Bug 741218 - Don't crash when loading a page with content-type application/json; r=hsivonen

content/html/document/crashtests/741218.json

@@ -0,0 +1 @@
+{}

content/html/document/crashtests/741218.json^headers^

@@ -0,0 +1 @@
+Content-Type: application/json

content/html/document/crashtests/crashtests.list

@@ -13,3 +13,4 @@ load 495543.svg
 load 564461.xhtml
 load 601422.html
 load 631421.html
+load 741218.json

content/html/document/src/nsHTMLDocument.cpp

@@ -584,14 +584,15 @@ nsHTMLDocument::StartDocumentLoad(const char* aCommand,
   }
 
   bool html = contentType.EqualsLiteral(TEXT_HTML);
-  bool xhtml = !html && contentType.Equals("application/xhtml+xml");
+  bool xhtml = !html && contentType.EqualsLiteral(APPLICATION_XHTML_XML);
   bool plainText = !html && !xhtml && (contentType.EqualsLiteral(TEXT_PLAIN) ||
     contentType.EqualsLiteral(TEXT_CSS) ||
     contentType.EqualsLiteral(APPLICATION_JAVASCRIPT) ||
     contentType.EqualsLiteral(APPLICATION_XJAVASCRIPT) ||
     contentType.EqualsLiteral(TEXT_ECMASCRIPT) ||
     contentType.EqualsLiteral(APPLICATION_ECMASCRIPT) ||
-    contentType.EqualsLiteral(TEXT_JAVASCRIPT));
+    contentType.EqualsLiteral(TEXT_JAVASCRIPT) ||
+    contentType.EqualsLiteral(APPLICATION_JSON));
   if (!(html || xhtml || plainText || viewSource)) {
     MOZ_NOT_REACHED("Channel with bad content type.");
     return NS_ERROR_INVALID_ARG;