Fleshed out WeakKeyDictionary.__delitem__ NEWS to cover issues raised on
Python-Dev. Fixed typos in test comments. Added some trivial new test
guts to show the parallelism (now) among __delitem__, __setitem__ and
__getitem__ wrt error conditions.
Still a bugfix candidate for 2.2.3 final, but waiting for Fred to get a
chance to chime in.
diff --git a/Misc/NEWS b/Misc/NEWS
index bc15f42..9c9e3f8 100644
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -12,11 +12,19 @@
Core and builtins
-----------------
-- SF bug 742860: WeakKeyDictionary __delitem__ uses iterkeys. This
- wasn't as threadsafe as it should be, was very inefficient, and could
- raise RuntimeError if another thread mutated the dict during
- __delitem__, or if a comparison function mutated it. A new
- implementation of WeakKeyDictionary.__delitem__ repairs all that.
+- SF bug 742860: "WeakKeyDictionary __delitem__ uses iterkeys". This
+ wasn't threadsafe, was very inefficient (expected time O(len(dict))
+ instead of O(1)), and could raise a spurious RuntimeError if another
+ thread mutated the dict during __delitem__, or if a comparison function
+ mutated it. It also neglected to raise KeyError when the key wasn't
+ present; didn't raise TypeError when the key wasn't of a weakly
+ referencable type; and broke various more-or-less obscure dict
+ invariants by using a sequence of equality comparisons over the whole
+ set of dict keys instead of computing the key's hash code to narrow
+ the search to those keys with the same hash code. All of these are
+ considered to be bugs. A new implementation of __delitem__ repairs all
+ that, but note that fixing these bugs may change visible behavior in
+ code relying (whether intentionally or accidentally) on old behavior.
- SF bug 705231: builtin pow() no longer lets the platform C pow()
raise -1.0 to integer powers, because (at least) glibc gets it wrong