Ticket #41451: 41451.patch

tests/phpunit/includes/functions.php

@@ -157 +157 @@
         update_option( 'permalink_structure', '/%year%/%monthnum%/%day%/%postname%/' );
 }
 
+function _set_default_multisite_permalink_structure_for_tests() {
+        update_option( 'permalink_structure', '/blog/%year%/%monthnum%/%day%/%postname%/' );
+}
+
 /**
  * Helper used with the `upload_dir` filter to remove the /year/month sub directories from the uploads path and URL.
  */

tests/phpunit/includes/install.php

@@ -65 +65 @@
 $wpdb->query( 'SET foreign_key_checks = 1' );
 
 // Prefill a permalink structure so that WP doesn't try to determine one itself.
-add_action( 'populate_options', '_set_default_permalink_structure_for_tests' );
+if ( $multisite ) {
+        add_action( 'populate_options', '_set_default_multisite_permalink_structure_for_tests' );
+} else {
+        add_action( 'populate_options', '_set_default_permalink_structure_for_tests' );
+}
 
 wp_install( WP_TESTS_TITLE, 'admin', WP_TESTS_EMAIL, true, null, 'password' );
 
-// Delete dummy permalink structure, as prefilled above.
-if ( ! is_multisite() ) {
-        delete_option( 'permalink_structure' );
+if ( $multisite ) {
+        remove_action( 'populate_options', '_set_default_multisite_permalink_structure_for_tests' );
+} else {
+        remove_action( 'populate_options', '_set_default_permalink_structure_for_tests' );
 }
-remove_action( 'populate_options', '_set_default_permalink_structure_for_tests' );
 
 if ( $multisite ) {
         echo 'Installing network...' . PHP_EOL;
@@ -85 +89 @@
 
         install_network();
         populate_network( 1, WP_TESTS_DOMAIN, WP_TESTS_EMAIL, $title, '/', $subdomain_install );
-        $wp_rewrite->set_permalink_structure( '' );
 }

tests/phpunit/includes/testcase.php

@@ -125 +125 @@
                         $this->reset_taxonomies();
                         $this->reset_post_statuses();
                         $this->reset__SERVER();
-
-                        if ( $wp_rewrite->permalink_structure ) {
-                                $this->set_permalink_structure( '' );
-                        }
                 }
 
                 $this->start_transaction();
                 $this->expectDeprecated();
                 add_filter( 'wp_die_handler', array( $this, 'get_wp_die_handler' ) );
+
+                if ( get_option( 'permalink_structure' ) !== tests_get_default_permalink_structure() ) {
+                        $this->fail( 'Permalink structure was not correctly reset: ' . get_option( 'permalink_structure' ) );
+                }
         }
 
         /**

tests/phpunit/includes/utils.php

@@ -534 +534 @@
         }
         return $links;
 }
+
+/**
+ * Set the permalink structure.
+ *
+ * This updates the `permalink_structure` option, and flushes the existing rewrite rules.
+ *
+ * @since 5.0.0
+ *
+ * @param string $structure Permalink structure.
+ */
+function tests_set_and_flush_permalinks( $structure ) {
+        global $wp_rewrite;
+
+        $wp_rewrite->set_permalink_structure( $structure );
+        $wp_rewrite->flush_rules();
+}
+
+/**
+ * Reset the permalink structure to the default.
+ *
+ * @since 5.0.0
+ */
+function tests_reset_and_flush_permalinks() {
+        tests_set_and_flush_permalinks( tests_get_default_permalink_structure() );
+}
+
+/**
+ * Retrieve the default permalink structure used for unit tests.
+ *
+ * @since 5.0.0
+ *
+ * @return string Permalink structure.
+ */
+function tests_get_default_permalink_structure() {
+        if ( is_multisite() ) {
+                return '/blog/%year%/%monthnum%/%day%/%postname%/';
+        }
+
+        return '/%year%/%monthnum%/%day%/%postname%/';
+}
+
+/**
+ * Add the `blog` prefix to URLs if on multisite.
+ *
+ * When the multisite is installed, the main site gets `blog` added to its permalink structure. This makes the
+ * permalinks different on single site installs and on multisites.
+ *
+ * This helper function prefixes URLs with `blog` if on multisite.
+ *
+ * @since 5.0.0
+ *
+ * @param string $url URL to maybe prefix.
+ *
+ * @return string Prefixed URL on multisite, else unchanged URL.
+ */
+function tests_add_blog_permalink_prefix_on_multisite( $url ) {
+        if ( ! is_multisite() || ! is_main_site() ) {
+                return $url;
+        }
+
+        if ( strpos( $url, '/' ) === 0 ) {
+                return 'blog' . $url;
+        }
+
+        return 'blog/' . $url;
+}

tests/phpunit/tests/admin/includesPost.php

@@ -333 +333 @@
                 $expected = trailingslashit( home_url( $permalink_structure ) );
 
