Upload: Fix the final file name collision test in wp_unique_filename() when uploading a file with upper case extension. Add a unit test to catch that in the future.

Fixes #48975 for trunk.


git-svn-id: https://develop.svn.wordpress.org/trunk@46966 602fd350-edb4-49c9-b593-d223f7449a82

tests/phpunit/tests/functions.php

@@ -208,6 +208,8 @@ class Tests_Functions extends WP_UnitTestCase {
 		// Test collision with existing sub-size filename.
 		// Existing files: one-blue-pixel-100x100.png, one-blue-pixel-1-100x100.png.
 		$this->assertEquals( 'one-blue-pixel-2.png', wp_unique_filename( $testdir, 'one-blue-pixel.png' ) );
+		// Same as above with upper case extension.
+		$this->assertEquals( 'one-blue-pixel-2.png', wp_unique_filename( $testdir, 'one-blue-pixel.PNG' ) );
 
 		remove_filter( 'upload_dir', array( $this, 'upload_dir_patch_basedir' ) );
 	}