Index: taxonomy.php
===================================================================
--- taxonomy.php	(revision 49555)
+++ taxonomy.php	(working copy)
@@ -1426,7 +1426,7 @@
 	$select     = "SELECT term_id FROM $wpdb->terms as t WHERE ";
 	$tax_select = "SELECT tt.term_id, tt.term_taxonomy_id FROM $wpdb->terms AS t INNER JOIN $wpdb->term_taxonomy as tt ON tt.term_id = t.term_id WHERE ";
 
-	if ( is_int( $term ) ) {
+	if ( ctype_digit( $term ) ) {
 		if ( 0 === $term ) {
 			return 0;
 		}
@@ -2217,7 +2217,7 @@
 		return $term;
 	}
 
-	if ( is_int( $term ) && 0 === $term ) {
+	if ( ctype_digit( $term ) && 0 === $term ) {
 		return new WP_Error( 'invalid_term_id', __( 'Invalid term ID.' ) );
 	}
 
@@ -2592,7 +2592,7 @@
 
 		if ( ! $term_info ) {
 			// Skip if a non-existent term ID is passed.
-			if ( is_int( $term ) ) {
+			if ( ctype_digit( $term ) ) {
 				continue;
 			}
 
@@ -2762,7 +2762,7 @@
 		$term_info = term_exists( $term, $taxonomy );
 		if ( ! $term_info ) {
 			// Skip if a non-existent term ID is passed.
-			if ( is_int( $term ) ) {
+			if ( ctype_digit( $term ) ) {
 				continue;
 			}
 		}
@@ -4344,7 +4344,7 @@
 	global $wp_rewrite;
 
 	if ( ! is_object( $term ) ) {
-		if ( is_int( $term ) ) {
+		if ( ctype_digit( $term ) ) {
 			$term = get_term( $term, $taxonomy );
 		} else {
 			$term = get_term_by( 'slug', $term, $taxonomy );
@@ -4599,7 +4599,7 @@
 
 	$terms = (array) $terms;
 
-	$ints = array_filter( $terms, 'is_int' );
+	$ints = array_filter( $terms, 'ctype_digit' );
 	if ( $ints ) {
 		$strs = array_diff( $terms, $ints );
 	} else {