                 $this->assertSame( $expected, $found[0] );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -340 +342 @@
          * @ticket 18306
          */
         public function test_get_sample_permalink_html_should_use_default_permalink_for_view_post_link_when_pretty_permalinks_are_disabled() {
+                tests_set_and_flush_permalinks( '' );
+
                 wp_set_current_user( self::$admin_id );
 
                 $future_date = date( 'Y-m-d H:i:s', time() + 100 );
@@ -354 +358 @@
                 $found = get_sample_permalink_html( $p );
                 $this->assertContains( 'href="' . get_option( 'home' ) . '/?p=' . $p . '"', $found );
                 $this->assertContains( '>' . get_option( 'home' ) . '/?p=' . $p . '<', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -378 +384 @@
                 $post  = get_post( $p );
                 $this->assertContains( 'href="' . get_option( 'home' ) . '/' . $post->post_name . '/"', $found );
                 $this->assertContains( '>' . urldecode( $post->post_name ) . '<', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -401 +409 @@
                 $post  = get_post( $p );
                 $this->assertContains( 'href="' . get_option( 'home' ) . '/' . $post->post_name . '/"', $found );
                 $this->assertContains( '>' . urldecode( get_permalink( $post ) ) . '<', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -459 +469 @@
 
                 $this->assertContains( 'href="' . esc_url( $preview_link ) . '"', $found, $message );
                 $this->assertContains( '>new_slug-صورة<', $found, $message );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -482 +494 @@
                 $found = get_sample_permalink_html( $p );
                 $post  = get_post( $p );
                 $this->assertContains( 'href="' . esc_url( get_preview_post_link( $post ) ), $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -498 +512 @@
 
                 $found = get_sample_permalink( $p );
                 $this->assertEquals( '2015-2', $found[1] );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -514 +530 @@
 
                 $found = get_sample_permalink( $p );
                 $this->assertEquals( '2015', $found[1] );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -530 +548 @@
 
                 $found = get_sample_permalink( $p );
                 $this->assertEquals( '11-2', $found[1] );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -546 +566 @@
 
                 $found = get_sample_permalink( $p );
                 $this->assertEquals( '13', $found[1] );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -562 +584 @@
 
                 $found = get_sample_permalink( $p );
                 $this->assertEquals( '30-2', $found[1] );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -584 +608 @@
 
                 $found = get_sample_permalink( $p );
                 $this->assertEquals( '30-3', $found[1] );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -600 +626 @@
 
                 $found = get_sample_permalink( $p );
                 $this->assertEquals( '32', $found[1] );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -616 +644 @@
 
                 $found = get_sample_permalink( $p );
                 $this->assertEquals( '30', $found[1] );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -643 +673 @@
                 $actual = get_sample_permalink( $child );
                 $this->assertSame( home_url() . '/parent-page/%pagename%/', $actual[0] );
                 $this->assertSame( 'child-page', $actual[1] );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_post_exists_should_match_title() {

tests/phpunit/tests/canonical/https.php

@@ -9 +9 @@
         function setUp() {
                 parent::setUp();
 
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
                 create_initial_taxonomies();
 
                 $this->http  = set_url_scheme( home_url( 'sample-page/' ), 'http' );

tests/phpunit/tests/category/getCategoryLink.php

@@ -6 +6 @@
  */
 class Tests_Category_GetCategoryLink extends WP_UnitTestCase {
         public function test_success() {
+                tests_set_and_flush_permalinks( '' );
                 $c = self::factory()->category->create();
 
                 $found = get_category_link( $c );
                 $expected = home_url( '?cat=' . $c );
 
