fix warnings and bugs, noticed on nightly

deltachat-ffi/src/lib.rs

@@ -285,7 +285,7 @@ pub unsafe extern "C" fn dc_start_io(context: *mut dc_context_t) {
     }
     let ctx = &*context;
 
-    block_on({ ctx.start_io() })
+    block_on(ctx.start_io())
 }
 
 #[no_mangle]
@@ -295,7 +295,7 @@ pub unsafe extern "C" fn dc_is_io_running(context: *mut dc_context_t) -> libc::c
     }
     let ctx = &*context;
 
-    block_on({ ctx.is_io_running() }) as libc::c_int
+    block_on(ctx.is_io_running()) as libc::c_int
 }
 
 #[no_mangle]
@@ -1829,7 +1829,11 @@ pub unsafe extern "C" fn dc_send_locations_to_chat(
     }
     let ctx = &*context;
 
-    block_on({ location::send_locations_to_chat(&ctx, ChatId::new(chat_id), seconds as i64) });
+    block_on(location::send_locations_to_chat(
+        &ctx,
+        ChatId::new(chat_id),
+        seconds as i64,
+    ));
 }
 
 #[no_mangle]

src/imap/mod.rs

@@ -811,7 +811,6 @@ impl Imap {
                     Ok(_) => Some(server_uid),
                     Err(err) => {
                         warn!(context, "dc_receive_imf error: {}", err);
-                        read_errors += 1;
                         None
                     }
                 }

src/location.rs

@@ -530,7 +530,7 @@ pub async fn save(
             accuracy,
             ..
         } = location;
-        context
+        let (loc_id, ts) = context
             .sql
             .with_conn(move |mut conn| {
                 let mut stmt_test = conn
@@ -569,9 +569,11 @@ pub async fn save(
                         )?;
                     }
                 }
-                Ok(())
+                Ok((newest_location_id, newest_timestamp))
             })
             .await?;
+        newest_timestamp = ts;
+        newest_location_id = loc_id;
     }
 
     Ok(newest_location_id)

src/mimeparser.rs

@@ -257,7 +257,8 @@ impl MimeMessage {
                 self.parts[0].msg = "".to_string();
 
                 // swap new with old
-                std::mem::replace(&mut self.parts[0], filepart);
+                self.parts.push(filepart); // push to the end
+                let _ = self.parts.swap_remove(0); // drops first element, replacing it with the last one in O(1)
             }
         }
     }