Resolve "Segfault on exit"

Closes #50 (closed)

src/database/queue.c

@@ -293,7 +293,8 @@ database_queue_del_id(volatile sqlite3 *db, int id)
 {
     static const char *SQL_TEMPLATE =
         "BEGIN TRANSACTION;"
-        "CREATE TEMPORARY TABLE queue_tmp (position INTEGER, kara_id INTEGER, priority INTEGER);"
+        "CREATE TEMPORARY TABLE IF NOT EXISTS queue_tmp (position INTEGER, kara_id INTEGER, priority INTEGER);"
+        "DELETE FROM queue_tmp;"
         /* Move the current 'pointer' */
         "UPDATE queue_state SET current = (SELECT NULLIF(COUNT(position), 0) FROM queue JOIN queue_state ON position <= current AND kara_id != %d);"
         "DELETE FROM queue WHERE kara_id = %d;"                                                 /* Delete any kara with the specified id */
@@ -301,7 +302,6 @@ database_queue_del_id(volatile sqlite3 *db, int id)
         "DELETE FROM queue;"
         "INSERT INTO queue(priority, position, kara_id) SELECT priority, ROW_NUMBER() OVER(ORDER BY position ASC), kara_id FROM queue_tmp;"
         "UPDATE sqlite_sequence SET seq = (SELECT COUNT(*) FROM queue) WHERE name = 'queue';"   /* Update the sqlite_sequence            */
-        "DROP TABLE queue_tmp;"                                                                 /* Erase queue_tmp                       */
         "COMMIT;";
     char SQL[LKT_MAX_SQLITE_STATEMENT];
     safe_snprintf(SQL, LKT_MAX_SQLITE_STATEMENT, SQL_TEMPLATE, id, id);