                 $this->assertSame( $expected, $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 42771
          */
         public function test_should_return_link_for_term_from_another_taxonomy_on_primed_cache() {
+                tests_set_and_flush_permalinks( '' );
                 register_taxonomy( 'wptests_tax', 'post' );
 
                 $t = self::factory()->term->create( array(
@@ -31 +35 @@
                 $expected = home_url( '?wptests_tax=test-term' );
 
                 $this->assertSame( $expected, $found );
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 42771
          */
         public function test_should_return_link_for_term_from_another_taxonomy_on_empty_cache() {
+                tests_set_and_flush_permalinks( '' );
                 register_taxonomy( 'wptests_tax', 'post' );
 
                 $t = self::factory()->term->create( array(
@@ -50 +56 @@
                 $expected = home_url( '?wptests_tax=test-term' );
 
                 $this->assertSame( $expected, $found );
+                tests_reset_and_flush_permalinks();
         }
 }

tests/phpunit/tests/comment/commentsTemplate.php

@@ -570 +570 @@
 
                 // They should all be on page 2.
                 foreach ( $matches[1] as $m ) {
-                        $this->assertContains( 'cpage=2', $m );
+                        $this->assertContains( 'comment-page-2', $m );
                 }
         }
 
@@ -641 +641 @@
                 preg_match_all( '|href="(.*?#comment-([0-9]+))|', $found_p0, $matches );
 
                 foreach ( $matches[1] as $m ) {
-                        $this->assertContains( 'cpage=3', $m );
+                        $this->assertContains( 'comment-page-3', $m );
                 }
 
                 $link_p2 = add_query_arg(
@@ -660 +660 @@
 
                 // They should all be on page 2.
                 foreach ( $matches[1] as $m ) {
-                        $this->assertContains( 'cpage=2', $m );
+                        $this->assertContains( 'comment-page-2', $m );
                 }
 
                 // p1 is the last page (neat!).
@@ -680 +680 @@
 
                 // They should all be on page 2.
                 foreach ( $matches[1] as $m ) {
-                        $this->assertContains( 'cpage=1', $m );
+                        $this->assertContains( 'comment-page-1', $m );
                 }
         }
 

tests/phpunit/tests/comment/getCommentLink.php

@@ -66 +66 @@
 
                 $found = get_comment_link( self::$comments[1] );
 
-                $this->assertContains( 'cpage=3', $found );
+                $this->assertContains( 'comment-page-3', $found );
         }
 
         /**
@@ -79 +79 @@
 
                 $found = get_comment_link( self::$comments[3] );
 
-                $this->assertContains( 'cpage=2', $found );
+                $this->assertContains( 'comment-page-2', $found );
         }
 
         /**
@@ -92 +92 @@
 
                 $found = get_comment_link( self::$comments[5] );
 
-                $this->assertContains( 'cpage=1', $found );
+                $this->assertContains( 'comment-page-1', $found );
         }
 
         /**
@@ -117 +117 @@
 
                 $found = get_comment_link( self::$comments[3] );
 
-                $this->assertContains( 'cpage=2', $found );
+                $this->assertContains( 'comment-page-2', $found );
         }
 
         /**
@@ -130 +130 @@
 
                 $found = get_comment_link( self::$comments[1] );
 
-                $this->assertContains( 'cpage=3', $found );
+                $this->assertContains( 'comment-page-3', $found );
         }
 
         /**
          * @ticket 34946
          */
         public function test_should_not_contain_comment_page_1_when_pagination_is_disabled() {
-                $this->set_permalink_structure( '/%postname%/' );
                 update_option( 'page_comments', 0 );
 
                 $found = get_comment_link( self::$comments[1] );

tests/phpunit/tests/feed/atom.php

@@ -17 +17 @@
          * Setup a new user and attribute some posts.
          */
         public static function wpSetUpBeforeClass( $factory ) {
+                global $wpdb;
+
                 // Create a user
                 self::$user_id = $factory->user->create(
                         array(
@@ -50 +52 @@
                         wp_set_object_terms( $post, self::$category->slug, 'category' );
                 }
 
+                // Manually update the posts `guid` to be non-pretty permalinks. Due to the way that `wp_insert_post()` works,
+                // the `guid` fields all contain pretty permalinks.
+                foreach( self::$posts as $post_ID ) {
+                        $wpdb->update( $wpdb->posts, array( 'guid' => 'http://example.com/?p=' . $post_ID ), array( 'ID' => $post_ID ) );
+                }
         }
 
