Comment 2 for bug 502959

I can reproduce this. However, it seems to crash deeply inside of libxml2's
parser, and it isn't immediately obvious how lxml could trigger this.
(xmllint parses the file ok, but doesn't use a dictionary in doing so)

(gdb) bt 25
#0 strlen () at ../sysdeps/x86_64/strlen.S:31

#1 0x00007ffff6593a94 in xmlDictLookup () from /usr/lib/libxml2.so.2

#2 0x00007ffff64f6d24 in ?? () from /usr/lib/libxml2.so.2

#3 0x00007ffff64e8fc3 in xmlParseReference () from /usr/lib/libxml2.so.2

#4 0x00007ffff64e6c28 in xmlParseContent () from /usr/lib/libxml2.so.2

#5 0x00007ffff64e675b in xmlParseElement () from /usr/lib/libxml2.so.2

#6 0x00007ffff64e6c1a in xmlParseContent () from /usr/lib/libxml2.so.2

#7 0x00007ffff64e675b in xmlParseElement () from /usr/lib/libxml2.so.2

#8 0x00007ffff64e6c1a in xmlParseContent () from /usr/lib/libxml2.so.2

#9 0x00007ffff64e675b in xmlParseElement () from /usr/lib/libxml2.so.2

#10 0x00007ffff64e6c1a in xmlParseContent () from /usr/lib/libxml2.so.2

#11 0x00007ffff64e675b in xmlParseElement () from /usr/lib/libxml2.so.2

#12 0x00007ffff64e6c1a in xmlParseContent () from /usr/lib/libxml2.so.2

#13 0x00007ffff64e675b in xmlParseElement () from /usr/lib/libxml2.so.2
#14 0x00007ffff64e6c1a in xmlParseContent () from /usr/lib/libxml2.so.2
#15 0x00007ffff64e675b in xmlParseElement () from /usr/lib/libxml2.so.2
#16 0x00007ffff64e6c1a in xmlParseContent () from /usr/lib/libxml2.so.2
#17 0x00007ffff64e7f3a in xmlParseCtxtExternalEntity () from
/usr/lib/libxml2.so.2
#18 0x00007ffff6597dbf in xmlSAX2GetEntity () from /usr/lib/libxml2.so.2
#19 0x00007ffff64dcf89 in xmlParseEntityRef () from /usr/lib/libxml2.so.2
#20 0x00007ffff64e8b3f in xmlParseReference () from /usr/lib/libxml2.so.2
#21 0x00007ffff64e6c28 in xmlParseContent () from /usr/lib/libxml2.so.2
#22 0x00007ffff64e675b in xmlParseElement () from /usr/lib/libxml2.so.2
#23 0x00007ffff64ed81a in xmlParseDocument () from /usr/lib/libxml2.so.2
#24 0x00007ffff64edb05 in ?? () from /usr/lib/libxml2.so.2
#25 0x00007ffff6cb0223 in
__pyx_f_4lxml_5etree_11_BaseParser__parseDocFromFile
(__pyx_v_self=0x7ffff5bf7478, __pyx_v_c_filename=0x7ffff7f5e094
"diveintopython.xml")
     at src/lxml/lxml.etree.c:71908