Comment 0 for bug 1471029

Running the Samba autobuild tests on a 15.04 openstack image results in a segfault in this command:

/usr/bin/xsltproc --nonet -o default/docs-xml/manpages/smb.conf.5 /home/ubuntu/autobuild/b22271/samba/docs-xml/xslt/man.xsl default/docs-xml/manpages/smb.conf.5.xml

I reported this upstream as a bug in xsltproc, but it was found to be impossible to reproduce using upstream source on the openstack instance:

https://bugzilla.gnome.org/show_bug.cgi?id=751764

Comment 8 (https://bugzilla.gnome.org/show_bug.cgi?id=751764#c8) is particularly informative.

The stack trace below shows the segfault actually occurs in libxml's xpath evaluation functions. I see no difference between xpath.c in upstream 2.9.2 and Ubuntu's version.

(gdb) bt 12
#0 0xb760f874 in xmlXPathCompOpEval (ctxt=0xba25d3e8, op=0xb86bc818) at ../../xpath.c:13606
#1 0xb760f82e in xmlXPathCompOpEval (ctxt=0xba25d3e8, op=0xb86bc890) at ../../xpath.c:13598
#2 0xb7610244 in xmlXPathCompOpEval (ctxt=0xba25d3e8, op=0xb86bc8b8) at ../../xpath.c:13529
#3 0xb760f9d6 in xmlXPathCompOpEval (ctxt=0xba25d3e8, op=0xb86bc8e0) at ../../xpath.c:13977
#4 0xb7612735 in xmlXPathCompOpEval (op=<optimized out>, ctxt=0xba25d3e8) at ../../xpath.c:14552
#5 xmlXPathRunEval (ctxt=0xba25d3e8, toBool=<optimized out>) at ../../xpath.c:14552
#6 0xb76171ed in xmlXPathCompiledEvalInternal (toBool=0, resObj=<synthetic pointer>, ctxt=<optimized out>, comp=<optimized out>) at ../../xpath.c:14915
#7 xmlXPathCompiledEval__internal_alias (comp=0xb866a948, ctx=0xb99bd308) at ../../xpath.c:14978
#8 0xb7787260 in xsltEvalVariable (ctxt=ctxt@entry=0xb9836560, variable=variable@entry=0xba25d3b0, castedComp=0xb86a4238) at ../../../libxslt/variables.c:903
#9 0xb778759a in xsltBuildVariable (ctxt=0xb9836560, castedComp=0xb86a4238, tree=0xb86a6978) at ../../../libxslt/variables.c:1759
#10 0xb7788bfa in xsltParseStylesheetCallerParam (ctxt=0xb86a6978, inst=0xb86a6978) at ../../../libxslt/variables.c:1975
#11 0xb779b9db in xsltCallTemplate (ctxt=0xb9836560, node=0xb85efed8, inst=0xb86a6880, castedComp=0xb86a4148) at ../../../libxslt/transform.c:4739
(More stack frames follow...)

(gdb) bt -5
#3311 0xb779a7de in xsltProcessOneNode (ctxt=0xb9836560, contextNode=0xb97586a0, withParams=0x0) at ../../../libxslt/transform.c:2097
#3312 0xb779d818 in xsltApplyStylesheetInternal (style=0xba25d3e8, style@entry=0xb85ee200, doc=0xb86bc7f0, doc@entry=0xb97586a0, params=0xb77ed340 <params>,
    output=0xb85e13e0 "default/docs-xml/manpages/smb.conf.5", profile=0x0, userCtxt=0xb9836560) at ../../../libxslt/transform.c:6159
#3313 0xb779df8d in xsltRunStylesheetUser (style=0xb85ee200, doc=0xb97586a0, params=0xb77ed340 <params>, output=0xb85e13e0 "default/docs-xml/manpages/smb.conf.5", SAX=0x0, IObuf=0x0,
    profile=0x0, userCtxt=0xb9836560) at ../../../libxslt/transform.c:6449
#3314 0xb77ea12c in xsltProcess (doc=0xb97586a0, cur=0xb85ee200, filename=0xbfd59812 "default/docs-xml/manpages/smb.conf.5.xml") at ../../../xsltproc/xsltproc.c:483
#3315 0xb77e9298 in main (argc=6, argv=0xbfd58f94) at ../../../xsltproc/xsltproc.c:903