         /**

tests/phpunit/tests/feed/rss2.php

@@ -18 +18 @@
          * Setup a new user and attribute some posts.
          */
         public static function wpSetUpBeforeClass( $factory ) {
+                global $wpdb;
+
                 // Create a user
                 self::$user_id = $factory->user->create(
                         array(
@@ -50 +52 @@
                         )
                 );
 
+                // Manually update the posts `guid` to be non-pretty permalinks. Due to the way that `wp_insert_post()` works,
+                // the `guid` fields all contain pretty permalinks.
+                foreach( self::$posts as $post_ID ) {
+                        $wpdb->update( $wpdb->posts, array( 'guid' => 'http://example.com/?p=' . $post_ID ), array( 'ID' => $post_ID ) );
+                }
+
                 // Assign a category to those posts
                 foreach ( self::$posts as $post ) {
                         wp_set_object_terms( $post, self::$category->slug, 'category' );
@@ -67 +75 @@
                 // this seems to break something
                 update_option( 'use_smilies', false );
 
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
                 create_initial_taxonomies();
         }
 
@@ -326 +333 @@
          */
         function test_valid_taxonomy_feed_endpoint() {
                 // An example of an valid taxonomy feed endpoint.
-                $this->go_to( 'category/foo/feed/' );
+                $this->go_to( '/' . tests_add_blog_permalink_prefix_on_multisite( 'category/foo/feed/' ) );
 
                 // Verify the query object is a feed.
                 $this->assertQueryTrue( 'is_feed', 'is_archive', 'is_category' );
@@ -387 +394 @@
          */
         function test_valid_archive_feed_endpoint() {
                 // An example of an valid date archive feed endpoint.
-                $this->go_to( '2003/05/27/feed/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( '2003/05/27/feed/' ) );
 
                 // Verify the query object is a feed.
                 $this->assertQueryTrue( 'is_feed', 'is_archive', 'is_day', 'is_date' );

tests/phpunit/tests/general/paginateLinks.php

@@ -213 +213 @@
          * @ticket 29636
          */
         function test_paginate_links_query_args() {
+                tests_set_and_flush_permalinks( '' );
+
                 add_filter( 'get_pagenum_link', array( $this, 'add_query_arg' ) );
                 $links = paginate_links(
                         array(
@@ -245 +247 @@
                         $href = $tag->attributes->getNamedItem( 'href' )->value;
                         $this->assertEquals( $expected_href, $href );
                 }
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 30831
          */
         function test_paginate_links_with_custom_query_args() {
+                tests_set_and_flush_permalinks( '' );
+
                 add_filter( 'get_pagenum_link', array( $this, 'add_query_arg' ) );
                 $links = paginate_links(
                         array(
@@ -285 +291 @@
                         $href = $tag->attributes->getNamedItem( 'href' )->value;
                         $this->assertEquals( $expected_href, $href );
                 }
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**

tests/phpunit/tests/link.php

@@ -14 +14 @@
         function test_get_pagenum_link_case_insensitivity() {
                 $old_req_uri = $_SERVER['REQUEST_URI'];
 
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 add_filter( 'home_url', array( $this, '_get_pagenum_link_cb' ) );
                 $_SERVER['REQUEST_URI'] = '/woohoo';
                 $paged                  = get_pagenum_link( 2 );
@@ -31 +29 @@
                 $post_id2 = self::factory()->post->create();
 
                 // Basic case
-                $this->assertEquals( get_permalink( $post_id ), wp_get_shortlink( $post_id, 'post' ) );
+                $this->assertEquals( home_url( '?p=' . $post_id ), wp_get_shortlink( $post_id, 'post' ) );
 
                 unset( $GLOBALS['post'] );
 
@@ -43 +41 @@
                 $GLOBALS['post'] = get_post( $post_id );
 
                 // Global post is set
-                $this->assertEquals( get_permalink( $post_id ), wp_get_shortlink( 0, 'post' ) );
-                $this->assertEquals( get_permalink( $post_id ), wp_get_shortlink( 0 ) );
-                $this->assertEquals( get_permalink( $post_id ), wp_get_shortlink() );
+                $this->assertEquals( home_url( '?p=' . $post_id ), wp_get_shortlink( 0, 'post' ) );
+                $this->assertEquals( home_url( '?p=' . $post_id ), wp_get_shortlink( 0 ) );
+                $this->assertEquals( home_url( '?p=' . $post_id ), wp_get_shortlink() );
 
