Ensure xmlFree(NULL) is a no-op instead of a core dump. Per report from
authorTom Lane <tgl@sss.pgh.pa.us>
Wed, 10 Jun 2009 03:44:35 +0000 (03:44 +0000)
committerTom Lane <tgl@sss.pgh.pa.us>
Wed, 10 Jun 2009 03:44:35 +0000 (03:44 +0000)
commit89f30c6ceb695571b04e9b70b8bccf725183bab4
treefa8516e97850ccf6639c7af5f225dbb65bc4b15e
parent47dbe7da1902765a70a19bd49874a8451638d692
Ensure xmlFree(NULL) is a no-op instead of a core dump.  Per report from
Sergey Burladyan, there are at least some dank corners of libxml2 that
assume this behavior, even though their published documentation suggests
they shouldn't.

This is only really a live problem in 8.3, but the code is still there
for possible debugging use in HEAD, so patch both branches.
src/backend/utils/adt/xml.c