Agent crash in packet match

[Hari Prasad Killi]

Core was generated by `/usr/bin/contrail-vrouter-agent'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007fb34fed9479 in std::string::assign(std::string const&) ()
   from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#0 0x00007fb34fed9479 in std::string::assign(std::string const&) ()
   from /usr/lib/x86_64-linux-gnu/libstdc++.so.6
#1 0x0000000000d8332f in AddressMatch::Match(PacketHeader const*, FlowPolicyInfo*) const ()
#2 0x0000000000d8168a in AclEntry::PacketMatch(PacketHeader const&, FlowPolicyInfo*) const ()
#3 0x0000000000d7e242 in AclDBEntry::PacketMatch(PacketHeader const&, MatchAclParams&, FlowPolicyInfo*) const ()
#4 0x0000000000c31f57 in PktFlowInfo::VrfTranslate(PktInfo const*, PktControlInfo*, PktControlInfo*, boost::asio::ip::address const&, bool) ()
#5 0x0000000000c32c18 in PktFlowInfo::IngressProcess(PktInfo const*, PktControlInfo*, PktControlInfo*) ()
#6 0x0000000000c336d4 in PktFlowInfo::Process(PktInfo const*, PktControlInfo*, PktControlInfo*) ()
#7 0x0000000000c3e676 in FlowHandler::Run() ()
#8 0x0000000000c3abe8 in Proto::ProcessProto(boost::shared_ptr<PktInfo>) ()
#9 0x0000000000c24a8f in FlowProto::FlowEventHandler(FlowEvent const&, FlowTable*) ()

[OpenContrail Admin (ci-admin-f)]

Review in progress for https://review.opencontrail.org/16358
Submitter: Hari Prasad Killi (<email address hidden>)

[OpenContrail Admin (ci-admin-f)]

Reviewed: https://review.opencontrail.org/16358
Committed: http://github.org/Juniper/contrail-controller/commit/9865510d739c4c505e333791c20d60b4d6934b3c
Submitter: Zuul
Branch: master

commit 9865510d739c4c505e333791c20d60b4d6934b3c
Author: Hari <email address hidden>
Date: Tue Jan 19 10:28:30 2016 +0530

Add NULL check

While doing address match, update flow policy info only when required.

Change-Id: Ib4b275c42e1455bc5bd341cfcbaefb488efa6dc3
closes-bug: 1535528