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| author | Raymond Hettinger <python@rcn.com> | 2004-06-10 18:42:15 (GMT) |
|---|---|---|
| committer | Raymond Hettinger <python@rcn.com> | 2004-06-10 18:42:15 (GMT) |
| commit | 57c2d930f688ca50248241919bd815c85bf39939 (patch) | |
| tree | 6b233b7dfd1e3ced0697399af4e510673fe849ce | |
| parent | bce036b49ee84333a325a932013592662dbe09d9 (diff) | |
| download | cpython-57c2d930f688ca50248241919bd815c85bf39939.zip cpython-57c2d930f688ca50248241919bd815c85bf39939.tar.gz cpython-57c2d930f688ca50248241919bd815c85bf39939.tar.bz2 | |
Add a final permutation step to the tuple hash function.
Prevents a collision pattern that occurs with nested tuples.
(Yitz Gale provided code that repeatably demonstrated the weakness.)
| -rw-r--r-- | Misc/ACKS | 1 | ||||
| -rw-r--r-- | Objects/tupleobject.c | 1 |
2 files changed, 2 insertions, 0 deletions
@@ -190,6 +190,7 @@ Gyro Funch Peter Funk Geoff Furnish Lele Gaifax +Yitzchak Gale Raymund Galvin Nitin Ganatra Fred Gansevles diff --git a/Objects/tupleobject.c b/Objects/tupleobject.c index ff20b43..ea7d753 100644 --- a/Objects/tupleobject.c +++ b/Objects/tupleobject.c @@ -280,6 +280,7 @@ tuplehash(PyTupleObject *v) x = (x ^ y) * mult; mult += 82520L + len + len; } + x += 97531L; if (x == -1) x = -2; return x; |