                 // Not the global post
-                $this->assertEquals( get_permalink( $post_id2 ), wp_get_shortlink( $post_id2, 'post' ) );
+                $this->assertEquals( home_url( '?p=' . $post_id2 ), wp_get_shortlink( $post_id2, 'post' ) );
 
                 unset( $GLOBALS['post'] );
 
@@ -57 +55 @@
                 $this->assertEquals( '', wp_get_shortlink( 0 ) );
                 $this->assertEquals( '', wp_get_shortlink() );
 
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 // With a permalink structure set, get_permalink() will no longer match.
                 $this->assertNotEquals( get_permalink( $post_id ), wp_get_shortlink( $post_id, 'post' ) );
                 $this->assertEquals( home_url( '?p=' . $post_id ), wp_get_shortlink( $post_id, 'post' ) );
@@ -73 +69 @@
         function test_wp_get_shortlink_with_page() {
                 $post_id = self::factory()->post->create( array( 'post_type' => 'page' ) );
 
-                // Basic case
-                // Don't test against get_permalink() since it uses ?page_id= for pages.
-                $this->assertEquals( home_url( '?p=' . $post_id ), wp_get_shortlink( $post_id, 'post' ) );
-
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 $this->assertEquals( home_url( '?p=' . $post_id ), wp_get_shortlink( $post_id, 'post' ) );
         }
 
@@ -91 +81 @@
                 update_option( 'page_on_front', $post_id );
 
                 $this->assertEquals( home_url( '/' ), wp_get_shortlink( $post_id, 'post' ) );
-
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
-                $this->assertEquals( home_url( '/' ), wp_get_shortlink( $post_id, 'post' ) );
         }
 
         /**
          * @ticket 30910
          */
         public function test_get_permalink_should_not_reveal_post_name_for_post_with_post_status_future() {
-                update_option( 'permalink_structure', '/%year%/%monthnum%/%day%/%postname%/' );
-
-                flush_rewrite_rules();
-
                 $p = self::factory()->post->create(
                         array(
                                 'post_status' => 'publish',
@@ -121 +103 @@
          * @ticket 30910
          */
         public function test_get_permalink_should_not_reveal_post_name_for_cpt_with_post_status_future() {
-                update_option( 'permalink_structure', '/%year%/%monthnum%/%day%/%postname%/' );
-
                 register_post_type( 'wptests_pt', array( 'public' => true ) );
 
                 flush_rewrite_rules();
@@ -171 +151 @@
         public function test_attachment_attached_to_non_existent_post_type_has_a_pretty_permalink() {
                 global $wp_post_types;
 
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 register_post_type( 'not_a_post_type', array( 'public' => true ) );
 
-                flush_rewrite_rules();
-
                 $post_id = self::factory()->post->create( array( 'post_type' => 'not_a_post_type' ) );
 
                 $attachment_id = self::factory()->attachment->create_object(

tests/phpunit/tests/link/getAdjacentPostLink.php

@@ -5 +5 @@
  */
 class Tests_Link_GetAdjacentPostLink extends WP_UnitTestCase {
 
-        protected $post_ids;
+        protected $posts;
         protected $cat_id;
 
         public function setUp() {
                 parent::setUp();
                 $this->cat_id     = self::factory()->category->create( array( 'name' => 'other' ) );
-                $this->post_ids   = array();
-                $this->post_ids[] = self::factory()->post->create(
+                $this->posts   = array();
+                $this->posts[] = self::factory()->post->create_and_get(
                         array(
                                 'post_type'   => 'post',
                                 'post_date'   => '2014-10-26 05:32:29',
                                 'category_id' => 1,
                         )
                 );
-                $this->post_ids[] = self::factory()->post->create(
+                $this->posts[] = self::factory()->post->create_and_get(
                         array(
                                 'post_type'   => 'post',
                                 'post_date'   => '2014-10-26 04:32:29',
                                 'category_id' => $this->cat_id,
                         )
                 );
-                $this->post_ids[] = self::factory()->post->create(
+                $this->posts[] = self::factory()->post->create_and_get(
                         array(
                                 'post_type'   => 'post',
                                 'post_date'   => '2014-10-26 03:32:29',
                                 'category_id' => 1,
                         )
                 );
-                $this->post_ids[] = self::factory()->post->create(
+                $this->posts[] = self::factory()->post->create_and_get(
                         array(
                                 'post_type'   => 'post',
                                 'post_date'   => '2014-10-26 02:32:29',
                                 'category_id' => $this->cat_id,
                         )
                 );
-                $this->post_ids[] = self::factory()->post->create(
+                $this->posts[] = self::factory()->post->create_and_get(
                         array(
                                 'post_type'   => 'post',
                                 'post_date'   => '2014-10-26 01:32:29',
@@ -50 +50 @@
 
