cPickle.c: Full support for the new LONG1 and LONG4. Added comments.

Assorted code cleanups; e.g., sizeof(char) is 1 by definition, so there's
no need to do things like multiply by sizeof(char) in hairy malloc
arguments.  Fixed an undetected-overflow bug in readline_file().

longobject.c:  Fixed a really stupid bug in the new _PyLong_NumBits.

pickle.py:  Fixed stupid bug in save_long():  When proto is 2, it
wrote LONG1 or LONG4, but forgot to return then -- it went on to
append the proto 1 LONG opcode too.
Fixed equally stupid cancelling bugs in load_long1() and
load_long4():  they *returned* the unpickled long instead of pushing
it on the stack.  The return values were ignored.  Tests passed
before only because save_long() pickled the long twice.

Fixed bugs in encode_long().

Noted that decode_long() is quadratic-time despite our hopes,
because long(string, 16) is still quadratic-time in len(string).
It's hex() that's linear-time.  I don't know a way to make decode_long()
linear-time in Python, short of maybe transforming the 256's-complement
bytes into marshal's funky internal format, and letting marshal decode
that.  It would be more valuable to make long(string, 16) linear time.

pickletester.py:  Added a global "protocols" vector so tests can try
all the protocols in a sane way.  Changed test_ints() and test_unicode()
to do so.  Added a new test_long(), but the tail end of it is disabled
because it "takes forever" under pickle.py (but runs very quickly under
cPickle:  cPickle proto 2 for longs is linear-time).

Lib/test/pickletester.py

@@ -1,6 +1,11 @@
 import unittest
 from test.test_support import TestFailed, have_unicode, TESTFN
 
+# Tests that try a number of pickle protocols should have a
+#     for proto in protocols:
+# kind of outer loop.  Bump the 3 to 4 if/when protocol 3 is invented.
+protocols = range(3)
+
 class C:
     def __cmp__(self, other):
         return cmp(self.__dict__, other.__dict__)
@@ -28,6 +33,9 @@ class metaclass(type):
 class use_metaclass(object):
     __metaclass__ = metaclass
 
+# DATA and BINDATA are the protocol 0 and protocol 1 pickles of the object
+# returned by create_data().
+
 # break into multiple strings to avoid confusing font-lock-mode
 DATA = """(lp1
 I0
@@ -210,20 +218,22 @@ class AbstractPickleTests(unittest.TestCase):
         def test_unicode(self):
             endcases = [unicode(''), unicode('<\\u>'), unicode('<\\\u1234>'),
                         unicode('<\n>'),  unicode('<\\>')]
-            for u in endcases:
-                p = self.dumps(u)
-                u2 = self.loads(p)
-                self.assertEqual(u2, u)
+            for proto in protocols:
+                for u in endcases:
+                    p = self.dumps(u, proto)
+                    u2 = self.loads(p)
+                    self.assertEqual(u2, u)
 
     def test_ints(self):
         import sys
-        n = sys.maxint
-        while n:
-            for expected in (-n, n):
-                s = self.dumps(expected)
-                n2 = self.loads(s)
-                self.assertEqual(expected, n2)
-            n = n >> 1
+        for proto in protocols:
+            n = sys.maxint
+            while n:
+                for expected in (-n, n):
+                    s = self.dumps(expected, proto)
+                    n2 = self.loads(s)
+                    self.assertEqual(expected, n2)
+                n = n >> 1
 
     def test_maxint64(self):
         maxint64 = (1L << 63) - 1
@@ -235,6 +245,34 @@ class AbstractPickleTests(unittest.TestCase):
         data = 'I' + str(maxint64) + 'JUNK\n.'
         self.assertRaises(ValueError, self.loads, data)
 
+    def test_long(self):
+        for proto in protocols:
+            # 256 bytes is where LONG4 begins
+            for nbits in 1, 8, 8*254, 8*255, 8*256, 8*257:
+                nbase = 1L << nbits
+                for npos in nbase-1, nbase, nbase+1:
+                    for n in npos, -npos:
+                        pickle = self.dumps(n, proto)
+                        got = self.loads(pickle)
+                        self.assertEqual(n, got)
+        # Try a monster.  This is quadratic-time in protos 0 & 1, so don't
+        # bother with those.
+        # XXX Damn.  pickle.py is still quadratic-time here, due to
+        # XXX long(string, 16).  cPickle runs this in an eyeblink, but I
+        # XXX gave up waiting for pickle.py to get beyond "loading".  Giving
+        # XXX up for now.
+        return
+        print "building long"
+        nbase = long("deadbeeffeedface", 16)
+        nbase += nbase << 1000000
+        for n in nbase, -nbase:
+            print "dumping"
+            p = self.dumps(n, 2)
+            print "loading"
+            got = self.loads(p)
+            print "checking"
+            self.assertEqual(n, got)
+
     def test_reduce(self):
         pass