Give up looking up interned names if the encoding changed during parsing

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 3408 matching lines @@
                     return(NULL);
                 c = CUR_CHAR(l);
             }
         }
     }
     if ((len > XML_MAX_NAME_LENGTH) &&
         ((ctxt->options & XML_PARSE_HUGE) == 0)) {
         xmlFatalErr(ctxt, XML_ERR_NAME_TOO_LONG, "Name");
         return(NULL);
     }
-    if ((*ctxt->input->cur == '\n') && (ctxt->input->cur[-1] == '\r'))
+    if ((*ctxt->input->cur == '\n') && (ctxt->input->cur[-1] == '\r')) {
+        if (ctxt->input->base > ctxt->input->cur - (len + 1)) {
+            return(NULL);
+        }
         return(xmlDictLookup(ctxt->dict, ctxt->input->cur - (len + 1), len));
+    }
+    if (ctxt->input->base > ctxt->input->cur - len) {
+        return(NULL);
+    }
     return(xmlDictLookup(ctxt->dict, ctxt->input->cur - len, len));
 }
 
 /**
  * xmlParseName:
  * @ctxt:  an XML parser context
  *
  * parse an XML name.
  *
  * [4] NameChar ::= Letter | Digit | '.' | '-' | '_' | ':' |
@@ skipping 12384 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"