From ff7226364325ea09037636f032c2c9a9f15052fb Mon Sep 17 00:00:00 2001
From: Sergey Biryukov <sergeybiryukov.ru@gmail.com>
Date: Mon, 23 Mar 2026 14:55:58 +0000
Subject: [PATCH] Code Modernization: Replace the deprecated
 `auto_detect_line_endings` setting.
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Since PHP 8.1, the `auto_detect_line_endings` setting is deprecated:

> The `auto_detect_line_endings` ini setting modifies the behavior of `file()` and `fgets()` to support an isolated `\r` (as opposed to `\n` or `\r\n`) as a newline character. These newlines were used by “Classic” Mac OS, a system which has been discontinued in 2001, nearly two decades ago. Interoperability with such systems is no longer relevant.

Reference: [https://wiki.php.net/rfc/deprecations_php_8_1#auto_detect_line_endings_ini_setting PHP RFC: Deprecations for PHP 8.1: auto_detect_line_endings ini setting].

> The `auto_detect_line_endings` ini setting has been deprecated. If necessary, handle `\r` line breaks manually instead.

Reference: [https://github.com/php/php-src/blob/1cf4fb739f7a4fa8404a4c0958f13d04eae519d4/UPGRADING#L456-L457 PHP 8.1 Upgrade Notes].

This commits adds code to replace the deprecated setting and still handle old-style `\r` line-terminated files in `PO::read_line()` using `strpos()` + `fseek()`. Includes a unit test covering `\r`, `\n`, and `\r\n` line endings.

Follow-up to [51633], [51636].

Props akirk, apermo, westonruter, SergeyBiryukov.
Fixes #64928.
Built from https://develop.svn.wordpress.org/trunk@62093


git-svn-id: http://core.svn.wordpress.org/trunk@61375 1a063a9b-81f0-0310-95a4-ce76da25c4cd
---
 wp-includes/pomo/po.php | 37 +++++++++++++++++++++++++------------
 wp-includes/version.php |  2 +-
 2 files changed, 26 insertions(+), 13 deletions(-)

diff --git a/wp-includes/pomo/po.php b/wp-includes/pomo/po.php
index de1bc92064..c43544e142 100644
--- a/wp-includes/pomo/po.php
+++ b/wp-includes/pomo/po.php
@@ -13,16 +13,6 @@ if ( ! defined( 'PO_MAX_LINE_LEN' ) ) {
 	define( 'PO_MAX_LINE_LEN', 79 );
 }
 
-/*
- * The `auto_detect_line_endings` setting has been deprecated in PHP 8.1,
- * but will continue to work until PHP 9.0.
- * For now, we're silencing the deprecation notice as there may still be
- * translation files around which haven't been updated in a long time and
- * which still use the old MacOS standalone `\r` as a line ending.
- * This fix should be revisited when PHP 9.0 is in alpha/beta.
- */
-@ini_set( 'auto_detect_line_endings', 1 ); // phpcs:ignore WordPress.PHP.NoSilencedErrors.Discouraged
-
 /**
  * Routines for working with PO files
  */
@@ -475,8 +465,31 @@ if ( ! class_exists( 'PO', false ) ) :
 				$use_last_line = true;
 				return true;
 			}
-			$line          = $use_last_line ? $last_line : fgets( $f );
-			$line          = ( "\r\n" === substr( $line, -2 ) ) ? rtrim( $line, "\r\n" ) . "\n" : $line;
+
+			if ( $use_last_line ) {
+				$line = $last_line;
+			} else {
+				$line = fgets( $f );
+				if ( false === $line ) {
+					return $line;
+				}
+
+				// Handle \r-only terminated lines after the deprecation of auto_detect_line_endings in PHP 8.1.
+				$r = strpos( $line, "\r" );
+				if ( false !== $r ) {
+					if ( strlen( $line ) === $r + 1
+						&& "\r\n" === substr( $line, $r )
+					) {
+						$line = rtrim( $line, "\r\n" ) . "\n";
+					} else {
+						// The lines are terminated by just \r, so we end the line there and rewind.
+						$rewind = strlen( $line ) - $r - 1;
+						$line   = substr( $line, 0, $r ) . "\n";
+						fseek( $f, - $rewind, SEEK_CUR );
+					}
+				}
+			}
+
 			$last_line     = $line;
 			$use_last_line = false;
 			return $line;
diff --git a/wp-includes/version.php b/wp-includes/version.php
index 0374aa68b6..9756b560ce 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '7.0-beta6-62092';
+$wp_version = '7.0-beta6-62093';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.