improve transaction cancellation

src/daemon.vala

@@ -398,6 +398,11 @@ namespace Pamac {
 				emit_event (0, 0, {});
 				databases_lock_mutex.lock ();
 			}
+			if (cancellable.is_cancelled ()) {
+				databases_lock_mutex.unlock ();
+				cancellable.reset ();
+				return;
+			}
 			write_log_file ("synchronizing package lists");
 			current_error = ErrorInfos ();
 			int force = (force_refresh) ? 1 : 0;
@@ -1335,6 +1340,11 @@ namespace Pamac {
 				emit_event (0, 0, {});
 				databases_lock_mutex.lock ();
 			}
+			if (cancellable.is_cancelled ()) {
+				databases_lock_mutex.unlock ();
+				cancellable.reset ();
+				return false;
+			}
 			current_error = ErrorInfos ();
 			cancellable.reset ();
 			if (alpm_handle.trans_init (flags) == -1) {
@@ -1353,7 +1363,11 @@ namespace Pamac {
 		private void sysupgrade_prepare () {
 			current_error = ErrorInfos ();
 			if (!trans_init (0)) {
-				trans_prepare_finished (false);
+				if (cancellable.is_cancelled ()) {
+					trans_prepare_finished (true);
+				} else {
+					trans_prepare_finished (false);
+				}
 				return;
 			}
 			add_ignorepkgs ();
@@ -1610,7 +1624,11 @@ namespace Pamac {
 					trans_prepare_finished (false);
 				}
 			} else {
-				trans_prepare_finished (false);
+				if (cancellable.is_cancelled ()) {
+					trans_prepare_finished (true);
+				} else {
+					trans_prepare_finished (false);
+				}
 			}
 		}
 

src/transaction.vala

@@ -997,6 +997,7 @@ namespace Pamac {
 					action = dgettext (null, "Checking dependencies") + "...";
 					break;
 				case 3: //Alpm.Event.Type.FILECONFLICTS_START
+					start_transaction ();
 					action = dgettext (null, "Checking file conflicts") + "...";
 					break;
 				case 5: //Alpm.Event.Type.RESOLVEDEPS_START
@@ -1105,6 +1106,7 @@ namespace Pamac {
 				case 41: //Alpm.Event.Type.HOOK_START
 					switch (secondary_event) {
 						case 1: //Alpm.HookWhen.PRE_TRANSACTION
+							start_transaction ();
 							action = dgettext (null, "Running pre-transaction hooks") + "...";
 							break;
 						case 2: //Alpm.HookWhen.POST_TRANSACTION