                 //set current post (has 2 on each end)
                 global $GLOBALS;
-                $GLOBALS['post'] = get_post( $this->post_ids[2] );
+                $GLOBALS['post'] = $this->posts[2];
         }
 
         public function test_get_next_post_link_default() {
-                $actual   = get_next_post_link();
-                $title    = get_post( $this->post_ids[1] )->post_title;
-                $expected = '<a href="' . home_url( '?p=' . $this->post_ids[1] ) . '" rel="next">' . $title . '</a> &raquo;';
-                $this->assertSame( $expected, $actual );
+                $this->assertSame(
+                        '<a href="' .  get_permalink( $this->posts[1] ) . '" rel="next">' . $this->posts[1]->post_title . '</a> &raquo;',
+                        get_next_post_link()
+                );
         }
 
         public function test_get_previous_post_link_default() {
-                $actual   = get_previous_post_link();
-                $title    = get_post( $this->post_ids[3] )->post_title;
-                $expected = '&laquo; <a href="' . home_url( '?p=' . $this->post_ids[3] ) . '" rel="prev">' . $title . '</a>';
-                $this->assertSame( $expected, $actual );
+                $this->assertSame(
+                        '&laquo; <a href="' . get_permalink( $this->posts[3] ) . '" rel="prev">' . $this->posts[3]->post_title  . '</a>',
+                        get_previous_post_link()
+                );
         }
 
         public function test_get_next_post_link_same_category() {
-                $actual   = get_next_post_link( '%link &raquo;', '%title', true );
-                $title    = get_post( $this->post_ids[1] )->post_title;
-                $expected = '<a href="' . home_url( '?p=' . $this->post_ids[1] ) . '" rel="next">' . $title . '</a> &raquo;';
-                $this->assertSame( $expected, $actual );
+                $this->assertSame(
+                        '<a href="' .  get_permalink( $this->posts[1] ) . '" rel="next">' . $this->posts[1]->post_title . '</a> &raquo;',
+                        get_next_post_link( '%link &raquo;', '%title', true )
+                );
         }
 
         public function test_get_previous_post_link_same_category() {
-                $actual   = get_previous_post_link( '&laquo; %link', '%title', true );
-                $title    = get_post( $this->post_ids[3] )->post_title;
-                $expected = '&laquo; <a href="' . home_url( '?p=' . $this->post_ids[3] ) . '" rel="prev">' . $title . '</a>';
-                $this->assertSame( $expected, $actual );
+                $this->assertSame(
+                        '&laquo; <a href="' . get_permalink( $this->posts[3] ) . '" rel="prev">' . $this->posts[3]->post_title  . '</a>',
+                        get_previous_post_link( '&laquo; %link', '%title', true )
+                );
         }
 
         public function test_get_next_post_link_exclude_category() {
-                $actual   = get_next_post_link( '%link &raquo;', '%title', false, $this->cat_id );
-                $title    = get_post( $this->post_ids[1] )->post_title;
-                $expected = '<a href="' . home_url( '?p=' . $this->post_ids[1] ) . '" rel="next">' . $title . '</a> &raquo;';
-                $this->assertSame( $expected, $actual );
+                $this->assertSame(
+                        '<a href="' .  get_permalink( $this->posts[1] ) . '" rel="next">' . $this->posts[1]->post_title . '</a> &raquo;',
+                        get_next_post_link( '%link &raquo;', '%title', false, $this->cat_id )
+                );
+
         }
 
