check for backend-returned fatal errors in major callbacks

feedlist.js

@@ -33,6 +33,7 @@ function viewCategory(cat) {
 function feedlist_callback2(transport) {
 	try {
 		debug("feedlist_callback2");
+		if (!transport_error_check(transport)) return;
 		var f = document.getElementById("feeds-frame");
 		f.innerHTML = transport.responseText;
 		feedlist_init();

functions.js

@@ -605,23 +605,7 @@ function parse_counters_reply(transport, scheduled_call) {
 		return;
 	} 
 
-	var error_code = false;
-	var error_msg = false;
-
-	if (reply.firstChild) {
-		error_code = reply.firstChild.getAttribute("error-code");
-		error_msg = reply.firstChild.getAttribute("error-msg");
-	}
-
-	if (!error_code) {	
-		error_code = reply.getAttribute("error-code");
-		error_msg = reply.getAttribute("error-msg");
-	}
-	
-	if (error_code && error_code != 0) {
-		debug("refetch_callback: got error code " + error_code);
-		return fatalError(error_code, error_msg);
-	}
+	if (!transport_error_check(transport)) return;
 
 	var counters = reply.getElementsByTagName("counters")[0];
 	
@@ -2104,4 +2088,23 @@ function browseFeeds(limit) {
 	}
 }
 
+function transport_error_check(transport) {
+	try {
+		if (transport.responseXML) {
+			var error = transport.responseXML.getElementsByTagName("error")[0];
+
+			if (error) {
+				var code = error.getAttribute("error-code");
+				var msg = error.getAttribute("error-msg");
+				if (code != 0) {
+					fatalError(code, msg);
+					return false;
+				}
+			}
+		}
+	} catch (e) {
+		exception_error("check_for_error_xml", e);
+	}
+	return true;
+}
 

viewfeed.js

@@ -67,6 +67,8 @@ function headlines_callback2(transport, feed_cur_page) {
 
 		debug("headlines_callback2 [page=" + feed_cur_page + "]");
 
+		if (!transport_error_check(transport)) return;
+
 		clean_feed_selections();
 	
 		var is_cat = false;
@@ -327,6 +329,8 @@ function article_callback2(transport, id, feed_id) {
 
 		if (transport.responseXML) {
 
+			if (!transport_error_check(transport)) return;
+
 			debug("looking for articles to cache...");
 
 			var articles = transport.responseXML.getElementsByTagName("article");