diff --git a/src/wp-includes/plugin.php b/src/wp-includes/plugin.php
index e02139d1c1..d616a2a960 100644
--- a/src/wp-includes/plugin.php
+++ b/src/wp-includes/plugin.php
@@ -105,6 +105,7 @@ function add_filter( $tag, $function_to_add, $priority = 10, $accepted_args = 1
  *                  return value.
  */
 function has_filter($tag, $function_to_check = false) {
+	// Don't reset the internal array pointer
 	$wp_filter = $GLOBALS['wp_filter'];
 
 	$has = ! empty( $wp_filter[ $tag ] );
diff --git a/tests/phpunit/tests/filters.php b/tests/phpunit/tests/filters.php
index 34fdf56355..b4ee12f353 100644
--- a/tests/phpunit/tests/filters.php
+++ b/tests/phpunit/tests/filters.php
@@ -293,4 +293,25 @@ class Tests_Filters extends WP_UnitTestCase {
 		remove_all_filters( $tag, 12 );
 		$this->assertFalse( has_filter( $tag ) );
 	}
+
+	/**
+	 * @ticket 29070
+	 */
+	 function test_has_filter_doesnt_reset_wp_filter() {
+	 	add_action( 'action_test_has_filter_doesnt_reset_wp_filter', '__return_null', 1 );
+	 	add_action( 'action_test_has_filter_doesnt_reset_wp_filter', '__return_null', 2 );
+	 	add_action( 'action_test_has_filter_doesnt_reset_wp_filter', '__return_null', 3 );
+	 	add_action( 'action_test_has_filter_doesnt_reset_wp_filter', array( $this, '_action_test_has_filter_doesnt_reset_wp_filter' ), 4 );
+
+	 	do_action( 'action_test_has_filter_doesnt_reset_wp_filter' );
+	 }
+	 function _action_test_has_filter_doesnt_reset_wp_filter() {
+	 	global $wp_filter;
+
+	 	has_action( 'action_test_has_filter_doesnt_reset_wp_filter', '_function_that_doesnt_exist' );
+
+		$filters = current( $wp_filter['action_test_has_filter_doesnt_reset_wp_filter'] );
+	 	$the_ = current( $filters );
+	 	$this->assertEquals( $the_['function'], array( $this, '_action_test_has_filter_doesnt_reset_wp_filter' ) );
+	 }
 }