         public function test_get_previous_post_link_exclude_category() {
-                $actual   = get_previous_post_link( '&laquo; %link', '%title', false, $this->cat_id );
-                $title    = get_post( $this->post_ids[3] )->post_title;
-                $expected = '&laquo; <a href="' . home_url( '?p=' . $this->post_ids[3] ) . '" rel="prev">' . $title . '</a>';
-                $this->assertSame( $expected, $actual );
+                $this->assertSame(
+                        '&laquo; <a href="' . get_permalink( $this->posts[3] ) . '" rel="prev">' . $this->posts[3]->post_title  . '</a>',
+                        get_previous_post_link( '&laquo; %link', '%title', false, $this->cat_id )
+                );
         }
 }

tests/phpunit/tests/link/getNextCommentsLink.php

@@ -16 +16 @@
 
                 $link = get_next_comments_link( 'Next', 5 );
 
-                $this->assertContains( 'cpage=4', $link );
+                $this->assertContains( 'comment-page-4', $link );
 
                 set_query_var( 'cpage', $cpage );
         }
@@ -33 +33 @@
 
                 $link = get_next_comments_link( 'Next', 5 );
 
-                $this->assertContains( 'cpage=2', $link );
+                $this->assertContains( 'comment-page-2', $link );
 
                 set_query_var( 'cpage', $cpage );
         }

tests/phpunit/tests/link/getPostCommentsFeedLink.php

@@ -5 +5 @@
 class Tests_Link_GetPostCommentsFeedLink extends WP_UnitTestCase {
 
         public function test_post_link() {
+                tests_set_and_flush_permalinks( '' );
+
                 $post_id = self::factory()->post->create();
 
                 $link     = get_post_comments_feed_link( $post_id );
@@ -16 +18 @@
                 );
 
                 $this->assertEquals( $expected, $link );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_post_pretty_link() {
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 $post_id = self::factory()->post->create();
 
                 $link     = get_post_comments_feed_link( $post_id );
@@ -30 +32 @@
         }
 
         public function test_attachment_link() {
+                tests_set_and_flush_permalinks( '' );
+
                 $post_id       = self::factory()->post->create();
                 $attachment_id = self::factory()->attachment->create_object(
                         'image.jpg', $post_id, array(
@@ -47 +51 @@
                 );
 
                 $this->assertEquals( $expected, $link );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_attachment_pretty_link() {
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 $post_id       = self::factory()->post->create(
                         array(
                                 'post_status' => 'publish',
@@ -74 +78 @@
         }
 
         public function test_attachment_no_name_pretty_link() {
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 $post_id       = self::factory()->post->create();
                 $attachment_id = self::factory()->attachment->create_object(
                         'image.jpg', $post_id, array(
@@ -91 +93 @@
         }
 
         public function test_unattached_link() {
+                tests_set_and_flush_permalinks( '' );
+
                 $attachment_id = self::factory()->attachment->create_object(
                         'image.jpg', 0, array(
                                 'post_mime_type' => 'image/jpeg',
@@ -107 +111 @@
                 );
 
                 $this->assertEquals( $expected, $link );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_unattached_pretty_link() {
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 $attachment_id = self::factory()->attachment->create_object(
                         'image.jpg', 0, array(
                                 'post_mime_type' => 'image/jpeg',

tests/phpunit/tests/link/getPreviousCommentsLink.php

@@ -16 +16 @@
 
                 $link = get_previous_comments_link( 'Next' );
 
-                $this->assertContains( 'cpage=2', $link );
+                $this->assertContains( 'comment-page-2', $link );
 
                 set_query_var( 'cpage', $cpage );
         }

tests/phpunit/tests/link/wpGetCanonicalURL.php

@@ -16 +16 @@
                 );
         }
 
+        public static function wpTearDownAfterClass() {
+                tests_reset_and_flush_permalinks();
+        }
+
         /**
          * Test for a non existing post.
          */
@@ -47 +51 @@
          * Test non permalink structure page usage.
          */
         public function test_paged_with_plain_permalink_structure() {
+                tests_set_and_flush_permalinks( '' );
+
                 $link = add_query_arg(
                         array(
                                 'page' => 2,
@@ -63 +69 @@
                 );
 
