stack: make a deep copy of `dependencies` before modifying its items
The algorithm later on in this method uses .remove() to remove individual
elements from items in dependencies, which before this patch modified the
cached property contents. So for further use that dictionary was in the form of
{1: set([])}, i.e. all sets were empty.
This deep copy block could be way simpler, but the problem is that sometimes we
get lists of _succs() from evolvebits.builddependencies(). Note: this happens
only in topic's stack version of builddependencies() and it looks like a
suboptimal way to handle multiple successors (see evolve's counterpart
function).
stack.builddependencies method is removed, it has served its purpose (see the
previous patch).
[flake8]
ignore =
#closing bracket does not match indentation of opening bracket's line
E123,
# closing bracket does not match visual indentation
E124,
# visually indented line with same indent as next logical line
E129,
# at least two spaces before inline comment
E261,
# too many leading '#' for block comment
E266,
# expected 2 blank lines, found 0
E302,
# expected 2 blank lines after end of function or class
E305,
# module level import not at top of file
E402,
# line too long (82 > 79 characters)
E501,
# do not assign a lambda expression, use a def
E731,
# class names should use CapWords convention
N801,
# line break occurred before a binary operator
W503
builtins=xrange, execfile