Insert the error message block when stopping parsing and an error occurred

Source/core/xml/parser/XMLDocumentParser.cpp

Index: Source/core/xml/parser/XMLDocumentParser.cpp
diff --git a/Source/core/xml/parser/XMLDocumentParser.cpp b/Source/core/xml/parser/XMLDocumentParser.cpp
index 2e5fd031092d9b9d1f4d5045e757a87dedce55fe..f80d85faa6b0c9f08581154c72687bcdeb14e73b 100644
--- a/Source/core/xml/parser/XMLDocumentParser.cpp
+++ b/Source/core/xml/parser/XMLDocumentParser.cpp
@@ -424,7 +424,9 @@ void XMLDocumentParser::end()
     if (m_parserPaused)
         return;
 
-    if (m_sawError) {
+    // stopParsing() calls insertErrorMessageBlock() if there was a parsing
+    // error. Avoid showing the error message block twice.
+    if (m_sawError && !isStopped()) {
         insertErrorMessageBlock();
     } else {
         exitText();
@@ -1553,6 +1555,8 @@ TextPosition XMLDocumentParser::textPosition() const
 
 void XMLDocumentParser::stopParsing()
 {
+    if (m_sawError)
+        insertErrorMessageBlock();
     DocumentParser::stopParsing();
     if (context())
         xmlStopParser(context());