feat: Remove "jobs" from imap_markseen if folder doesn't exist (#5870)

Add a `create` param to `select_with_uidvalidity()` instead of always trying to create the folder
and return `Ok(false)` from it if the folder doesn't exist and shouldn't be created, and handle this
in `store_seen_flags_on_imap()` by just removing "jobs" from the `imap_markseen` table. Also don't
create the folder in other code paths where it's not necessary.

src/configure.rs

@@ -452,8 +452,9 @@ async fn configure(ctx: &Context, param: &EnteredLoginParam) -> Result<Configure
     imap.configure_folders(ctx, &mut imap_session, create_mvbox)
         .await?;
 
+    let create = true;
     imap_session
-        .select_with_uidvalidity(ctx, "INBOX")
+        .select_with_uidvalidity(ctx, "INBOX", create)
         .await
         .context("could not read INBOX status")?;
 

src/download.rs

@@ -3,7 +3,7 @@
 use std::cmp::max;
 use std::collections::BTreeMap;
 
-use anyhow::{anyhow, bail, Result};
+use anyhow::{anyhow, bail, ensure, Result};
 use deltachat_derive::{FromSql, ToSql};
 use serde::{Deserialize, Serialize};
 
@@ -201,7 +201,11 @@ impl Session {
             bail!("Attempt to fetch UID 0");
         }
 
-        self.select_with_uidvalidity(context, folder).await?;
+        let create = false;
+        let folder_exists = self
+            .select_with_uidvalidity(context, folder, create)
+            .await?;
+        ensure!(folder_exists, "No folder {folder}");
 
         // we are connected, and the folder is selected
         info!(context, "Downloading message {}/{} fully...", folder, uid);

src/imap.rs

@@ -13,7 +13,7 @@ use std::{
     time::{Duration, UNIX_EPOCH},
 };
 
-use anyhow::{bail, format_err, Context as _, Result};
+use anyhow::{bail, ensure, format_err, Context as _, Result};
 use async_channel::Receiver;
 use async_imap::types::{Fetch, Flag, Name, NameAttribute, UnsolicitedResponse};
 use deltachat_contact_tools::ContactAddress;
@@ -540,10 +540,14 @@ impl Imap {
             return Ok(false);
         }
 
-        session
-            .select_with_uidvalidity(context, folder)
+        let create = false;
+        let folder_exists = session
+            .select_with_uidvalidity(context, folder, create)
             .await
             .with_context(|| format!("Failed to select folder {folder:?}"))?;
+        if !folder_exists {
+            return Ok(false);
+        }
 
         if !session.new_mail && !fetch_existing_msgs {
             info!(context, "No new emails in folder {folder:?}.");
@@ -835,44 +839,51 @@ impl Session {
         folder: &str,
         folder_meaning: FolderMeaning,
     ) -> Result<()> {
+        let uid_validity;
         // Collect pairs of UID and Message-ID.
         let mut msgs = BTreeMap::new();
 
-        self.select_with_uidvalidity(context, folder).await?;
+        let create = false;
+        let folder_exists = self
+            .select_with_uidvalidity(context, folder, create)
+            .await?;
+        if folder_exists {
+            let mut list = self
+                .uid_fetch("1:*", RFC724MID_UID)
+                .await
+                .with_context(|| format!("Can't resync folder {folder}"))?;
+            while let Some(fetch) = list.try_next().await? {
+                let headers = match get_fetch_headers(&fetch) {
+                    Ok(headers) => headers,
+                    Err(err) => {
+                        warn!(context, "Failed to parse FETCH headers: {}", err);
+                        continue;
+                    }
+                };
+                let message_id = prefetch_get_message_id(&headers);
 
-        let mut list = self
-            .uid_fetch("1:*", RFC724MID_UID)
-            .await
-            .with_context(|| format!("can't resync folder {folder}"))?;
-        while let Some(fetch) = list.try_next().await? {
-            let headers = match get_fetch_headers(&fetch) {
-                Ok(headers) => headers,
-                Err(err) => {
-                    warn!(context, "Failed to parse FETCH headers: {}", err);
-                    continue;
+                if let (Some(uid), Some(rfc724_mid)) = (fetch.uid, message_id) {
+                    msgs.insert(
+                        uid,
+                        (
+                            rfc724_mid,
+                            target_folder(context, folder, folder_meaning, &headers).await?,
+                        ),
+                    );
                 }
-            };
-            let message_id = prefetch_get_message_id(&headers);
-
-            if let (Some(uid), Some(rfc724_mid)) = (fetch.uid, message_id) {
-                msgs.insert(
-                    uid,
-                    (
-                        rfc724_mid,
-                        target_folder(context, folder, folder_meaning, &headers).await?,
-                    ),
-                );
             }
-        }
 
