in <dictcomp>
    var_node.name(): var_node.type for var_node in expr.local_nodes
AttributeError: 'TypeInfo' object has no attribute 'type'

I'm using mypy 0.641 on Python 3.6.5.

[gvanrossum]

This is due to improper casting in semanal.py where local_nodes is computed. I can quickly fix there.