size_format() incorrectly displays `kB` with small `k`

[dashaluna]

The size_format() incorrectly displays kB unit. It should be KB.

[swissspidy]

… because 1 kB means 1000 bytes, whereas 1 KB = 1 KiB = 1024 bytes.

size_format() assumes that 1024 bytes = 1 kB, so yeah, that sounds wrong.

[pento]

Related: #31350.

I don't mind this change - traditionally, kB has been the most common usage, but it seems to have changed to KB over the years, shifting from the SI standard, where kB = 1000 bytes, to the JEDEC standard, where KB = 1024 bytes.

Switching to the IEC standard (KiB, etc) is a much bigger discussion, particularly because those units have never really seen significant uptake. (Because they look weird, and all of the units are really awkward to say.)

[dashaluna]

I feel that whatever the decision will be, it should be consistent. As we're displaying file sizes in a table with all measurements being in capitals and kB looks like an oversight.

You get something looking:

GB
MB
kB
B

Sorry for being pedantic :)

[Presskopp]

IMHO we could just keep kB, even it maybe painful for your eyes, @dashaluna :)
See Table here: ​https://en.wikipedia.org/wiki/Kilobyte

Just for the record, we see it used here:

\wp-includes\ID3\module.audio.mp3.php, L.1375

round($sync_seek_buffer_size / 1024).'kB';

and as a comment here:

\wp-includes\ID3\module.audio-video.riff.php, L.1695

		} elseif ($chunksize < 2048) {
			// only read data in if smaller than 2kB

[DrewAPicture]

@Presskopp Care to add a patch?

[Presskopp]

@DrewAPicture Why not, so you say it should be patched to KB?

If so, we also have it in

wp-includes/deprecated.php, L 3238

	$units = array( 0 => 'B', 1 => 'kB', 2 => 'MB', 3 => 'GB', 4 => 'TB' );

As it's deprecated, would this also be needed to get patched?

And what if @dashaluna wants to create a patch herself?

[DrewAPicture]

Replying to Presskopp:

@DrewAPicture Why not, so you say it should be patched to KB?

If so, we also have it in

wp-includes/deprecated.php, L 3238

	$units = array( 0 => 'B', 1 => 'kB', 2 => 'MB', 3 => 'GB', 4 => 'TB' );

As it's deprecated, would this also be needed to get patched?

And what if @dashaluna wants to create a patch herself?

Yes, let's standardize on uppercase. If either you or @dashaluna would like to generate a patch, that would be fine :-)

[lukecavanagh]

Patch for deprecated.php

[Presskopp]

kb => KB, that's all

[Presskopp]

there was a typo, missing '

[DrewAPicture]

Assigning to mark the good-first-bug as "claimed".

[ocean90]

Introduced in [5801].

@Presskopp External libraries like ID3 shouldn't be changed.

[Presskopp]

let the externals alone

[SergeyBiryukov]

In 37702:

In size_format() and wp_convert_bytes_to_hr(), replace kB with KB for consistency with other units.

Props Presskopp, dashaluna.
Fixes #37037.

[SergeyBiryukov]

In 37705:

After [37702], correct the expected result in test_size_format().

See #37037.