Merged revisions 88460,88464,88466,88486,88511,88652 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/branches/py3k

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  r88460 | antoine.pitrou | 2011-02-21 19:03:13 +0100 (lun., 21 févr. 2011) | 4 lines

  Issue #10276: Fix the results of zlib.crc32() and zlib.adler32() on buffers
  larger than 4GB.  Patch by Nadeem Vawda.
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  r88464 | antoine.pitrou | 2011-02-21 20:05:08 +0100 (lun., 21 févr. 2011) | 3 lines

  Fix issues on 32-bit systems introduced by r88460
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  r88466 | antoine.pitrou | 2011-02-21 20:28:40 +0100 (lun., 21 févr. 2011) | 3 lines

  Fix compile error under MSVC introduced by r88460.
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  r88486 | antoine.pitrou | 2011-02-22 00:41:12 +0100 (mar., 22 févr. 2011) | 5 lines

  Issue #4681: Allow mmap() to work on file sizes and offsets larger than
  4GB, even on 32-bit builds.  Initial patch by Ross Lagerwall, adapted for
  32-bit Windows.
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  r88511 | antoine.pitrou | 2011-02-22 22:42:56 +0100 (mar., 22 févr. 2011) | 4 lines

  Issue #11277: finally fix Snow Leopard crash following r88460.
  (probably an OS-related issue with mmap)
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  r88652 | antoine.pitrou | 2011-02-26 16:58:05 +0100 (sam., 26 févr. 2011) | 4 lines

  Issue #9931: Fix hangs in GUI tests under Windows in certain conditions.
  Patch by Hirokazu Yamamoto.
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diff --git a/Modules/zlibmodule.c b/Modules/zlibmodule.c
index 54ab9a1..c78cf42 100644
--- a/Modules/zlibmodule.c
+++ b/Modules/zlibmodule.c
@@ -931,8 +931,18 @@
     /* Releasing the GIL for very small buffers is inefficient
        and may lower performance */
     if (pbuf.len > 1024*5) {
+        unsigned char *buf = pbuf.buf;
+        Py_ssize_t len = pbuf.len;
+
         Py_BEGIN_ALLOW_THREADS
-        adler32val = adler32(adler32val, pbuf.buf, pbuf.len);
+        /* Avoid truncation of length for very large buffers. adler32() takes
+           length as an unsigned int, which may be narrower than Py_ssize_t. */
+        while (len > (size_t) UINT_MAX) {
+            adler32val = adler32(adler32val, buf, UINT_MAX);
+            buf += (size_t) UINT_MAX;
+            len -= (size_t) UINT_MAX;
+        }
+        adler32val = adler32(adler32val, buf, len);
         Py_END_ALLOW_THREADS
     } else {
         adler32val = adler32(adler32val, pbuf.buf, pbuf.len);
@@ -959,8 +969,18 @@
     /* Releasing the GIL for very small buffers is inefficient
        and may lower performance */
     if (pbuf.len > 1024*5) {
+        unsigned char *buf = pbuf.buf;
+        Py_ssize_t len = pbuf.len;
+
         Py_BEGIN_ALLOW_THREADS
-        signed_val = crc32(crc32val, pbuf.buf, pbuf.len);
+        /* Avoid truncation of length for very large buffers. crc32() takes
+           length as an unsigned int, which may be narrower than Py_ssize_t. */
+        while (len > (size_t) UINT_MAX) {
+            crc32val = crc32(crc32val, buf, UINT_MAX);
+            buf += (size_t) UINT_MAX;
+            len -= (size_t) UINT_MAX;
+        }
+        signed_val = crc32(crc32val, buf, len);
         Py_END_ALLOW_THREADS
     } else {
         signed_val = crc32(crc32val, pbuf.buf, pbuf.len);