Re: [PATCH] rev-list-options: fix off-by-one in '--filter=blob:limit=<n>' explainer

"Nikolay Edigaryev via GitGitGadget" [off-list ref]
writes:

From: Nikolay Edigaryev <redacted>

'--filter=blob:limit=<n>' was introduced in 25ec7bcac0 (list-objects:
filter objects in traverse_commit_list, 2017-11-21) and later expanded
to bitmaps in 84243da129 (pack-bitmap: implement BLOB_LIMIT filtering,
2020-02-14)

The logic that was introduced in these commits (and that still persists
to this day) omits blobs larger than _or equal_ to n bytes or units.

Good eyes.  The former does this

		if (object_length < filter_data->max_bytes)
			goto include_it;

and the latter does this


                if (!bitmap_get(tips, pos) &&
                    get_size_by_pos(bitmap_git, pos) >= limit)
                        bitmap_unset(to_filter, pos);

However, the documentation (Documentation/rev-list-options.txt) states:

quoted

The form '--filter=blob:limit=<n>[kmg]' omits blobs larger than n

bytes or units. n may be zero.

Moreover, the t6113-rev-list-bitmap-filters.sh tests for exactly this
logic, so it seems it is the documentation that needs fixing, not the
code.

Yup.  The mechanism is used for things like "we do not want a large
blob, like 100MB", and a byte on the boundary does not matter all
that much in such a countext, but it does not hurt to be more
correct ;-)

 The form '--filter=blob:none' omits all blobs.
 +
-The form '--filter=blob:limit=<n>[kmg]' omits blobs larger than n bytes
-or units.  n may be zero.  The suffixes k, m, and g can be used to name
-units in KiB, MiB, or GiB.  For example, 'blob:limit=1k' is the same
-as 'blob:limit=1024'.
+The form '--filter=blob:limit=<n>[kmg]' omits blobs of size at least n
+bytes or units.  n may be zero.  The suffixes k, m, and g can be used
+to name units in KiB, MiB, or GiB.  For example, 'blob:limit=1k'
+is the same as 'blob:limit=1024'.

With unnecessary paragraph wrapping, it is a bit hard to compare the
preimage and the postimage, but I manually checked that this only
does

	"larger than" -> "of size at least"

and nothing else, which is expected and in line with what the
proposed commit message claimed to do.  Good job.

Will queue.  Thanks.

 +
 The form '--filter=object:type=(tag|commit|tree|blob)' omits all objects
 which are not of the requested type.

base-commit: 564d0252ca632e0264ed670534a51d18a689ef5d