Re: [PATCH v2 6/6] last-modified: keep per-path Bloom filters for wildcard pathspecs

[Junio C Hamano <gitster@pobox.com>]

Toon Claes <toon@iotcl.com> writes:

> The last-modified builtin expands the pathspec to a set of literal paths
> and builds a Bloom key for each. During the walk it looks those keys up
> in the commit's filter to decide whether the commit is worth diffing.
> These lookups need `bloom_filter_settings` for the key hashing.
>
> prepare_revision_walk() runs prepare_to_use_bloom_filter() to build the
> pathspec key vectors. For a pathspec that cannot be turned into a Bloom
> key, such as a top-level wildcard like "*.c", that function gives up and
> clears `bloom_filter_settings`.
>
> Restore `bloom_filter_settings` after prepare_revision_walk() so the
> per-path check keeps working for wildcard pathspecs.

Should a new test or two cover a case where a pathspec with a
top-level wildcard is supplied, and ensure that this restoration
kicks in?

The machinery should work correctly with or without Bloom filters.
Without trace instrumentation, such a test might not exhibit any
behavior difference even when the filter is not restored.
However, the failure scenario is specific enough to make a good
test case.

Thanks.