Don't skip creator lines in Extra in fromJSON

Regression in 3de54455f6

chrome/content/zotero/xpcom/data/item.js

@@ -4212,6 +4212,8 @@ Zotero.Item.prototype.fromJSON = function (json, options = {}) {
 		json.extra !== undefined ? json.extra : '',
 		this,
 		Object.keys(json)
+			// TEMP until we move creator lines to real creators
+			.concat('creators')
 	);
 	
 	// Transfer valid fields from Extra to regular fields

chrome/content/zotero/xpcom/utilities_internal.js

@@ -1050,7 +1050,7 @@ Zotero.Utilities.Internal = {
 			}
 			
 			let possibleCreatorType = creatorTypes.get(key);
-			if (possibleCreatorType) {
+			if (possibleCreatorType && !additionalFields.has('creators')) {
 				let c = {
 					creatorType: possibleCreatorType
 				};

test/tests/itemTest.js

@@ -1811,6 +1811,17 @@ describe("Zotero.Item", function () {
 			assert.equal(item.getField('extra'), `doi: ${doi2}`);
 		});*/
 		
+		it("should ignore creator field in Extra", async function () {
+			var json = {
+				itemType: "journalArticle",
+				extra: "Author: Name"
+			};
+			var item = new Zotero.Item();
+			item.fromJSON(json);
+			assert.lengthOf(item.getCreatorsJSON(), 0);
+			assert.equal(item.getField('extra'), json.extra);
+		});
+		
 		it("should store unknown fields in Extra in non-strict mode", function () {
 			var json = {
 				itemType: "journalArticle",