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The view builder builds a view by going over the entire token ring, consuming the base table partitions, and generating view updates for each partition. A view is considered as built when we complete a full cycle of the token ring. Suppose we start to build a view at a token F. We will consume all partitions with tokens starting at F until the maximum token, then go back to the minimum token and consume all partitions until F, and then we detect that we pass F and complete building the view. This happens in the view builder consumer in `check_for_built_views`. The problem is that we check if we pass the first token F with the condition `_step.current_token() >= it->first_token` whenever we consume a new partition or the current_token goes back to the minimum token. But suppose that we don't have any partitions with a token greater than or equal to the first token (this could happen if the partition with token F was moved to another node for example), then this condition will never be satisfied, and we don't detect correctly when we pass F. Instead, we go back to the minimum token, building the same token ranges again, in a possibly infinite loop. To fix this we add another step when reaching the end of the reader's stream. When this happens it means we don't have any more fragments to consume until the end of the range, so we advance the current_token to the end of the range, simulating a partition, and check for built views in that range. Fixes scylladb/scylladb#21829 Closes scylladb/scylladb#22493