melib: return Result with error when an IO operation fails

Don't unwrap anything because this might be temporary, for example a
short IMAP disconnection.

7 files changed, 144 insertions, 48 deletions

diff --git a/melib/src/email.rs b/melib/src/email.rs
index ca69f928..39a4439e 100644
--- a/melib/src/email.rs
+++ b/melib/src/email.rs
@@ -376,16 +376,18 @@ impl Envelope {
         let _strings: Vec<String> = self.to.iter().map(|a| format!("{}", a)).collect();
         _strings.join(", ")
     }
-    pub fn bytes(&self, mut operation: Box<dyn BackendOp>) -> Vec<u8> {
-        operation
-            .as_bytes()
-            .map(|v| v.into())
-            .unwrap_or_else(|_| Vec::new())
+
+    /// Requests bytes from backend and thus can fail
+    pub fn bytes(&self, mut operation: Box<dyn BackendOp>) -> Result<Vec<u8>> {
+        operation.as_bytes().map(|v| v.to_vec())
     }
+
     pub fn body_bytes(&self, bytes: &[u8]) -> Attachment {
         let builder = AttachmentBuilder::new(bytes);
         builder.build()
     }
+
+    /// Requests bytes from backend and thus can fail
     pub fn headers<'a>(&self, bytes: &'a [u8]) -> Result<Vec<(&'a str, &'a str)>> {
         let ret = parser::headers(bytes).to_full_result()?;
         let len = ret.len();
@@ -397,34 +399,14 @@ impl Envelope {
                 })
             })
     }
-    pub fn body(&self, mut operation: Box<dyn BackendOp>) -> Attachment {
+
+    /// Requests bytes from backend and thus can fail
+    pub fn body(&self, mut operation: Box<dyn BackendOp>) -> Result<Attachment> {
         debug!("searching body for {:?}", self.message_id_display());
-        let file = operation.as_bytes();
-        self.body_bytes(file.unwrap())
-        /*
-        let (headers, body) = match parser::mail(file.unwrap()).to_full_result() {
-            Ok(v) => v,
-            Err(_) => {
-            debug!("2error in parsing mail\n");
-                let error_msg = b"Mail cannot be shown because of errors.";
-                let mut builder = AttachmentBuilder::new(error_msg);
-                return builder.build();
-            }
-        };
-        let mut builder = AttachmentBuilder::new(body);
-        for (name, value) in headers {
-            if value.len() == 1 && value.is_empty() {
-                continue;
-            }
-            if name.eq_ignore_ascii_case(b"content-transfer-encoding") {
-                builder.content_transfer_encoding(value);
-            } else if name.eq_ignore_ascii_case(b"content-type") {
-                builder.content_type(value);
-            }
-        }
-        builder.build()
-        */
+        let file = operation.as_bytes()?;
+        Ok(self.body_bytes(file))
     }
+
     pub fn subject(&self) -> Cow<str> {
         match self.subject {
             Some(ref s) => String::from_utf8_lossy(s),
diff --git a/melib/src/email/compose.rs b/melib/src/email/compose.rs
index 29a62e45..17b6c16a 100644
--- a/melib/src/email/compose.rs
+++ b/melib/src/email/compose.rs
@@ -113,7 +113,7 @@ impl str::FromStr for Draft {
 }
 
 impl Draft {
-    pub fn edit(envelope: &Envelope, mut op: Box<dyn BackendOp>) -> Self {
+    pub fn edit(envelope: &Envelope, mut op: Box<dyn BackendOp>) -> Result<Self> {
         let mut ret = Draft::default();
         //TODO: Inform user if error
         {
@@ -128,10 +128,11 @@ impl Draft {
             }
         }
 
-        ret.body = envelope.body(op).text();
+        ret.body = envelope.body(op)?.text();
 
-        ret
+        Ok(ret)
     }
+
     pub fn set_header(&mut self, header: &str, value: String) {
         if self.headers.insert(header.to_string(), value).is_none() {
             self.header_order.push(header.to_string());
diff --git a/ui/src/components/mail/compose.rs b/ui/src/components/mail/compose.rs
index 3f6da8eb..6c268772 100644
--- a/ui/src/components/mail/compose.rs
+++ b/ui/src/components/mail/compose.rs
@@ -128,15 +128,15 @@ impl Composer {
      * msg: index of message we reply to in thread_nodes
      * context: current context
      */
-    pub fn edit(account_pos: usize, h: EnvelopeHash, context: &Context) -> Self {
+    pub fn edit(account_pos: usize, h: EnvelopeHash, context: &Context) -> Result<Self> {
         let mut ret = Composer::default();
         let op = context.accounts[account_pos].operation(h);
         let envelope: &Envelope = context.accounts[account_pos].get_env(&h);
 
