Rework DB transaction handling

Rollback callbacks weren't being properly called, and some other things were in
the wrong place, particularly with nested transactions.

chrome/content/zotero/xpcom/db.js

@@ -465,6 +465,15 @@ Zotero.DBConnection.prototype.executeTransaction = Zotero.Promise.coroutine(func
 				}
 			}
 			
+			try {
+				var result = yield Zotero.Promise.coroutine(func)();
+			}
+			catch (e) {
+				Zotero.debug("Rolled back nested async DB transaction", 5);
+				this._asyncTransactionNestingLevel = 0;
+				throw e;
+			}
+			
 			Zotero.debug("Decreasing async DB transaction level to "
 				+ --this._asyncTransactionNestingLevel, 5);
 			return result;
@@ -489,7 +498,6 @@ Zotero.DBConnection.prototype.executeTransaction = Zotero.Promise.coroutine(func
 				}
 			}
 			var result = yield conn.executeTransaction(func);
-			try {
 			Zotero.debug("Committed async DB transaction", 5);
 			
 			// Clear transaction time
@@ -528,11 +536,11 @@ Zotero.DBConnection.prototype.executeTransaction = Zotero.Promise.coroutine(func
 			
 			return result;
 		}
+	}
 	catch (e) {
 		Zotero.debug("Rolled back async DB transaction", 5);
 		Zotero.debug(e, 1);
 		
-				try {
 		if (options) {
 			// Function to run once transaction has been committed but before any
 			// permanent callbacks
@@ -553,15 +561,15 @@ Zotero.DBConnection.prototype.executeTransaction = Zotero.Promise.coroutine(func
 				yield Zotero.Promise.resolve(this._callbacks.rollback[i]());
 			}
 		}
-				}
+		
-				finally {
+		if (reject) {
-					setTimeout(reject, 0);
+			setTimeout(function () {
+				reject(e);
+			}, 0);
 		}
 		
 		throw e;
 	}
-		}
-	}
 	finally {
 		// Reset options back to their previous values
 		if (options) {

test/tests/dbTest.js

@@ -0,0 +1,83 @@
+describe("Zotero.DB", function() {
+	describe("#executeTransaction()", function () {
+		it("should roll back on error", function* () {
+			yield Zotero.DB.queryAsync("CREATE TABLE tmpRollbackOnError (foo INT)");
+			yield Zotero.DB.queryAsync("INSERT INTO tmpRollbackOnError VALUES (1)");
+			try {
+				yield Zotero.DB.executeTransaction(function* () {
+					yield Zotero.DB.queryAsync("INSERT INTO tmpRollbackOnError VALUES (2)");
+					throw 'Aborting transaction -- ignore';
+				});
+			}
+			catch (e) {
+				if (typeof e != 'string' || !e.startsWith('Aborting transaction')) throw e;
+			}
+			var count = yield Zotero.DB.valueQueryAsync("SELECT COUNT(*) FROM tmpRollbackOnError");
+			assert.equal(count, 1);
+			
+			var conn = yield Zotero.DB._getConnectionAsync();
+			assert.isFalse(conn.transactionInProgress);
+			
+			yield Zotero.DB.queryAsync("DROP TABLE tmpRollbackOnError");
+		});
+		
+		it("should run onRollback callbacks", function* () {
+			var callbackRan = false;
+			yield Zotero.DB.queryAsync("CREATE TABLE tmpOnRollback (foo INT)");
+			try {
+				yield Zotero.DB.executeTransaction(
+					function* () {
+						yield Zotero.DB.queryAsync("INSERT INTO tmpOnRollback VALUES (1)");
+						throw 'Aborting transaction -- ignore';
+					},
+					{
+						onRollback: function () {
+							callbackRan = true;
+						}
+					}
+				);
+			}
+			catch (e) {
+				if (typeof e != 'string' || !e.startsWith('Aborting transaction')) throw e;
+			}
+			assert.ok(callbackRan);
+			
+			yield Zotero.DB.queryAsync("DROP TABLE tmpOnRollback");
+		});
+		
+		it("should run onRollback callbacks for nested transactions", function* () {
+			var callback1Ran = false;
+			var callback2Ran = false;
+			yield Zotero.DB.queryAsync("CREATE TABLE tmpOnNestedRollback (foo INT)");
+			try {
+				yield Zotero.DB.executeTransaction(function* () {
+					yield Zotero.DB.queryAsync("INSERT INTO tmpOnNestedRollback VALUES (1)");
+					yield Zotero.DB.executeTransaction(
+						function* () {
+							yield Zotero.DB.queryAsync("INSERT INTO tmpOnNestedRollback VALUES (2)");
+							
+							throw 'Aborting transaction -- ignore';
+						},
+						{
+							onRollback: function () {
+								callback1Ran = true;
+							}
+						}
+					);
+				},
+				{
+					onRollback: function () {
+						callback2Ran = true;
+					}
+				});
+			}
+			catch (e) {
+				if (typeof e != 'string' || !e.startsWith('Aborting transaction')) throw e;
+			}
+			assert.ok(callback1Ran);
+			assert.ok(callback2Ran);
+			
+			yield Zotero.DB.queryAsync("DROP TABLE tmpOnNestedRollback");
+		});
+	})
+});