From fbb54a762188b71dd7257460d46d05512b5d5bc8 Mon Sep 17 00:00:00 2001
From: Dan Stillman <dstillman@zotero.org>
Date: Fri, 29 Nov 2019 01:50:43 -0700
Subject: [PATCH] Fix "string is undefined" export error

Regression from a549a64de93
---
 chrome/content/zotero/xpcom/date.js |  4 +++-
 test/tests/dateTest.js              | 25 +++++++++++++++++++++++++
 2 files changed, 28 insertions(+), 1 deletion(-)

diff --git a/chrome/content/zotero/xpcom/date.js b/chrome/content/zotero/xpcom/date.js
index ec36d83a72..189ad0b790 100644
--- a/chrome/content/zotero/xpcom/date.js
+++ b/chrome/content/zotero/xpcom/date.js
@@ -263,7 +263,9 @@ Zotero.Date = new function(){
 			order: ''
 		};
 		
-		string = Zotero.Utilities.trimInternal(string.toString());
+		if (typeof string == 'string' || typeof string == 'number') {
+			string = Zotero.Utilities.trimInternal(string.toString());
+		}
 		
 		// skip empty things
 		if(!string) {
diff --git a/test/tests/dateTest.js b/test/tests/dateTest.js
index 4330f94f10..eb7eec8036 100644
--- a/test/tests/dateTest.js
+++ b/test/tests/dateTest.js
@@ -157,6 +157,31 @@ describe("Zotero.Date", function() {
 	})
 	
 	describe("#strToDate()", function () {
+		it("should return object without date parts for null", function () {
+			var o = Zotero.Date.strToDate(null);
+			assert.notProperty(o, 'year');
+		});
+		
+		it("should return object without date parts for undefined", function () {
+			var o = Zotero.Date.strToDate();
+			assert.notProperty(o, 'year');
+		});
+		
+		it("should return object without date parts for false", function () {
+			var o = Zotero.Date.strToDate(false);
+			assert.notProperty(o, 'year');
+		});
+		
+		it("should return object without date parts for empty string", function () {
+			var o = Zotero.Date.strToDate('');
+			assert.notProperty(o, 'year');
+		});
+		
+		it("should return object without date parts for blank string", function () {
+			var o = Zotero.Date.strToDate(' ');
+			assert.notProperty(o, 'year');
+		});
+		
 		it("should work in translator sandbox", function* () {
 			var item = createUnsavedDataObject('item');
 			item.libraryID = Zotero.Libraries.userLibraryID;