-        info!(
-            context,
-            "Resync: collected {} message IDs in folder {}",
-            msgs.len(),
-            folder,
-        );
+            info!(
+                context,
+                "resync_folder_uids: Collected {} message IDs in {folder}.",
+                msgs.len(),
+            );
 
-        let uid_validity = get_uidvalidity(context, folder).await?;
+            uid_validity = get_uidvalidity(context, folder).await?;
+        } else {
+            warn!(context, "resync_folder_uids: No folder {folder}.");
+            uid_validity = 0;
+        }
 
         // Write collected UIDs to SQLite database.
         context
@@ -1039,7 +1050,11 @@ impl Session {
             // MOVE/DELETE operations. This does not result in multiple SELECT commands
             // being sent because `select_folder()` does nothing if the folder is already
             // selected.
-            self.select_with_uidvalidity(context, folder).await?;
+            let create = false;
+            let folder_exists = self
+                .select_with_uidvalidity(context, folder, create)
+                .await?;
+            ensure!(folder_exists, "No folder {folder}");
 
             // Empty target folder name means messages should be deleted.
             if target.is_empty() {
@@ -1133,30 +1148,40 @@ impl Session {
             .await?;
 
         for (folder, rowid_set, uid_set) in UidGrouper::from(rows) {
-            if let Err(err) = self.select_with_uidvalidity(context, &folder).await {
-                warn!(context, "store_seen_flags_on_imap: Failed to select {folder}, will retry later: {err:#}.");
+            let create = false;
+            let folder_exists = match self.select_with_uidvalidity(context, &folder, create).await {
+                Err(err) => {
+                    warn!(
+                        context,
+                        "store_seen_flags_on_imap: Failed to select {folder}, will retry later: {err:#}.");
+                    continue;
+                }
+                Ok(folder_exists) => folder_exists,
+            };
+            if !folder_exists {
+                warn!(context, "store_seen_flags_on_imap: No folder {folder}.");
             } else if let Err(err) = self.add_flag_finalized_with_set(&uid_set, "\\Seen").await {
                 warn!(
                     context,
                     "Cannot mark messages {uid_set} in {folder} as seen, will retry later: {err:#}.");
+                continue;
             } else {
                 info!(
                     context,
                     "Marked messages {} in folder {} as seen.", uid_set, folder
                 );
-                context
-                    .sql
-                    .transaction(|transaction| {
-                        let mut stmt =
-                            transaction.prepare("DELETE FROM imap_markseen WHERE id = ?")?;
-                        for rowid in rowid_set {
-                            stmt.execute((rowid,))?;
-                        }
-                        Ok(())
-                    })
-                    .await
-                    .context("Cannot remove messages marked as seen from imap_markseen table")?;
             }
+            context
+                .sql
+                .transaction(|transaction| {
+                    let mut stmt = transaction.prepare("DELETE FROM imap_markseen WHERE id = ?")?;
+                    for rowid in rowid_set {
+                        stmt.execute((rowid,))?;
+                    }
+                    Ok(())
+                })
+                .await
+                .context("Cannot remove messages marked as seen from imap_markseen table")?;
         }
 
         Ok(())
@@ -1172,9 +1197,14 @@ impl Session {
             return Ok(());
         }
 
-        self.select_with_uidvalidity(context, folder)
+        let create = false;
+        let folder_exists = self
+            .select_with_uidvalidity(context, folder, create)
             .await
-            .context("failed to select folder")?;
+            .context("Failed to select folder")?;
+        if !folder_exists {
+            return Ok(());
+        }
 
