mail/listing.rs: prevent list blank when refreshing account

Mail list would go blank if the currently focused account received a
Status update event.

melib/src/conf.rs

@@ -147,15 +147,15 @@ impl MailboxConf {
     }
 }
 
-pub fn true_val() -> bool {
+pub const fn true_val() -> bool {
     true
 }
 
-pub fn false_val() -> bool {
+pub const fn false_val() -> bool {
     false
 }
 
-pub fn none<T>() -> Option<T> {
+pub const fn none<T>() -> Option<T> {
     None
 }
 

src/components/mail.rs

@@ -19,8 +19,8 @@
  * along with meli. If not, see <http://www.gnu.org/licenses/>.
  */
 
-/*! Entities that handle Mail specific functions.
- */
+//! Entities that handle Mail specific functions.
+
 use melib::{
     backends::{AccountHash, Mailbox, MailboxHash},
     email::{attachment_types::*, attachments::*},

src/components/mail/listing.rs

@@ -1037,7 +1037,6 @@ impl Component for Listing {
                             },
                         })
                         .collect::<_>();
-                    self.set_dirty(true);
                     self.menu_content.empty();
                     context
                         .replies
@@ -1945,6 +1944,7 @@ impl Component for Listing {
         }
         false
     }
+
     fn is_dirty(&self) -> bool {
         self.dirty
             || self
@@ -1953,6 +1953,7 @@ impl Component for Listing {
                 .map(Component::is_dirty)
                 .unwrap_or_else(|| self.component.is_dirty())
     }
+
     fn set_dirty(&mut self, value: bool) {
         self.dirty = value;
         if let Some(s) = self.status.as_mut() {
@@ -2577,6 +2578,7 @@ impl Listing {
                         .process_event(&mut UIEvent::VisibilityChange(false), context);
                     self.component
                         .set_coordinates((account_hash, *mailbox_hash));
+                    self.component.refresh_mailbox(context, true);
                     /* Check if per-mailbox configuration overrides general configuration */
 
                     let index_style =