Desist libxml from continuing the parse after a SAX callback has stopped the

third_party/libxml/src/parser.c

 /*
  * parser.c : an XML 1.0 parser, namespaces and validity support are mostly
  *            implemented on top of the SAX interfaces
  *
  * References:
  *   The XML specification:
  *     http://www.w3.org/TR/REC-xml
  *   Original 1.0 version:
  *     http://www.w3.org/TR/1998/REC-xml-19980210
  *   XML second edition working draft
@@ skipping 4809 matching lines @@
                 }
                 SKIP(2);
 
                 /*
                  * SAX: PI detected.
                  */
                 if ((ctxt->sax) && (!ctxt->disableSAX) &&
                     (ctxt->sax->processingInstruction != NULL))
                     ctxt->sax->processingInstruction(ctxt->userData,
                                                      target, NULL);
-                ctxt->instate = state;
+                if (ctxt->instate != XML_PARSER_EOF)
+                    ctxt->instate = state;
                 return;
             }
             buf = (xmlChar *) xmlMallocAtomic(size * sizeof(xmlChar));
             if (buf == NULL) {
                 xmlErrMemory(ctxt, NULL);
                 ctxt->instate = state;
                 return;
             }
             cur = CUR;
             if (!IS_BLANK(cur)) {
@@ skipping 59 matching lines @@
                  */
                 if ((ctxt->sax) && (!ctxt->disableSAX) &&
                     (ctxt->sax->processingInstruction != NULL))
                     ctxt->sax->processingInstruction(ctxt->userData,
                                                      target, buf);
             }
             xmlFree(buf);
         } else {
             xmlFatalErr(ctxt, XML_ERR_PI_NOT_STARTED, NULL);
         }
-        ctxt->instate = state;
+        if (ctxt->instate != XML_PARSER_EOF)
+            ctxt->instate = state;
     }
 }
 
 /**
  * xmlParseNotationDecl:
  * @ctxt:  an XML parser context
  *
  * parse a notation declaration
  *
  * [82] NotationDecl ::= '<!NOTATION' S Name S (ExternalID |  PublicID) S? '>'
@@ skipping 4538 matching lines @@
 
     line = ctxt->input->line;
 #ifdef LIBXML_SAX1_ENABLED
     if (ctxt->sax2)
 #endif /* LIBXML_SAX1_ENABLED */
         name = xmlParseStartTag2(ctxt, &prefix, &URI, &tlen);
 #ifdef LIBXML_SAX1_ENABLED
     else
         name = xmlParseStartTag(ctxt);
 #endif /* LIBXML_SAX1_ENABLED */
+    if (ctxt->instate == XML_PARSER_EOF)
+        return;
     if (name == NULL) {
         spacePop(ctxt);
         return;
     }
     namePush(ctxt, name);
     ret = ctxt->node;
 
 #ifdef LIBXML_VALID_ENABLED
     /*
      * [ VC: Root Element Type ]
@@ skipping 1359 matching lines @@
                 else
                     spacePush(ctxt, *ctxt->space);
 #ifdef LIBXML_SAX1_ENABLED
                 if (ctxt->sax2)
 #endif /* LIBXML_SAX1_ENABLED */
                     name = xmlParseStartTag2(ctxt, &prefix, &URI, &tlen);
 #ifdef LIBXML_SAX1_ENABLED
                 else
                     name = xmlParseStartTag(ctxt);
 #endif /* LIBXML_SAX1_ENABLED */
+                if (ctxt->instate == XML_PARSER_EOF)
+                    goto done;
                 if (name == NULL) {
                     spacePop(ctxt);
                     ctxt->instate = XML_PARSER_EOF;
                     if ((ctxt->sax) && (ctxt->sax->endDocument != NULL))
                         ctxt->sax->endDocument(ctxt->userData);
                     goto done;
                 }
 #ifdef LIBXML_VALID_ENABLED
                 /*
                  * [ VC: Root Element Type ]
@@ skipping 166 matching lines @@
                     xmlParseEndTag2(ctxt,
                            (void *) ctxt->pushTab[ctxt->nameNr * 3 - 3],
                            (void *) ctxt->pushTab[ctxt->nameNr * 3 - 2], 0,
                        (int) (long) ctxt->pushTab[ctxt->nameNr * 3 - 1], 0);
                     nameNsPop(ctxt);
                 }
 #ifdef LIBXML_SAX1_ENABLED
                   else
                     xmlParseEndTag1(ctxt, 0);
 #endif /* LIBXML_SAX1_ENABLED */
-                if (ctxt->nameNr == 0) {
+                if (ctxt->instate == XML_PARSER_EOF) {
+                    /* Nothing */
+                } else if (ctxt->nameNr == 0) {
                     ctxt->instate = XML_PARSER_EPILOG;
                 } else {
                     ctxt->instate = XML_PARSER_CONTENT;
                 }
                 break;
             case XML_PARSER_CDATA_SECTION: {
                 /*
                  * The Push mode need to have the SAX callback for 
                  * cdataBlock merge back contiguous callbacks.
                  */
@@ skipping 3805 matching lines @@
     if (stream == NULL) {
         xmlFreeParserInputBuffer(input);
         return (NULL);
     }
     inputPush(ctxt, stream);
     return (xmlDoRead(ctxt, URL, encoding, options, 1));
 }
 
 #define bottom_parser
 #include "elfgcchack.h"