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test_pickle works on sizeof(long)==8 boxes again. 

pickle.py
    The code implicitly assumed that all ints fit in 4 bytes, causing all
    sorts of mischief (from nonsense results to corrupted pickles).
    Repaired that.
marshal.c
    The int marshaling code assumed that right shifts of signed longs
    sign-extend.  Repaired that.
This commit is contained in:
Tim Peters 2001-04-10 05:02:52 +00:00
parent d8ae7c2999
commit 44714007e8
2 changed files with 19 additions and 12 deletions
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29
Lib/pickle.py
View File

@ -243,18 +243,25 @@ class Pickler:
def save_int(self, object):
if self.bin:
i = mdumps(object)[1:]
if i[-2:] == '\000\000':
if i[-3] == '\000':
self.write(BININT1 + i[:-3])
return
self.write(BININT2 + i[:-2])
# If the int is small enough to fit in a signed 4-byte 2's-comp
# format, we can store it more efficiently than the general
# case.
high_bits = object >> 31 # note that Python shift sign-extends
if high_bits == 0 or high_bits == -1:
# All high bits are copies of bit 2**31, so the value
# fits in a 4-byte signed int.
i = mdumps(object)[1:]
assert len(i) == 4
if i[-2:] == '\000\000': # fits in 2-byte unsigned int
if i[-3] == '\000': # fits in 1-byte unsigned int
self.write(BININT1 + i[0])
else:
self.write(BININT2 + i[:2])
else:
self.write(BININT + i)
return
self.write(BININT + i)
else:
self.write(INT + `object` + '\n')
# Text pickle, or int too big to fit in signed 4-byte format.
self.write(INT + `object` + '\n')
dispatch[IntType] = save_int
def save_long(self, object):

2
Python/marshal.c
View File

@ -126,7 +126,7 @@ w_object(PyObject *v, WFILE *p)
else if (PyInt_Check(v)) {
long x = PyInt_AS_LONG((PyIntObject *)v);
#if SIZEOF_LONG > 4
long y = x>>31;
long y = Py_ARITHMETIC_RIGHT_SHIFT(long, x, 31);
if (y && y != -1) {
w_byte(TYPE_INT64, p);
w_long64(x, p);