Index: tests/phpunit/tests/post/meta.php
===================================================================
--- tests/phpunit/tests/post/meta.php	(revision 32722)
+++ tests/phpunit/tests/post/meta.php	(working copy)
@@ -243,4 +243,26 @@
 		$this->assertEquals($funky_meta, get_post_meta($this->post_id, 'test_funky_post_meta', true));
 
 	}
+
+	/**
+	 * @ticket 18210
+	 */
+	function test_case_insensitive_collation_inconsistencies() {
+		$this->assertInternalType( 'integer', add_post_meta( $this->post_id, 'ALLDAY', 'value' ) );
+		$this->assertInternalType( 'integer', add_post_meta( $this->post_id_2, 'ALLDAY', 'value' ) );
+
+		$this->assertTrue( update_post_meta( $this->post_id, 'allday', 'update using lowercase' ) );
+
+		$this->assertEquals( 'value', get_post_meta( $this->post_id, 'ALLDAY', true ) );
+		$this->assertEquals( 'update using lowercase', get_post_meta( $this->post_id, 'allday', true ) );
+
+		$posts = get_posts( 'meta_key=allday' );
+		$this->assertEquals( 1, count( $posts ) );
+
+		$this->assertTrue( delete_post_meta( $this->post_id, 'allday' ) );
+		$this->assertEquals( 'update using lowercase', get_post_meta( $this->post_id, 'ALLDAY', true ) );
+		$this->assertEquals( '', get_post_meta( $this->post_id, 'allday', true ) );
+
+
+	}
 }