[geary/wip/789924-network-transition-redux: 11/11] Minor MinimalFolder cleanup.

[Michael Gratton <mjog src gnome org>]

commit a6c7da4ffed5405ebdfaea11e02d18007c777109
Author: Michael James Gratton <mike vee net>
Date:   Mon Feb 5 21:12:53 2018 +1100

    Minor MinimalFolder cleanup.
    
    * src/engine/imap-engine/imap-engine-minimal-folder.vala (MinimalFolder):
      Split up on_update_flags into a synchronous callback and async
      implementation method, pass a copy of open_cancellable to it so it's
      always using the same cancellable instance and check for errors on
      completion.

 .../imap-engine/imap-engine-minimal-folder.vala    |   27 +++++++++++++++----
 1 files changed, 21 insertions(+), 6 deletions(-)
---
diff --git a/src/engine/imap-engine/imap-engine-minimal-folder.vala 
b/src/engine/imap-engine/imap-engine-minimal-folder.vala
index 4c31e94..3180a72 100644
--- a/src/engine/imap-engine/imap-engine-minimal-folder.vala
+++ b/src/engine/imap-engine/imap-engine-minimal-folder.vala
@@ -146,7 +146,7 @@ private class Geary.ImapEngine.MinimalFolder : Geary.Folder, Geary.FolderSupport
         );
 
         this.update_flags_timer = new TimeoutManager.seconds(
-            FLAG_UPDATE_TIMEOUT_SEC, () => { on_update_flags.begin(); }
+            FLAG_UPDATE_TIMEOUT_SEC, on_update_flags
         );
 
         this.refresh_unseen_timer = new TimeoutManager.seconds(
@@ -1412,18 +1412,18 @@ private class Geary.ImapEngine.MinimalFolder : Geary.Folder, Geary.FolderSupport
     /**
      * Checks for changes to {@link EmailFlags} after a folder opens.
      */
-    private async void on_update_flags() throws Error {
+    private async void update_flags(Cancellable cancellable) throws Error {
         // Update this to use CHANGEDSINCE FETCH when available, when
         // we support IMAP CONDSTORE (Bug 713117).
         int chunk_size = FLAG_UPDATE_START_CHUNK;
         Geary.EmailIdentifier? lowest = null;
         for (;;) {
-            yield wait_for_remote_async(this.open_cancellable);
+            yield wait_for_remote_async(cancellable);
             Gee.List<Geary.Email>? list_local = yield list_email_by_id_async(
                 lowest, chunk_size,
                 Geary.Email.Field.FLAGS,
                 Geary.Folder.ListFlags.LOCAL_ONLY,
-                this.open_cancellable
+                cancellable
             );
             if (list_local == null || list_local.is_empty)
                 break;
@@ -1444,7 +1444,7 @@ private class Geary.ImapEngine.MinimalFolder : Geary.Folder, Geary.FolderSupport
                 local_map.keys,
                 Email.Field.FLAGS,
                 Geary.Folder.ListFlags.FORCE_UPDATE,
-                this.open_cancellable
+                cancellable
             );
             if (list_remote == null || list_remote.is_empty)
                 break;
@@ -1460,7 +1460,7 @@ private class Geary.ImapEngine.MinimalFolder : Geary.Folder, Geary.FolderSupport
                     changed_map.set(e.id, e.email_flags);
             }
 
-            if (!this.open_cancellable.is_cancelled() && changed_map.size > 0)
+            if (!cancellable.is_cancelled() && changed_map.size > 0)
                 notify_email_flags_changed(changed_map);
 
             chunk_size *= 2;
@@ -1481,6 +1481,21 @@ private class Geary.ImapEngine.MinimalFolder : Geary.Folder, Geary.FolderSupport
         }
     }
 
+    private void on_update_flags() {
+        this.update_flags.begin(
+            this.open_cancellable,
+            (obj, res) => {
+                try {
+                    this.update_flags.end(res);
+                } catch (IOError.CANCELLED err) {
+                    // all good
+                } catch (Error err) {
+                    debug("Error updating flags: %s", err.message);
+                }
+            }
+        );
+    }
+
     private void on_remote_ready() {
         this.open_remote_session.begin();
     }