--- a/parser/html/nsHtml5StreamParser.cpp
+++ b/parser/html/nsHtml5StreamParser.cpp
@@ -933,27 +933,27 @@ nsHtml5StreamParser::OnStartRequest(nsIR
     mInitialEncodingWasFromParentFrame = true;
   }
 
   if (mCharsetSource >= kCharsetFromAutoDetection) {
     mFeedChardet = false;
   }
   
   nsCOMPtr<nsIWyciwygChannel> wyciwygChannel(do_QueryInterface(mRequest));
-  if (wyciwygChannel) {
-    mReparseForbidden = true;
-    mFeedChardet = false;
-    // If we are reloading a document.open()ed doc, fall through to converter
-    // instantiation here and avoid BOM sniffing.
-  } else if (mCharsetSource < kCharsetFromParentForced) {
+  if (!wyciwygChannel) {
     // we aren't ready to commit to an encoding yet
     // leave converter uninstantiated for now
     return NS_OK;
   }
-  
+
+  // We are reloading a document.open()ed doc.
+  mReparseForbidden = true;
+  mFeedChardet = false;
+
+  // Instantiate the converter here to avoid BOM sniffing.
   nsCOMPtr<nsICharsetConverterManager> convManager = do_GetService(NS_CHARSETCONVERTERMANAGER_CONTRACTID, &rv);
   NS_ENSURE_SUCCESS(rv, rv);
   rv = convManager->GetUnicodeDecoder(mCharset.get(), getter_AddRefs(mUnicodeDecoder));
   // if we failed to get a decoder, there will be fallback, so don't propagate
   //  the error.
   if (NS_FAILED(rv)) {
     mCharsetSource = kCharsetFromWeakDocTypeDefault;
   }

--- a/parser/nsCharsetSource.h
+++ b/parser/nsCharsetSource.h
@@ -14,15 +14,13 @@
 #define kCharsetFromParentFrame         5
 #define kCharsetFromAutoDetection       6
 #define kCharsetFromHintPrevDoc         7
 #define kCharsetFromMetaPrescan         8 // this one and smaller: HTML5 Tentative
 #define kCharsetFromMetaTag             9 // this one and greater: HTML5 Confident
 #define kCharsetFromIrreversibleAutoDetection 10
 #define kCharsetFromChannel            11
 #define kCharsetFromOtherComponent     12
-#define kCharsetFromByteOrderMark      13
-// Levels below here will be forced onto childframes too
-#define kCharsetFromParentForced       14
-#define kCharsetFromUserForced         15
-#define kCharsetFromPreviousLoading    16
+#define kCharsetFromParentForced       13 // propagates to child frames
+#define kCharsetFromUserForced         14 // propagates to child frames
+#define kCharsetFromByteOrderMark      15
 
 #endif /* nsCharsetSource_h_ */