Fix for bug 91450 (complete loss of style when executing a certain javascript). r=pierre, sr=jst.

content/base/src/nsStyleLinkElement.cpp

@@ -192,14 +192,27 @@ nsStyleLinkElement::UpdateStyleSheet(PRBool aNotify, nsIDocument *aOldDocument,
 
   nsCOMPtr<nsIDOMStyleSheet> styleSheet(do_QueryInterface(mStyleSheet));
 
-  if (styleSheet) {
+  if (mStyleSheet && url.IsEmpty()) {
+    // Inline stylesheets have the document's URL as their URL internally
+    nsCOMPtr<nsIURI> docURL, styleSheetURL;
+    mStyleSheet->GetURL(*getter_AddRefs(styleSheetURL));
+    doc->GetBaseURL(*getter_AddRefs(docURL));
+    if (docURL && styleSheetURL) {
+      PRBool inlineStyle;
+      docURL->Equals(styleSheetURL, &inlineStyle);
+      if (inlineStyle) {
+        return NS_OK;
+      }
+    }
+  }
+  else if (styleSheet) {
     nsAutoString oldHref;
 
     styleSheet->GetHref(oldHref);
-
-    if (oldHref.Equals(url))
+    if (oldHref.Equals(url)) {
       return NS_OK;
     }
+  }
 
   if (mStyleSheet) {
     doc->RemoveStyleSheet(mStyleSheet);