id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
9989	removal flaw in django.dispatch.Signal.disconnect	(removed)	nobody	"Eyeballing cleanup in signals, spotted a bit of whackyness trying to cleanse a list via enumerate usage; presume the author tried removing from the list directory (which blows up since that invalidates the listiter) and came up w/ this instead.  Flaw with it is that enumerate continues to increase the index even if you change the list under it's feet- in other words, you skip the item immediately following a deletion.  One reason list comps are usually better in this case (although dependant on # of items and deletions of course).

So... that should be using list.remove and catching ValueError where it doesn't exist.  Quite a bit faster due to shifting comparison to cpy, and stopping the search after the first find.
Clarifying the latter, a quick read of Signal.connect shows it disallows redundant connections to the same 'key'; meaning that the enumerate code in place right now is daft for continuing it's search for more to wipe- essentially a mismatch between connect/disconnect (guessing it crept in when someone tweaking signal.connect to disallow redundant registrations).

basically convert
{{{
for idx, (r_key, _) in self.receivers:
 if r_key == lookup_key:
  del self.receives[idx]
}}}
into
{{{
try:
 self.receivers.remove(lookup_key)
except ValueError:
 pass
}}}
'nuff said."		closed	Core (Other)	1.0		fixed			Accepted	0	0	0	0	0	0