From 5d30435e81427fcce3353d900faaf8d9fa9a8709 Mon Sep 17 00:00:00 2001
From: Kunal Mehta <legoktm@member.fsf.org>
Date: Wed, 25 Apr 2018 22:24:24 -0700
Subject: [PATCH] mail: Refactor checks looking for PEAR libraries to be
 clearer

I don't think this makes any difference towards the linked bug, but
it makes it more obvious that MediaWiki doesn't try to use any PEAR
classes before attempting to require them.

Bug: T186456
Change-Id: I342f41903a15f13e72e76464499351412a9afa34
---
 includes/mail/UserMailer.php | 55 ++++++++++++++++++++++++++++--------
 1 file changed, 44 insertions(+), 11 deletions(-)

diff --git a/includes/mail/UserMailer.php b/includes/mail/UserMailer.php
index fb0f2f99f0..7b48ad095a 100644
--- a/includes/mail/UserMailer.php
+++ b/includes/mail/UserMailer.php
@@ -189,6 +189,46 @@ class UserMailer {
 		return self::sendInternal( $to, $from, $subject, $body, $options );
 	}
 
+	/**
+	 * Whether the PEAR Mail_mime library is usable. This will
+	 * try and load it if it is not already.
+	 *
+	 * @return bool
+	 */
+	private static function isMailMimeUsable() {
+		static $usable = null;
+		if ( $usable === null ) {
+			// If the class is not already loaded, and it's in the include path,
+			// try requiring it.
+			if ( !class_exists( 'Mail_mime' ) && stream_resolve_include_path( 'Mail/mime.php' ) ) {
+				require_once 'Mail/mime.php';
+			}
+			$usable = class_exists( 'Mail_mime' );
+		}
+
+		return $usable;
+	}
+
+	/**
+	 * Whether the PEAR Mail library is usable. This will
+	 * try and load it if it is not already.
+	 *
+	 * @return bool
+	 */
+	private static function isMailUsable() {
+		static $usable = null;
+		if ( $usable === null ) {
+			// If the class is not already loaded, and it's in the include path,
+			// try requiring it.
+			if ( !class_exists( 'Mail' ) && stream_resolve_include_path( 'Mail.php' ) ) {
+				require_once 'Mail.php';
+			}
+			$usable = class_exists( 'Mail' );
+		}
+
+		return $usable;
+	}
+
 	/**
 	 * Helper function fo UserMailer::send() which does the actual sending. It expects a $to
 	 * list which the UserMailerSplitTo hook would not split further.
@@ -296,15 +336,12 @@ class UserMailer {
 		if ( is_array( $body ) ) {
 			// we are sending a multipart message
 			wfDebug( "Assembling multipart mime email\n" );
-			if ( !stream_resolve_include_path( 'Mail/mime.php' ) ) {
+			if ( !self::isMailMimeUsable() ) {
 				wfDebug( "PEAR Mail_Mime package is not installed. Falling back to text email.\n" );
 				// remove the html body for text email fall back
 				$body = $body['text'];
 			} else {
-				// Check if pear/mail_mime is already loaded (via composer)
-				if ( !class_exists( 'Mail_mime' ) ) {
-					require_once 'Mail/mime.php';
-				}
+				// pear/mail_mime is already loaded by this point
 				if ( wfIsWindows() ) {
 					$body['text'] = str_replace( "\n", "\r\n", $body['text'] );
 					$body['html'] = str_replace( "\n", "\r\n", $body['html'] );
@@ -352,12 +389,8 @@ class UserMailer {
 
 		if ( is_array( $wgSMTP ) ) {
 			// Check if pear/mail is already loaded (via composer)
-			if ( !class_exists( 'Mail' ) ) {
-				// PEAR MAILER
-				if ( !stream_resolve_include_path( 'Mail.php' ) ) {
-					throw new MWException( 'PEAR mail package is not installed' );
-				}
-				require_once 'Mail.php';
+			if ( !self::isMailUsable() ) {
+				throw new MWException( 'PEAR mail package is not installed' );
 			}
 
 			Wikimedia\suppressWarnings();
-- 
2.20.1