-        ret.draft = Draft::edit(envelope, op);
+        ret.draft = Draft::edit(envelope, op)?;
 
         ret.account_cursor = account_pos;
-        ret
+        Ok(ret)
     }
     pub fn with_context(
         coordinates: (usize, usize, usize),
diff --git a/ui/src/components/mail/listing/compact.rs b/ui/src/components/mail/listing/compact.rs
index ecbec4ad..3aef9145 100644
--- a/ui/src/components/mail/listing/compact.rs
+++ b/ui/src/components/mail/listing/compact.rs
@@ -352,6 +352,7 @@ impl ListingTrait for CompactListing {
         }
         self.filter_term.clear();
 
+        let mut error: Option<(EnvelopeHash, MeliError)> = None;
         for (i, h) in self.order.keys().enumerate() {
             let account = &context.accounts[self.cursor_pos.0];
             let envelope = &account.collection[h];
@@ -367,8 +368,14 @@ impl ListingTrait for CompactListing {
                 self.selection.insert(*h, false);
                 continue;
             }
-            let op = account.operation(*h);
-            let body = envelope.body(op);
+            let op = account.operation(env_hash);
+            let body = match envelope.body(op) {
+                Ok(b) => b,
+                Err(e) => {
+                    error = Some((env_hash, e));
+                    break;
+                }
+            };
             let decoded = decode_rec(&body, None);
             let body_text = String::from_utf8_lossy(&decoded);
             if body_text.contains(&filter_term) {
@@ -377,22 +384,45 @@ impl ListingTrait for CompactListing {
                 self.selection.insert(*h, false);
             }
         }
-        if !self.filtered_selection.is_empty() {
+
+        if let Some((env_hash, error)) = error {
+            self.length = 0;
+            let message = format!("Error: {}", error.to_string());
+            log(
+                format!(
+                    "Failed to open envelope {}: {}",
+                    context.accounts[self.new_cursor_pos.0]
+                        .get_env(&env_hash)
+                        .message_id_display(),
+                    error.to_string()
+                ),
+                ERROR,
+            );
+            self.data_columns.columns[0] = CellBuffer::new(message.len(), 1, Cell::with_char(' '));
+            write_string_to_grid(
+                &message,
+                &mut self.data_columns.columns[0],
+                Color::Default,
+                Color::Default,
+                Attr::Default,
+                ((0, 0), (message.len() - 1, 0)),
+                false,
+            );
+        } else if !self.filtered_selection.is_empty() {
             self.filter_term = filter_term.to_string();
             self.cursor_pos.2 = std::cmp::min(self.filtered_selection.len() - 1, self.cursor_pos.2);
             self.length = self.filtered_selection.len();
         } else {
             self.length = 0;
             let message = format!("No results for `{}`.", filter_term);
-            self.data_columns.columns[0] =
-                CellBuffer::new(message.len(), self.length + 1, Cell::with_char(' '));
+            self.data_columns.columns[0] = CellBuffer::new(message.len(), 1, Cell::with_char(' '));
             write_string_to_grid(
                 &message,
                 &mut self.data_columns.columns[0],
                 Color::Default,
                 Color::Default,
                 Attr::Default,
-                ((0, 0), (MAX_COLS - 1, 0)),
+                ((0, 0), (message.len() - 1, 0)),
                 false,
             );
         }
diff --git a/ui/src/components/mail/listing/conversations.rs b/ui/src/components/mail/listing/conversations.rs
index 716f0882..f40c3583 100644
--- a/ui/src/components/mail/listing/conversations.rs
+++ b/ui/src/components/mail/listing/conversations.rs
@@ -417,7 +417,13 @@ impl ListingTrait for ConversationsListing {
                 continue;
             }
             let op = account.operation(env_hash);
-            let body = envelope.body(op);
+            let body = match envelope.body(op) {
+                Ok(b) => b,
+                Err(e) => {
+                    error = Some(e);
+                    break;
+                }
+            };
             let decoded = decode_rec(&body, None);
             let body_text = String::from_utf8_lossy(&decoded);
             if body_text.contains(&filter_term) {
diff --git a/ui/src/components/mail/view.rs b/ui/src/components/mail/view.rs
index cd256f6c..529d8799 100644
--- a/ui/src/components/mail/view.rs
+++ b/ui/src/components/mail/view.rs
@@ -597,7 +597,25 @@ impl Component for MailView {
                 let account = &mut context.accounts[self.coordinates.0];
                 let envelope: &Envelope = &account.get_env(&self.coordinates.2);
                 let op = account.operation(envelope.hash());
-                envelope.body(op)
+                match envelope.body(op) {
+                    Ok(body) => body,
+                    Err(e) => {
+                        context.replies.push_back(UIEvent::Notification(
+                            Some("Failed to open e-mail".to_string()),
+                            e.to_string(),
