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

third_party/libxml/src/parser.c

Index: third_party/libxml/src/parser.c
diff --git a/third_party/libxml/src/parser.c b/third_party/libxml/src/parser.c
index e3136123dca65738b9823706c4caa3fec04f3c4a..33786f08354ddcb1c4bcdaeb9b57d313cfaeff57 100644
--- a/third_party/libxml/src/parser.c
+++ b/third_party/libxml/src/parser.c
@@ -3426,8 +3426,15 @@ xmlParseNameComplex(xmlParserCtxtPtr ctxt) {
         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));
 }