Do not bomb out on unusual xml

In particular, properly handle directy Type child of XRD element.

As usually, thanks to Joseph Smarr of Plaxo for spotting it ;-)

Signed-off-by: Michael Krelin <hacker@klever.net>

1 files changed, 26 insertions, 15 deletions

diff --git a/lib/discovery.cc b/lib/discovery.cc
index cbdceb3..f8a3988 100644
--- a/lib/discovery.cc
+++ b/lib/discovery.cc
@@ -409,115 +409,126 @@ namespace opkele {
                                 }else
                                     ++a;
                             }
                         }else if(is_qelement(n,NSURI_XRD "\tExpires")) {
                             assert(xrd);
                             cdata_buf.clear();
                             cdata = &cdata_buf;
                         }else if(xmode&xmode_html) {
                             html_start_element(n,a);
                         }else{
                             skipping = 1;
                         }
                     }else if(pt_s==2) {
                         if(is_qelement(pt_stack.back().c_str(), NSURI_XRD "\tService")) {
                             if(is_qelement(n,NSURI_XRD "\tType")) {
                                 assert(xrd); assert(xrd_service);
                                 cdata_buf.clear();
                                 cdata = &cdata_buf;
                             }else if(is_qelement(n,NSURI_XRD "\tURI")) {
                                 assert(xrd); assert(xrd_service);
                                 const char *append = element_attr(a,"append");
                                 xrd::uri_t& uri = xrd_service->uris.add(element_priority(a),xrd::uri_t("",append?append:""));
                                 cdata = &uri.uri;
                             }else if(is_qelement(n,NSURI_XRD "\tLocalID")
                                     || is_qelement(n,NSURI_OPENID10 "\tDelegate") ) {
                                 assert(xrd); assert(xrd_service);
                                 cdata = &(xrd_service->local_ids.add(element_priority(a),string()));
                             }else if(is_qelement(n,NSURI_XRD "\tProviderID")) {
                                     assert(xrd); assert(xrd_service);
                                     cdata = &(xrd_service->provider_id);
                             }else{
                                 skipping = 1;
                             }
                         }else
                             skipping = 1;
                     }else if(xmode&xmode_html) {
                         html_start_element(n,a);
                     }else{
                         skipping = 1;
                     }
                 }
             }
             void end_element(const XML_Char *n) {
                 if(skipping<0) return;
                 if(skipping) {
                     --skipping; return;
                 }
                 if(is_qelement(n,NSURI_XRD "\tType")) {
-                    assert(xrd); assert(xrd_service); assert(cdata==&cdata_buf);
-                    xrd_service->types.insert(cdata_buf);
+                    if(xrd && xrd_service) {
+                        assert(cdata==&cdata_buf);
+                        xrd_service->types.insert(cdata_buf);
+                    }
                 }else if(is_qelement(n,NSURI_XRD "\tService")) {
-                    assert(xrd); assert(xrd_service);
-                    assert(!pt_stack.empty());
-                    assert(pt_stack.back()==(NSURI_XRD "\tService"));
-                    pt_stack.pop_back();
-                    xrd_service = 0;
-                }else if(is_qelement(n,NSURI_XRD "\tStatus")) {
-                    assert(xrd);
-                    if(is_qelement(pt_stack.back().c_str(),n)) {
-                        assert(cdata==&status_string);
+                    if(!(xrd && xrd_service)) {
+                        skipping = -1;
+                    }else{
+                        assert(!pt_stack.empty());
+                        assert(pt_stack.back()==(NSURI_XRD "\tService"));
                         pt_stack.pop_back();
-                        if(status_code!=100)
-                            skipping = -1;
+                        xrd_service = 0;
+                    }
+                }else if(is_qelement(n,NSURI_XRD "\tStatus")) {
+                    if(!xrd) {
+                        skipping=-1;
+                    }else{
+                        if(is_qelement(pt_stack.back().c_str(),n)) {
+                            assert(cdata==&status_string);
+                            pt_stack.pop_back();
+                            if(status_code!=100)
+                                skipping = -1;
+                        }
                     }
                 }else if(is_qelement(n,NSURI_XRD "\tExpires")) {
-                    assert(xrd);
-                    xrd->expires = util::w3c_to_time(cdata_buf);
+                    if(!xrd) {
+                        skipping=-1;
+                    }else{
+                        xrd->expires = util::w3c_to_time(cdata_buf);
+                    }
                 }else if((xmode&xmode_html) && is_element(n,"head")) {
                     skipping = -1;
                 }
                 cdata = 0;
             }
             void character_data(const XML_Char *s,int l) {
                 if(skipping) return;
                 if(cdata) cdata->append(s,l);
             }
 
             void html_start_element(const XML_Char *n,const XML_Char **a) {
                 if(is_element(n,"meta")) {
                     bool heq = false;
                     string l;
                     for(;*a;a+=2) {
                         if(!( strcasecmp(a[0],"http-equiv")
                                 || strcasecmp(a[1],XRDS_HEADER) ))
                             heq = true;
                         else if(!strcasecmp(a[0],"content"))
                             l.assign(a[1]);
                     }
                     if(heq)
                         xrds_location = l;
                 }else if(is_element(n,"link")) {
                     string rels;
                     string href;
                     for(;*a;a+=2) {
                         if( !strcasecmp(a[0],"rel") ) {
                             rels.assign(a[1]);
                         }else if( !strcasecmp(a[0],"href") ) {
                             const char *ns = a[1];
                             for(;*ns && isspace(*ns);++ns) ;
                             href.assign(ns);
                             string::size_type lns=href.find_last_not_of(data::_whitespace_chars);
                             href.erase(lns+1);
                         }
                     }
                     for(string::size_type ns=rels.find_first_not_of(data::_whitespace_chars);
                             ns!=string::npos; ns=rels.find_first_not_of(data::_whitespace_chars,ns)) {
                         string::size_type s = rels.find_first_of(data::_whitespace_chars,ns);
                         string rel;
                         if(s==string::npos) {
                             rel.assign(rels,ns,string::npos);
                             ns = string::npos;
                         }else{
                             rel.assign(rels,ns,s-ns);
                             ns = s;
                         }