feat: Move primary transport checked update into "remove transports" transaction

This guarantees that the primary transport is never removed while being in use. At least this way
it's obvious that there are no such corner cases.

src/transport.rs

@@ -21,6 +21,7 @@ use crate::constants::{DC_LP_AUTH_FLAGS, DC_LP_AUTH_OAUTH2};
 use crate::context::Context;
 use crate::ensure_and_debug_assert;
 use crate::events::EventType;
+use crate::log::warn;
 use crate::login_param::EnteredLoginParam;
 use crate::net::load_connection_timestamp;
 use crate::provider::{Protocol, Provider, Socket, UsernamePattern, get_provider_by_id};
@@ -774,6 +775,7 @@ pub(crate) async fn send_sync_transports(context: &Context) -> Result<()> {
 /// Process received data for transport synchronization.
 pub(crate) async fn sync_transports(
     context: &Context,
+    from_addr: &str,
     transports: &[TransportData],
     removed_transports: &[RemovedTransportData],
 ) -> Result<()> {
@@ -788,7 +790,7 @@ pub(crate) async fn sync_transports(
         modified |= save_transport(context, entered, configured, *timestamp, *is_published).await?;
     }
 
-    context
+    let primary_changed = context
         .sql
         .transaction(|transaction| {
             for RemovedTransportData { addr, timestamp } in removed_transports {
@@ -806,13 +808,43 @@ pub(crate) async fn sync_transports(
                     (addr, timestamp),
                 )?;
             }
-            Ok(())
+
+            let transport_exists = transaction.query_row(
+                "SELECT COUNT(*) FROM transports WHERE addr=?",
+                (from_addr,),
+                |row| {
+                    let count: i64 = row.get(0)?;
+                    Ok(count > 0)
+                },
+            )?;
+
+            let primary_changed = if transport_exists {
+                transaction.execute(
+                    "
+UPDATE config SET value=? WHERE keyname='configured_addr' AND value!=?1
+                    ",
+                    (from_addr,),
+                )? > 0
+            } else {
+                warn!(
+                    context,
+                    "Received sync message from unknown address {from_addr:?}."
+                );
+                false
+            };
+            Ok(primary_changed)
         })
         .await?;
 
     if modified {
-        context.self_public_key.lock().await.take();
         tokio::task::spawn(restart_io_if_running_boxed(context.clone()));
+    }
+    if primary_changed {
+        info!(context, "Primary transport changed to {from_addr:?}.");
+        context.sql.uncache_raw_config("configured_addr").await;
+    }
+    if modified || primary_changed {
+        context.self_public_key.lock().await.take();
         context.emit_event(EventType::TransportsModified);
     }
     Ok(())