From 8cc8eb5401867fd42868bd8677358800712bfc91 Mon Sep 17 00:00:00 2001
From: Weston Ruter <westonruter@git.wordpress.org>
Date: Tue, 11 Feb 2025 20:02:29 +0000
Subject: [PATCH] HTML API: Stop counting no-op seek operations against the max
 seek count.

This allows `seek()` to be freely called when the current cursor at the provided bookmark.

Props dmsnell, jonsurrell, westonruter.
Fixes #62085.


git-svn-id: https://develop.svn.wordpress.org/trunk@59812 602fd350-edb4-49c9-b593-d223f7449a82
---
 .../html-api/class-wp-html-tag-processor.php  |  9 ++++
 .../html-api/wpHtmlTagProcessor-bookmark.php  | 41 +++++++++++++++++--
 2 files changed, 46 insertions(+), 4 deletions(-)

diff --git a/src/wp-includes/html-api/class-wp-html-tag-processor.php b/src/wp-includes/html-api/class-wp-html-tag-processor.php
index 39390621e86a6..032ca2af32e57 100644
--- a/src/wp-includes/html-api/class-wp-html-tag-processor.php
+++ b/src/wp-includes/html-api/class-wp-html-tag-processor.php
@@ -2551,6 +2551,15 @@ public function seek( $bookmark_name ): bool {
 			return false;
 		}
 
+		$existing_bookmark = $this->bookmarks[ $bookmark_name ];
+
+		if (
+			$this->token_starts_at === $existing_bookmark->start &&
+			$this->token_length === $existing_bookmark->length
+		) {
+			return true;
+		}
+
 		if ( ++$this->seek_count > static::MAX_SEEK_OPS ) {
 			_doing_it_wrong(
 				__METHOD__,
diff --git a/tests/phpunit/tests/html-api/wpHtmlTagProcessor-bookmark.php b/tests/phpunit/tests/html-api/wpHtmlTagProcessor-bookmark.php
index ad0cf68906245..0e72f9d726835 100644
--- a/tests/phpunit/tests/html-api/wpHtmlTagProcessor-bookmark.php
+++ b/tests/phpunit/tests/html-api/wpHtmlTagProcessor-bookmark.php
@@ -435,16 +435,49 @@ public function test_limits_the_number_of_bookmarks() {
 	public function test_limits_the_number_of_seek_calls() {
 		$processor = new WP_HTML_Tag_Processor( '<ul><li>One</li><li>Two</li><li>Three</li></ul>' );
 		$processor->next_tag( 'li' );
-		$processor->set_bookmark( 'bookmark' );
-
-		for ( $i = 0; $i < WP_HTML_Tag_Processor::MAX_SEEK_OPS; $i++ ) {
-			$this->assertTrue( $processor->seek( 'bookmark' ), 'Could not seek to the "bookmark"' );
+		$processor->set_bookmark( 'ping' );
+		$processor->next_tag( 'li' );
+		$processor->set_bookmark( 'pong' );
+
+		for ( $i = 0; $i < WP_HTML_Tag_Processor::MAX_SEEK_OPS; $i += 2 ) {
+			$this->assertTrue(
+				$processor->seek( 'ping' ),
+				'Could not seek to the "ping": check test setup.'
+			);
+
+			$this->assertTrue(
+				$processor->seek( 'pong' ),
+				'Could not seek to the "pong": check test setup.'
+			);
 		}
 
 		$this->setExpectedIncorrectUsage( 'WP_HTML_Tag_Processor::seek' );
 		$this->assertFalse( $processor->seek( 'bookmark' ), "$i-th seek() to the bookmark succeeded, even though it should exceed the allowed limit" );
 	}
 
+	/**
+	 * @ticket 62085
+	 *
+	 * @covers WP_HTML_Tag_Processor::seek
+	 */
+	public function test_skips_counting_noop_seek_calls() {
+		$processor = new WP_HTML_Tag_Processor( '<ul><li>One</li><li>Two</li><li>Three</li></ul>' );
+		$processor->next_tag( 'li' );
+		$processor->set_bookmark( 'here' );
+
+		for ( $i = 0; $i < WP_HTML_Tag_Processor::MAX_SEEK_OPS; $i++ ) {
+			$this->assertTrue(
+				$processor->seek( 'here' ),
+				'Could not seek to the "here": check test setup.'
+			);
+		}
+
+		$this->assertTrue(
+			$processor->seek( 'here' ),
+			'Should never fail to seek if the seek is pointing at the current location.'
+		);
+	}
+
 	/**
 	 * Ensures that it's possible to seek to an earlier location in a document even
 	 * after reaching the end of a document, when most functionality shuts down.