Bug 1097499 part 3 - Add a separate anonbox for text nodes. r=heycam

MozReview-Commit-ID: 1GfoFEGhyka

layout/style/nsCSSParser.cpp

@@ -35,6 +35,7 @@
 #include "nsColor.h"
 #include "nsCSSPseudoClasses.h"
 #include "nsCSSPseudoElements.h"
+#include "nsCSSAnonBoxes.h"
 #include "nsNameSpaceManager.h"
 #include "nsXMLNameSpaceMap.h"
 #include "nsError.h"
@@ -5927,6 +5928,13 @@ CSSParserImpl::ParsePseudoSelector(int32_t&       aDataMask,
     return eSelectorParsingStatus_Error;
   }
 
+  if (nsCSSAnonBoxes::IsNonElement(pseudo)) {
+    // Non-element anonymous boxes should not match any rule.
+    REPORT_UNEXPECTED_TOKEN(PEPseudoSelUnknown);
+    UngetToken();
+    return eSelectorParsingStatus_Error;
+  }
+
   // We currently allow :-moz-placeholder and ::-moz-placeholder. We have to
   // be a bit stricter regarding the pseudo-element parsing rules.
   if (pseudoElementType == CSSPseudoElementType::mozPlaceholder &&