4.15 array_count_values wrong return type? causes DocblockTypeContradiction

[kkmuffme]

https://psalm.dev/r/97c8ae1796

Not sure what the issue is, just that it was working correctly up until at least 4.13, probably 4.14 too

[psalm-github-bot]

I found these snippets:

https://psalm.dev/r/97c8ae1796

<?php

$tokenized = preg_split( '/(?=[A-Z])|[0-9]/', '^SQP8F5s%6a1#iAl1w3@', -1, PREG_SPLIT_NO_EMPTY );
$length_count = array_map( 'strlen', $tokenized );

$occurence_count = array_count_values( $length_count );
ksort( $occurence_count );

$longest_token = array_key_last( $occurence_count );

if ( $longest_token === 1 ) {
	echo "hello";
}

Psalm output (using commit ae765df):

ERROR: DocblockTypeContradiction - 11:6 - 1 does not contain null

ERROR: DocblockTypeContradiction - 11:6 - Docblock-defined type null for $longest_token is never int(1)

[orklah]

This is caused by #7045.

I'm reading it again and the stub shouldn't return array<empty, empty> when the param is not a non-empty-array, it should return array<TKey, positive-int>

@weirdan if you have a moment, mind fixing this? Otherwise I'll do it tomorrow afternoon

[weirdan]

Indeed.