File extension validation breaks after update to PHP 8.1.3 and Yii 2.0.45

[michalwoz]

What steps will reproduce the problem?

['file', 'file',
    'extensions' => ['png','jpg'],
],

What is the expected result?

Allow *.jpg and *.png

What do you get instead?

All extensions including jpg and png are considered invalid.

The problem is here:

yii2/framework/helpers/BaseFileHelper.php

Lines 165 to 167 in 1271bc4

	if (PHP_VERSION_ID >= 80100) {
	return static::getMimeTypeByExtension($file, $magicFile);
	}

The $file which is analysed in above function is the temporary file with .tmp extension on Windows and no extension (/tmp/xxxxx) on Linux. We cannot get "getMimeTypeByExtension" from it.

Adding 'checkExtensionByMimeType' => false, to validation rules solved the problem for me. Is that expected behaviour?

Additional info

Q	A
Yii version	2.0.45
PHP version	8.1.3
Operating system	Windows/Linux

[michalwoz]

Duplicate of #19307