imap: Fix potential hang/crash when unhibernating

This fixes two potential bugs: a) Unhibernation is triggered by new mailbox changes. While sending these to IMAP client, Dovecot notices that the client has disconnected. The process will stay IDLEing for 30 minutes until it gets disconnected with "Disconnected: Inactivity - no input for 1800 secs" b) Unhibernation is triggered by DONE command with some further pipelined commands. During unhibernation new mailbox changes are noticed, and again IMAP client is found to be disconnected while sending the changes. This causes a segfault.
dovecot · Oct 14, 2024 · 9561790 · 9561790
1 parent 5f66f3f
commit 9561790
Showing 1 changed file with 4 additions and 2 deletions.
diff --git a/src/imap/cmd-idle.c b/src/imap/cmd-idle.c
@@ -302,7 +302,9 @@ bool cmd_idle(struct client_command_context *cmd)
 
 	/* check immediately if there are changes. if they came before we
 	   added mailbox-notifier, we wouldn't see them otherwise. */
-	if (client->mailbox != NULL)
-		idle_sync_now(client->mailbox, ctx);
+	if (client->mailbox != NULL) {
+		if (idle_sync_now(client->mailbox, ctx))
+			return TRUE;
+	}
 	return idle_client_handle_input(ctx, FALSE);
 }