         let mailbox = self
             .selected_mailbox
@@ -1630,7 +1660,7 @@ fn format_setmetadata(folder: &str, device_token: &str) -> String {
 impl Session {
     /// Returns success if we successfully set the flag or we otherwise
     /// think add_flag should not be retried: Disconnection during setting
-    /// the flag, or other imap-errors, returns true as well.
+    /// the flag, or other imap-errors, returns Ok as well.
     ///
     /// Returning error means that the operation can be retried.
     async fn add_flag_finalized_with_set(&mut self, uid_set: &str, flag: &str) -> Result<()> {
@@ -1677,7 +1707,11 @@ impl Session {
                 self.close().await?;
                 // Before moving emails to the mvbox we need to remember its UIDVALIDITY, otherwise
                 // emails moved before that wouldn't be fetched but considered "old" instead.
-                self.select_with_uidvalidity(context, folder).await?;
+                let create = false;
+                let folder_exists = self
+                    .select_with_uidvalidity(context, folder, create)
+                    .await?;
+                ensure!(folder_exists, "No MVBOX folder {:?}??", &folder);
                 return Ok(Some(folder));
             }
         }
@@ -1688,7 +1722,10 @@ impl Session {
         // Some servers require namespace-style folder names like "INBOX.DeltaChat", so we try all
         // the variants here.
         for folder in folders {
-            match self.select_with_uidvalidity(context, folder).await {
+            match self
+                .select_with_uidvalidity(context, folder, create_mvbox)
+                .await
+            {
                 Ok(_) => {
                     info!(context, "MVBOX-folder {} created.", folder);
                     return Ok(Some(folder));
@@ -2539,10 +2576,14 @@ async fn add_all_recipients_as_contacts(
         );
         return Ok(());
     };
-    session
-        .select_with_uidvalidity(context, &mailbox)
+    let create = false;
+    let folder_exists = session
+        .select_with_uidvalidity(context, &mailbox, create)
         .await
         .with_context(|| format!("could not select {mailbox}"))?;
+    if !folder_exists {
+        return Ok(());
+    }
 
     let recipients = session
         .get_all_recipients(context)

src/imap/idle.rs

@@ -29,7 +29,9 @@ impl Session {
     ) -> Result<Self> {
         use futures::future::FutureExt;
 
-        self.select_with_uidvalidity(context, folder).await?;
+        let create = true;
+        self.select_with_uidvalidity(context, folder, create)
+            .await?;
 
         if self.drain_unsolicited_responses(context)? {
             self.new_mail = true;

src/imap/scan_folders.rs

@@ -34,6 +34,7 @@ impl Imap {
         let watched_folders = get_watched_folders(context).await?;
 
         let mut folder_configs = BTreeMap::new();
+        let mut folder_names = Vec::new();
 
         for folder in folders {
             let folder_meaning = get_folder_meaning_by_attrs(folder.attributes());
@@ -44,6 +45,7 @@ impl Imap {
                 // already been moved and left it in the inbox.
                 continue;
             }
+            folder_names.push(folder.name().to_string());
             let folder_name_meaning = get_folder_meaning_by_name(folder.name());
 
             if let Some(config) = folder_meaning.to_config() {
@@ -91,6 +93,7 @@ impl Imap {
             }
         }
 
+        info!(context, "Found folders: {folder_names:?}.");
         last_scan.replace(tools::Time::now());
         Ok(true)
     }

src/imap/select_folder.rs

@@ -111,7 +111,8 @@ impl ImapSession {
         }
     }
 
-    /// Selects a folder and takes care of UIDVALIDITY changes.
+    /// Selects a folder optionally creating it and takes care of UIDVALIDITY changes. Returns false
+    /// iff `folder` doesn't exist.
     ///
     /// When selecting a folder for the first time, sets the uid_next to the current
     /// mailbox.uid_next so that no old emails are fetched.
@@ -123,11 +124,24 @@ impl ImapSession {
         &mut self,
         context: &Context,
         folder: &str,
-    ) -> Result<()> {
-        let newly_selected = self
-            .select_or_create_folder(context, folder)
-            .await
-            .with_context(|| format!("failed to select or create folder {folder}"))?;
+        create: bool,
+    ) -> Result<bool> {
+        let newly_selected = if create {
+            self.select_or_create_folder(context, folder)
+                .await
+                .with_context(|| format!("failed to select or create folder {folder}"))?
+        } else {
+            match self.select_folder(context, folder).await {
+                Ok(newly_selected) => newly_selected,
+                Err(err) => match err {
+                    Error::NoFolder(..) => return Ok(false),
+                    _ => {
+                        return Err(err)
+                            .with_context(|| format!("failed to select folder {folder}"))?
+                    }
+                },
+            }
+        };
         let mailbox = self
             .selected_mailbox
             .as_mut()
@@ -199,7 +213,7 @@ impl ImapSession {
                 }
             }
 
-            return Ok(());
+            return Ok(true);
         }
 
         // UIDVALIDITY is modified, reset highest seen MODSEQ.
@@ -233,7 +247,7 @@ impl ImapSession {
             old_uid_next,
             old_uid_validity,
         );
-        Ok(())
+        Ok(true)
     }
 }