Remove "possible bug" TODO; investigated, no bug. Add comment.

Technologicat · Technologicat · commit e9c78901ece6 · 2019-11-13T03:08:28.000+02:00
diff --git a/unpythonic/syntax/letdo.py b/unpythonic/syntax/letdo.py
@@ -301,7 +301,8 @@ def find_deletes(tree, collect, **kw):
     names = []
     lines = []
     for j, expr in enumerate(tree.elts, start=1):
-        # TODO: do we need the recursion here? Won't this trigger false positives for nested do[] expressions?
+        # Despite the recursion, this will not trigger false positives for nested do[] expressions,
+        # because do[] is a second-pass macro, so they expand from inside out.
         expr, newnames = find_localdefs.recurse_collect(expr)
         expr, deletednames = find_deletes.recurse_collect(expr)
         assert not (newnames and deletednames), "a do-item may have only local[] or delete[], not both"
