Better error reporting when creating a folder fails (#3325)

Fixes #3310

CHANGELOG.md

@@ -8,6 +8,7 @@
 - support `source_code_url` from Webxdc manifests #3314
 - support Webxdc document names and add `document` to `dc_msg_get_webxdc_info()` #3317
 - improve chat encryption info, make it easier to find contacts without keys #3318
+- improve error reporting when creating a folder fails #3325
 
 ### API-Changes
 - deprecate unused `marker1before` argument of `dc_get_chat_msgs`

src/imap/select_folder.rs

@@ -1,6 +1,7 @@
 use super::Imap;
 
 use crate::context::Context;
+use anyhow::Context as _;
 
 type Result<T> = std::result::Result<T, Error>;
 
@@ -15,8 +16,8 @@ pub enum Error {
     #[error("IMAP Folder name invalid: {0}")]
     BadFolderName(String),
 
-    #[error("IMAP folder does not exist: {0}")]
-    NoFolder(String),
+    #[error("Got a NO response when trying to select {0}, usually this means that it doesn't exist: {1}")]
+    NoFolder(String, String),
 
     #[error("IMAP close/expunge failed")]
     CloseExpungeFailed(#[from] async_imap::error::Error),
@@ -117,8 +118,8 @@ impl Imap {
                     Err(async_imap::error::Error::Validate(_)) => {
                         Err(Error::BadFolderName(folder.to_string()))
                     }
-                    Err(async_imap::error::Error::No(_)) => {
-                        Err(Error::NoFolder(folder.to_string()))
+                    Err(async_imap::error::Error::No(response)) => {
+                        Err(Error::NoFolder(folder.to_string(), response))
                     }
                     Err(err) => {
                         self.config.selected_folder = None;
@@ -139,19 +140,19 @@ impl Imap {
         &mut self,
         context: &Context,
         folder: &str,
-    ) -> Result<NewlySelected> {
+    ) -> anyhow::Result<NewlySelected> {
         match self.select_folder(context, Some(folder)).await {
             Ok(newly_selected) => Ok(newly_selected),
             Err(err) => match err {
-                Error::NoFolder(_) => {
-                    if let Some(ref mut session) = self.session {
-                        session.create(folder).await?;
-                    } else {
-                        return Err(Error::NoSession);
-                    }
-                    self.select_folder(context, Some(folder)).await
+                Error::NoFolder(..) => {
+                    let session = self.session.as_mut().context("no IMAP session")?;
+                    session.create(folder).await.with_context(|| {
+                        format!("Couldn't select folder ('{}'), then create() failed", err)
+                    })?;
+
+                    Ok(self.select_folder(context, Some(folder)).await?)
                 }
-                _ => Err(err),
+                _ => Err(err.into()),
             },
         }
     }