CRC-32 for 64-bit systems is calculated incorrectly,
resulting in corrupted ODG exported files.

https://bugs.launchpad.net/inkscape/+bug/275519
https://bugzilla.redhat.com/show_bug.cgi?id=499088

Lubomir Rintel

diff -up inkscape/src/dom/util/ziptool.cpp.crc32 inkscape/src/dom/util/ziptool.cpp
--- inkscape/src/dom/util/ziptool.cpp.crc32	2009-05-18 06:12:56.000000000 +0200
+++ inkscape/src/dom/util/ziptool.cpp	2009-05-18 06:13:31.000000000 +0200
@@ -158,6 +158,8 @@ void Crc32::reset()
 void Crc32::update(unsigned char b)
 {
     unsigned long c = ~value;
+
+    c &= 0xffffffff;
     c = crc_table[(c ^ b) & 0xff] ^ (c >> 8);
     value = ~c;
 }