Index: tests/filters.php
===================================================================
--- tests/filters.php	(revision 930)
+++ tests/filters.php	(working copy)
@@ -240,4 +240,24 @@
 		$this->assertFalse( empty($args[0][1]->foo) );
 
 	}
+
+	function _self_removal($tag) {
+		remove_action( $tag, array(&$this, '_self_removal'), 10, 1 );
+		return $tag;
+	}
+
+	function test_filter_removal_during_filter() {
+		$tag = rand_str();
+		$a = new MockAction();
+		$b = new MockAction();
+
+		add_action( $tag, array(&$a, 'filter_append'), 11, 1 );
+		add_action( $tag, array(&$b, 'filter_append'), 12, 1 );
+		add_action( $tag, array(&$this, '_self_removal'), 10, 1 );
+
+		$result = apply_filters($tag, $tag);
+		$this->assertEquals( 1, $a->get_call_count(), 'priority 11 filters should run after priority 10 empties itself' );
+		$this->assertEquals( 1, $b->get_call_count(), 'priority 12 filters should run after priority 10 empties itself and priority 11 runs' );
+		$this->assertEquals( $result, $tag . '_append_append', 'priority 11 and 12 filters should run after priority 10 empties itself' );
+	}
 }