Update libxml to 2.7.7.

third_party/libxml/schematron.c

 /*
  * schematron.c : implementation of the Schematron schema validity checking
  *
  * See Copyright for the status of this software.
  *
  * Daniel Veillard <daniel@veillard.com>
  */
 
 /*
  * TODO:
@@ skipping 1407 matching lines @@
             data = ctxt->userData;
         }
 
         __xmlRaiseError(schannel, channel, data,
                         NULL, cur, XML_FROM_SCHEMATRONV,
                         (test->type == XML_SCHEMATRON_ASSERT)?XML_SCHEMATRONV_ASSERT:XML_SCHEMATRONV_REPORT,
                         XML_ERR_ERROR, NULL, line,
                         (pattern == NULL)?NULL:((const char *) pattern->name),
                         (const char *) path,
                         (const char *) report, 0, 0,
-                        msg);
+                        "%s", msg);
     } else {
         xmlSchematronReportOutput(ctxt, cur, &msg[0]);
     }
 
     xmlFree((char *) report);
 
         if ((path != NULL) && (path != (xmlChar *) cur->name))
             xmlFree(path);
     }
 }
@@ skipping 245 matching lines @@
          * we are just trying to assert the validity of the document,
          * speed primes over the output, run in a single pass
          */
         cur = root;
         while (cur != NULL) {
             rule = ctxt->schema->rules;
             while (rule != NULL) {
                 if (xmlPatternMatch(rule->pattern, cur) == 1) {
                     test = rule->tests;
                     while (test != NULL) {
-                        xmlSchematronRunTest(ctxt, test, instance, cur, rule->pattern);
+                        xmlSchematronRunTest(ctxt, test, instance, cur, (xmlSchematronPatternPtr)rule->pattern);
                         test = test->next;
                     }
                 }
                 rule = rule->next;
             }
             
             cur = xmlSchematronNextNode(cur);
         }
     } else {
         /*
@@ skipping 71 matching lines @@
 
     xmlCleanupParser();
     xmlMemoryDump();
 
     return (0);
 }
 #endif
 #define bottom_schematron
 #include "elfgcchack.h"
 #endif /* LIBXML_SCHEMATRON_ENABLED */