Merge remote-tracking branch 'upstream' into 6-9/dependency-updates

Author: desrosj

.github/workflows/phpunit-tests.yml

@@ -211,7 +211,7 @@ jobs:
         os: [ ubuntu-24.04 ]
         php: [ '7.2', '7.3', '7.4', '8.0', '8.1', '8.2', '8.3', '8.4', '8.5' ]
         db-type: [ 'mariadb' ]
-        db-version: [ '5.5', '10.3', '10.4', '10.5', '10.6', '10.11', '11.4', '11.8' ]
+        db-version: [ '5.5', '10.3', '10.5', '10.6', '10.11', '11.4', '11.8' ]
         multisite: [ false, true ]
         memcached: [ false ]
 
@@ -222,9 +222,6 @@ jobs:
           - event: pull_request
             php: '7.2'
             db-version: '10.3'
-          - event: pull_request
-            php: '7.2'
-            db-version: '10.4'
           - event: pull_request
             php: '7.2'
             db-version: '10.5'
@@ -243,9 +240,6 @@ jobs:
           - event: pull_request
             php: '7.3'
             db-version: '5.5'
-          - event: pull_request
-            php: '7.3'
-            db-version: '10.4'
           - event: pull_request
             php: '7.3'
             db-version: '10.5'
@@ -288,9 +282,6 @@ jobs:
           - event: pull_request
             php: '8.0'
             db-version: '10.3'
-          - event: pull_request
-            php: '8.0'
-            db-version: '10.4'
           - event: pull_request
             php: '8.0'
             db-version: '10.6'
@@ -309,9 +300,6 @@ jobs:
           - event: pull_request
             php: '8.1'
             db-version: '10.3'
-          - event: pull_request
-            php: '8.1'
-            db-version: '10.4'
           - event: pull_request
             php: '8.1'
             db-version: '10.5'
@@ -330,9 +318,6 @@ jobs:
           - event: pull_request
             php: '8.2'
             db-version: '10.3'
-          - event: pull_request
-            php: '8.2'
-            db-version: '10.4'
           - event: pull_request
             php: '8.2'
             db-version: '10.5'
@@ -351,9 +336,6 @@ jobs:
           - event: pull_request
             php: '8.3'
             db-version: '10.3'
-          - event: pull_request
-            php: '8.3'
-            db-version: '10.4'
           - event: pull_request
             php: '8.3'
             db-version: '10.5'
@@ -372,9 +354,6 @@ jobs:
           - event: pull_request
             php: '8.4'
             db-version: '10.3'
-          - event: pull_request
-            php: '8.4'
-            db-version: '10.4'
           - event: pull_request
             php: '8.4'
             db-version: '10.5'
@@ -393,9 +372,6 @@ jobs:
           - event: pull_request
             php: '8.5'
             db-version: '10.3'
-          - event: pull_request
-            php: '8.5'
-            db-version: '10.4'
           - event: pull_request
             php: '8.5'
             db-version: '10.5'

src/wp-includes/pluggable.php

@@ -384,6 +384,15 @@ function wp_mail( $to, $subject, $message, $headers = '', $attachments = array()
 		$phpmailer->Body    = '';
 		$phpmailer->AltBody = '';
 
+		/*
+		 * Reset encoding to 8-bit, as it may have been automatically downgraded
+		 * to 7-bit by PHPMailer (based on the body contents) in a previous call
+		 * to wp_mail().
+		 *
+		 * See https://core.trac.wordpress.org/ticket/33972
+		 */
+		$phpmailer->Encoding = PHPMailer\PHPMailer\PHPMailer::ENCODING_8BIT;
+
 		// Set "From" name and email.
 
 		// If we don't have a name from the input headers.

tests/phpunit/includes/mock-mailer.php

@@ -20,7 +20,6 @@ class MockPHPMailer extends WP_PHPMailer {
 	public $mock_sent = array();
 
 	public function preSend() {
-		$this->Encoding = '8bit';
 		return parent::preSend();
 	}
 

tests/phpunit/tests/pluggable/wpMail.php

@@ -651,4 +651,22 @@ public function test_wp_mail_string_embeds() {
 			$this->assertStringContainsString( 'cid:' . $key, $mailer->get_sent()->body, 'The cid ' . $key . ' is not referenced in the mail body.' );
 		}
 	}
+
+	/**
+	 * Test that the encoding of the email does not bleed between long and short emails.
+	 *
+	 * @ticket 33972
+	 */
+	public function test_wp_mail_encoding_does_not_bleed() {
+		$content = str_repeat( 'A', 1000 );
+		wp_mail( WP_TESTS_EMAIL, 'Looong line testing', $content );
+
+		$mailer = tests_retrieve_phpmailer_instance();
+		$this->assertEquals( 'quoted-printable', $mailer->Encoding );
+
+		wp_mail( WP_TESTS_EMAIL, 'A follow up short email', 'Short email' );
+
+		$mailer = tests_retrieve_phpmailer_instance();
+		$this->assertEquals( '7bit', $mailer->Encoding );
+	}
 }