Fx60: Update DB query onRow() behavior

onRow() handlers now get passed a cancellation function as a second
argument

chrome/content/zotero/xpcom/db.js

@@ -586,22 +586,14 @@ Zotero.DBConnection.prototype.queryAsync = Zotero.Promise.coroutine(function* (s
 		}
 		var failed = false;
 		if (options && options.onRow) {
-			// Errors in onRow don't stop the query unless StopIteration is thrown
-			onRow = function (row) {
+			// Errors in onRow don't stop the query unless the 'cancel' function is called
+			onRow = function (row, cancel) {
 				try {
-					options.onRow(row);
+					options.onRow(row, cancel);
 				}
 				catch (e) {
-					// If the onRow throws a StopIteration, stop gracefully
-					if (e instanceof StopIteration) {
-						Zotero.debug("Query cancelled", 3);
-					}
-					// Otherwise, mark the promise as rejected, which Sqlite.jsm doesn't do
-					// on a StopIteration by default
-					else {
-						failed = e;
-					}
-					throw StopIteration;
+					failed = e;
+					cancel();
 				}
 			}
 		}

components/zotero-autocomplete.js

@@ -214,10 +214,11 @@ ZoteroAutoComplete.prototype.startSearch = Zotero.Promise.coroutine(function* (s
 	var onRow = null;
 	// If there's a result callback (e.g., for sorting), don't use a row handler
 	if (!resultsCallback) {
-		onRow = function (row) {
+		onRow = function (row, cancel) {
 			if (this._cancelled) {
 				Zotero.debug("Cancelling query");
-				throw StopIteration;
+				cancel();
+				return;
 			}
 			var result = row.getResultByIndex(0);
 			var comment = row.getResultByIndex(1);

test/tests/dbTest.js

@@ -151,16 +151,17 @@ describe("Zotero.DB", function() {
 			assert.equal(e.message, "Failed");
 		});
 		
-		it("should stop gracefully if onRow throws a StopIteration", function* () {
+		it("should stop gracefully if onRow calls cancel()", function* () {
 			var i = 0;
 			var rows = [];
 			yield Zotero.DB.queryAsync(
 				"SELECT * FROM " + tmpTable,
 				false,
 				{
-					onRow: function (row) {
+					onRow: function (row, cancel) {
 						if (i > 0) {
-							throw StopIteration;
+							cancel();
+							return;
 						}
 						rows.push(row.getResultByIndex(0));
 						i++;