Bug #253807 --> mime encode the feed subject using the character set encoding of the RSS document.

This means moving nsIMimeConverter
into a scriptable interface so we can access it from JS.

Fixes several issues with the RSS extension not handling non ascii subjects.

mail/extensions/newsblog/content/Feed.js

@@ -226,6 +226,8 @@ Feed.prototype.parseAsRSS2 = function() {
     var item = new FeedItem();
     item.feed = this;
 
+    item.characterSet = this.request.responseXML.characterSet ? this.request.responseXML.characterSet : "UTF-8";
+
     var link = getNodeValue(itemNode.getElementsByTagName("link")[0]);
 
     var guidNode = itemNode.getElementsByTagName("guid")[0];
@@ -254,6 +256,10 @@ Feed.prototype.parseAsRSS2 = function() {
     if (content)
       item.content = content;
 
+    var content = getNodeValue(itemNode.getElementsByTagNameNS(RSS_CONTENT_NS, "encoded")[0]);
+    if (content)
+      item.content = content;
+
     this.itemsToStore[i] = item;
   }
   
@@ -297,6 +303,8 @@ Feed.prototype.parseAsRSS1 = function() {
     var item = new FeedItem();
     item.feed = this;
 
+    item.characterSet = this.request.responseXML.characterSet ? this.request.responseXML.characterSet : "UTF-8";
+
     // Prefer the value of the link tag to the item URI since the URI could be
     // a relative URN.
     var uri = itemResource.Value;
@@ -349,6 +357,8 @@ Feed.prototype.parseAsAtom = function() {
     var item = new FeedItem();
     item.feed = this;
 
+    item.characterSet = this.request.responseXML.characterSet ? this.request.responseXML.characterSet : "UTF-8";
+
     var url;
     var links = itemNode.getElementsByTagName("link");
     for ( var j=0 ; j<links.length ; j++ ) {

mail/extensions/newsblog/content/FeedItem.js

@@ -286,6 +286,27 @@ FeedItem.prototype.toUtf8 = function(str) {
   return FeedItem.unicodeConverter.ConvertFromUnicode(str);
 }
 
+function mimeEncodeSubject(aSubject, charset)
+{  
+  // get the mime header encoder service
+  var mimeEncoder = Components
+    .classes["@mozilla.org/messenger/mimeconverter;1"]
+    .getService(Components.interfaces.nsIMimeConverter);
+
+  // this routine sometimes throws exceptions for mis encoded data so wrap it 
+  // with a try catch for now..
+  var newSubject;
+
+  try {
+    newSubject = mimeEncoder.encodeMimePartIIStr(aSubject, false, charset, 9, 72);
+  }
+  catch (ex) { 
+    newSubject = aSubject; 
+  }
+
+  return newSubject;
+}
+
 FeedItem.prototype.writeToFolder = function() {
   debug(this.identity + " writing to message folder" + this.feed.name + "\n");
   
@@ -301,6 +322,7 @@ FeedItem.prototype.writeToFolder = function() {
 
   // Compress white space in the subject to make it look better.
   this.title = this.title.replace(/[\t\r\n]+/g, " ");
+  this.title = mimeEncodeSubject(this.title, this.characterSet);
 
   // If the date looks like it's in W3C-DTF format, convert it into
   // an IETF standard date.  Otherwise assume it's in IETF format.
@@ -329,7 +351,7 @@ FeedItem.prototype.writeToFolder = function() {
     'From: ' + this.author + '\n' +
     'MIME-Version: 1.0\n' +
     'Subject: ' + this.title + '\n' +
-    'Content-Type: text/html; charset=UTF-8\n' +
+    'Content-Type: text/html; charset=' + this.characterSet + '\n' +
     'Content-Transfer-Encoding: 8bit\n' +
     'Content-Base: ' + this.url + '\n' +
     '\n' +