From a402350cda13f6da7508b507af568b5cf66bb4a6 Mon Sep 17 00:00:00 2001
From: Simon Kornblith <simon@simonster.com>
Date: Thu, 16 Feb 2012 13:29:32 -0500
Subject: [PATCH] Better error handling in addStatement

---
 chrome/content/zotero/xpcom/translation/translate.js | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/chrome/content/zotero/xpcom/translation/translate.js b/chrome/content/zotero/xpcom/translation/translate.js
index d2f050d2b..72c1e2721 100644
--- a/chrome/content/zotero/xpcom/translation/translate.js
+++ b/chrome/content/zotero/xpcom/translation/translate.js
@@ -2155,6 +2155,16 @@ Zotero.Translate.IO._RDFSandbox.prototype = {
 	 *     (false)
 	 */
 	"addStatement":function(about, relation, value, literal) {
+		if(about === null || about === undefined) {
+			throw new Error("about must be defined in Zotero.RDF.addStatement");
+		}
+		if(relation === null || relation === undefined) {
+			throw new Error("relation must be defined in Zotero.RDF.addStatement");
+		}
+		if(value === null || value === undefined) {
+			throw new Error("value must be defined in Zotero.RDF.addStatement");
+		}
+		
 		if(literal) {
 			// zap chars that Mozilla will mangle
 			value = value.toString().replace(/[\x00-\x08\x0B\x0C\x0E-\x1F]/g, '');