From 8f855f46b08cb2a3e0b2f11103bca8621db20221 Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov.ru@gmail.com>
Date: Fri, 3 Feb 2017 20:58:42 +0000
Subject: [PATCH] Media: In `wp_unique_filename()`, use explicit type casting
 when incrementing `$number`.

This prevents the "non-numeric value encountered" warning in PHP 7.1, caused by trying to increment an empty string on the first loop iteration.

Props drrobotnik for initial patch.
Fixes #39774.


Built from https://develop.svn.wordpress.org/trunk@40039


git-svn-id: http://core.svn.wordpress.org/trunk@39976 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/functions.php | 8 +++++---
 wp-includes/version.php   | 2 +-
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/wp-includes/functions.php b/wp-includes/functions.php
index 3923ca92ec..865c0d29b5 100644
--- a/wp-includes/functions.php
+++ b/wp-includes/functions.php
@@ -2063,7 +2063,7 @@ function wp_unique_filename( $dir, $filename, $unique_filename_callback = null )
 
 			// Check for both lower and upper case extension or image sub-sizes may be overwritten.
 			while ( file_exists($dir . "/$filename") || file_exists($dir . "/$filename2") ) {
-				$new_number = $number + 1;
+				$new_number = (int) $number + 1;
 				$filename = str_replace( array( "-$number$ext", "$number$ext" ), "-$new_number$ext", $filename );
 				$filename2 = str_replace( array( "-$number$ext2", "$number$ext2" ), "-$new_number$ext2", $filename2 );
 				$number = $new_number;
@@ -2083,11 +2083,13 @@ function wp_unique_filename( $dir, $filename, $unique_filename_callback = null )
 		}
 
 		while ( file_exists( $dir . "/$filename" ) ) {
+			$new_number = (int) $number + 1;
 			if ( '' == "$number$ext" ) {
-				$filename = "$filename-" . ++$number;
+				$filename = "$filename-" . $new_number;
 			} else {
-				$filename = str_replace( array( "-$number$ext", "$number$ext" ), "-" . ++$number . $ext, $filename );
+				$filename = str_replace( array( "-$number$ext", "$number$ext" ), "-" . $new_number . $ext, $filename );
 			}
+			$number = $new_number;
 		}
 	}
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index e811f87753..f9bfa1d074 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.8-alpha-40038';
+$wp_version = '4.8-alpha-40039';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.