The docs for Python3.4 havethis to say about the arguments to the dict constructor:

class dict(**kwarg)
class dict(mapping, **kwarg)
class dict(iterable, **kwarg)

    Return a new dictionary initialized from an optional positional argument and a possibly empty set of keyword arguments.

    If no positional argument is given, an empty dictionary is created. If a positional argument is given and it is a mapping object, a dictionary is created with the same key-value pairs as the mapping object. Otherwise, the positional argument must be an iterator object. Each item in the iterable must itself be an iterator with exactly two objects. The first object of each item becomes a key in the new dictionary, and the second object the corresponding value. If a key occurs more than once, the last value for that key becomes the corresponding value in the new dictionary.

This paragraph uses the term iterator twice when it should talk about an iterable instead.
I'm attaching the patch for this.

Best,
Wolfgang

LGTM.

New changeset 78da27d6f28f by Terry Jan Reedy in branch '2.7':
Issue 21533: Dicts take iterables, not iterators. Patch by Wolfgang Maier.
http://hg.python.org/cpython/rev/78da27d6f28f

New changeset 28665dc3a696 by Terry Jan Reedy in branch '3.4':
Issue 21533: Dicts take iterables, not iterators. Patch by Wolfgang Maier.
http://hg.python.org/cpython/rev/28665dc3a696

Thanks for catching this, and for the patch.