+                            Some(NotificationType::ERROR),
+                        ));
+                        log(
+                            format!(
+                                "Failed to open envelope {}: {}",
+                                envelope.message_id_display(),
+                                e.to_string()
+                            ),
+                            ERROR,
+                        );
+                        return;
+                    }
+                }
             };
             match self.mode {
                 ViewMode::Attachment(aidx) if body.attachments()[aidx].is_html() => {
@@ -799,7 +817,27 @@ impl Component for MailView {
                     let account = &mut context.accounts[self.coordinates.0];
                     let envelope: &Envelope = &account.get_env(&self.coordinates.2);
                     let op = account.operation(envelope.hash());
-                    if let Some(u) = envelope.body(op).attachments().get(lidx) {
+
+                    let attachments = match envelope.body(op) {
+                        Ok(body) => body.attachments(),
+                        Err(e) => {
+                            context.replies.push_back(UIEvent::Notification(
+                                Some("Failed to open e-mail".to_string()),
+                                e.to_string(),
+                                Some(NotificationType::ERROR),
+                            ));
+                            log(
+                                format!(
+                                    "Failed to open envelope {}: {}",
+                                    envelope.message_id_display(),
+                                    e.to_string()
+                                ),
+                                ERROR,
+                            );
+                            return true;
+                        }
+                    };
+                    if let Some(u) = attachments.get(lidx) {
                         match u.content_type() {
                             ContentType::MessageRfc822 => {
                                 match EnvelopeWrapper::new(u.body().to_vec()) {
@@ -910,7 +948,25 @@ impl Component for MailView {
                     let envelope: &Envelope = &account.get_env(&self.coordinates.2);
                     let finder = LinkFinder::new();
                     let op = account.operation(envelope.hash());
-                    let t = envelope.body(op).text().to_string();
+                    let t = match envelope.body(op) {
+                        Ok(body) => body.text().to_string(),
+                        Err(e) => {
+                            context.replies.push_back(UIEvent::Notification(
+                                Some("Failed to open e-mail".to_string()),
+                                e.to_string(),
+                                Some(NotificationType::ERROR),
+                            ));
+                            log(
+                                format!(
+                                    "Failed to open envelope {}: {}",
+                                    envelope.message_id_display(),
+                                    e.to_string()
+                                ),
+                                ERROR,
+                            );
+                            return true;
+                        }
+                    };
                     let links: Vec<Link> = finder.links(&t).collect();
                     if let Some(u) = links.get(lidx) {
                         u.as_str().to_string()
diff --git a/ui/src/components/utilities.rs b/ui/src/components/utilities.rs
index 8fa94552..02711fbe 100644
--- a/ui/src/components/utilities.rs
+++ b/ui/src/components/utilities.rs
@@ -1455,7 +1455,28 @@ impl Component for Tabbed {
                 return true;
             }
             UIEvent::Action(Tab(Edit(account_pos, msg))) => {
-                self.add_component(Box::new(Composer::edit(account_pos, msg, context)));
+                let composer = match Composer::edit(account_pos, msg, context) {
+                    Ok(c) => c,
+                    Err(e) => {
+                        context.replies.push_back(UIEvent::Notification(
+                            Some("Failed to open e-mail".to_string()),
+                            e.to_string(),
+                            Some(NotificationType::ERROR),
+                        ));
+                        log(
+                            format!(
+                                "Failed to open envelope {}: {}",
+                                context.accounts[account_pos]
+                                    .get_env(&msg)
+                                    .message_id_display(),
+                                e.to_string()
+                            ),
+                            ERROR,
+                        );
+                        return true;
+                    }
+                };
+                self.add_component(Box::new(composer));
                 self.cursor_pos = self.children.len() - 1;
                 self.children[self.cursor_pos].set_dirty();
                 return true;