make setup_handle_if_needed async, call it ahead of select_folder and fetch_new_messages (renamed from fetch_from_single_folder), and be more eager triggering reconnect on error conditions

src/imap/mod.rs

@@ -201,8 +201,7 @@ impl Imap {
         self.should_reconnect.store(true, Ordering::Relaxed)
     }
 
-    fn setup_handle_if_needed(&self, context: &Context) -> Result<()> {
-        task::block_on(async move {
+    async fn setup_handle_if_needed(&self, context: &Context) -> Result<()> {
         if self.config.read().await.imap_server.is_empty() {
             return Err(Error::InTeardown);
         }
@@ -254,9 +253,7 @@ impl Imap {
                 if (server_flags & DC_LP_AUTH_OAUTH2) != 0 {
                     let addr: &str = config.addr.as_ref();
 
-                        if let Some(token) =
-                            dc_get_oauth2_access_token(context, addr, imap_pw, true)
-                        {
+                    if let Some(token) = dc_get_oauth2_access_token(context, addr, imap_pw, true) {
                         let auth = OAuth2 {
                             user: imap_user.into(),
                             access_token: token,
@@ -295,8 +292,7 @@ impl Imap {
             }
             Err((err, _)) => {
                 let imap_user = self.config.read().await.imap_user.to_owned();
-                    let message =
-                        context.stock_string_repl_str(StockMessage::CannotLogin, &imap_user);
+                let message = context.stock_string_repl_str(StockMessage::CannotLogin, &imap_user);
 
                 emit_event!(
                     context,
@@ -306,7 +302,6 @@ impl Imap {
                 Err(Error::LoginFailed(format!("cannot login as {}", imap_user)))
             }
         }
-        })
     }
 
     async fn unsetup_handle(&self, context: &Context) {
@@ -387,7 +382,7 @@ impl Imap {
                 config.server_flags = server_flags;
             }
 
-            if let Err(err) = self.setup_handle_if_needed(context) {
+            if let Err(err) = self.setup_handle_if_needed(context).await {
                 warn!(context, "failed to setup imap handle: {}", err);
                 self.free_connect_params().await;
                 return false;
@@ -449,10 +444,9 @@ impl Imap {
                 // probably shutdown
                 return Err(Error::InTeardown);
             }
-            while self
-                .fetch_from_single_folder(context, &watch_folder)
-                .await?
-            {
+            self.setup_handle_if_needed(context).await?;
+
+            while self.fetch_new_messages(context, &watch_folder).await? {
                 // We fetch until no more new messages are there.
             }
             Ok(())
@@ -560,7 +554,7 @@ impl Imap {
         })
     }
 
-    async fn fetch_from_single_folder<S: AsRef<str>>(
+    async fn fetch_new_messages<S: AsRef<str>>(
         &self,
         context: &Context,
         folder: S,
@@ -593,9 +587,11 @@ impl Imap {
         for msg in &list {
             let cur_uid = msg.uid.unwrap_or_default();
             if cur_uid <= last_seen_uid {
-                warn!(
+                // seems that at least dovecot sends the last available UID
+                // even if we asked for higher UID+N:*
+                info!(
                     context,
-                    "unexpected uid {}, last seen was {}", cur_uid, last_seen_uid
+                    "fetch_new_messages: ignoring uid {}, last seen was {}", cur_uid, last_seen_uid
                 );
                 continue;
             }
@@ -740,7 +736,7 @@ impl Imap {
                 return Err(Error::IdleAbilityMissing);
             }
 
-            self.setup_handle_if_needed(context)?;
+            self.setup_handle_if_needed(context).await?;
 
             self.select_folder(context, watch_folder.clone()).await?;
 
@@ -886,9 +882,9 @@ impl Imap {
                     // will not find any new.
 
                     if let Some(ref watch_folder) = watch_folder {
-                        match self.fetch_from_single_folder(context, watch_folder).await {
+                        match self.fetch_new_messages(context, watch_folder).await {
                             Ok(res) => {
-                                info!(context, "fetch_from_single_folder returned {:?}", res);
+                                info!(context, "fetch_new_messages returned {:?}", res);
                                 if res {
                                     break;
                                 }
@@ -1322,13 +1318,17 @@ impl Imap {
         task::block_on(async move {
             info!(context, "emptying folder {}", folder);
 
+            // we want to report all error to the user
+            // (no retry should be attempted)
             if folder.is_empty() {
                 error!(context, "cannot perform empty, folder not set");
                 return;
             }
+            if let Err(err) = self.setup_handle_if_needed(context).await {
+                error!(context, "could not setup imap connection: {:?}", err);
+                return;
+            }
             if let Err(err) = self.select_folder(context, Some(&folder)).await {
-                // we want to report all error to the user
-                // (no retry should be attempted)
                 error!(
                     context,
                     "Could not select {} for expunging: {:?}", folder, err

src/imap/select_folder.rs

@@ -34,6 +34,7 @@ impl Imap {
             let mut cfg = self.config.write().await;
             cfg.selected_folder = None;
             cfg.selected_folder_needs_expunge = false;
+            self.trigger_reconnect();
             return Err(Error::NoSession);
         }
 
@@ -61,6 +62,7 @@ impl Imap {
                             info!(context, "close/expunge succeeded");
                         }
                         Err(err) => {
+                            self.trigger_reconnect();
                             return Err(Error::CloseExpungeFailed(err));
                         }
                     }