Retrieving XML data from SQL Server via FreeTDS yields a bus error

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What steps will reproduce the problem?
1. Use pyodbc to access a SQL Server database which has a table <tbl> which 
contains a column <col> which has the xml datatype.
2. c.execute("select top 1 <col> from <tbl> where <col> is not null")
3. c.fetchall()

What is the expected output? What do you see instead?

I expect to see the contents of the field. Instead, I get a bus error.

What version of the product are you using? On what operating system?

pyodbc 2.1.8
MacOS X 10.6.4
Python 2.6

Please provide any additional information below.

FreeTDS CVS checkout from 11/16/2010
iODBC driver manager
SQL Server 2008 RTM

gdb tells me that the bus error is 

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: KERN_PROTECTION_FAILURE at address: 0x00000004
0x0038fabf in GetDataString (cur=0x7028e0, iCol=<value temporarily unavailable, 
due to optimizations>) at pyodbc-2.1.8/src/getdata.cpp:194
194         if (PyString_CheckExact(bufferOwner))

I suspect that this is related to issue 97. My value for sys.maxunicode:

65535

For what it's worth, the minimum datalength in the table I'm accessing is 1826.

Original issue reported on code.google.com by s...@mitre.org on 17 Nov 2010 at 8:08