                 $this->assertEquals( $expected, wp_get_canonical_url( self::$post_id ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -70 +78 @@
          */
         public function test_paged_with_custom_permalink_structure() {
                 $this->set_permalink_structure( '/%postname%/' );
+
                 $page = 2;
 
                 $link = add_query_arg(
@@ -84 +93 @@
                 $expected = trailingslashit( get_permalink( self::$post_id ) ) . user_trailingslashit( $page, 'single_paged' );
 
                 $this->assertEquals( $expected, wp_get_canonical_url( self::$post_id ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          *  Test non permalink structure comment page usage.
          */
         public function test_comments_paged_with_plain_permalink_structure() {
+                tests_set_and_flush_permalinks( '' );
+
                 $cpage = 2;
 
                 $link = add_query_arg(
@@ -108 +121 @@
                 );
 
                 $this->assertEquals( $expected, wp_get_canonical_url( self::$post_id ) );
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -116 +130 @@
         public function test_comments_paged_with_pretty_permalink_structure() {
                 global $wp_rewrite;
 
-                $this->set_permalink_structure( '/%postname%/' );
                 $cpage = 2;
 
                 $link = add_query_arg(

tests/phpunit/tests/oembed/controller.php

@@ -446 +446 @@
         }
 
         function test_get_oembed_endpoint_url() {
+                tests_set_and_flush_permalinks( '' );
+
                 $this->assertEquals( home_url() . '/index.php?rest_route=/oembed/1.0/embed', get_oembed_endpoint_url() );
                 $this->assertEquals( home_url() . '/index.php?rest_route=/oembed/1.0/embed', get_oembed_endpoint_url( '', 'json' ) );
                 $this->assertEquals( home_url() . '/index.php?rest_route=/oembed/1.0/embed', get_oembed_endpoint_url( '', 'xml' ) );
@@ -456 +458 @@
 
                 $this->assertEquals( home_url() . '/index.php?rest_route=%2Foembed%2F1.0%2Fembed&url=' . $url_encoded, get_oembed_endpoint_url( $url ) );
                 $this->assertEquals( home_url() . '/index.php?rest_route=%2Foembed%2F1.0%2Fembed&url=' . $url_encoded . '&format=xml', get_oembed_endpoint_url( $url, 'xml' ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         function test_get_oembed_endpoint_url_pretty_permalinks() {
-                update_option( 'permalink_structure', '/%postname%' );
-
                 $this->assertEquals( home_url() . '/wp-json/oembed/1.0/embed', get_oembed_endpoint_url() );
                 $this->assertEquals( home_url() . '/wp-json/oembed/1.0/embed', get_oembed_endpoint_url( '', 'xml' ) );
 
@@ -470 +472 @@
 
                 $this->assertEquals( home_url() . '/wp-json/oembed/1.0/embed?url=' . $url_encoded, get_oembed_endpoint_url( $url ) );
                 $this->assertEquals( home_url() . '/wp-json/oembed/1.0/embed?url=' . $url_encoded . '&format=xml', get_oembed_endpoint_url( $url, 'xml' ) );
-
-                update_option( 'permalink_structure', '' );
         }
 
         public function test_proxy_without_permission() {

tests/phpunit/tests/oembed/postEmbedUrl.php

@@ -10 +10 @@
         }
 
         function test_with_pretty_permalinks() {
-                $this->set_permalink_structure( '/%postname%' );
-
                 $post_id   = self::factory()->post->create();
                 $permalink = get_permalink( $post_id );
                 $embed_url = get_post_embed_url( $post_id );
 
-                $this->assertEquals( $permalink . '/embed', $embed_url );
+                $this->assertEquals( $permalink . 'embed/', $embed_url );
         }
 
         function test_with_ugly_permalinks() {
+                tests_set_and_flush_permalinks( '' );
+
                 $post_id   = self::factory()->post->create();
                 $permalink = get_permalink( $post_id );
                 $embed_url = get_post_embed_url( $post_id );
 
                 $this->assertEquals( $permalink . '&embed=true', $embed_url );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -43 +45 @@
                 $this->assertSame( user_trailingslashit( trailingslashit( home_url() ) . 'embed' ), $embed_url );
 
                 update_option( 'show_on_front', 'posts' );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 34971
          */
         function test_static_front_page_with_ugly_permalinks() {
+                tests_set_and_flush_permalinks( '' );
+
                 $post_id = self::factory()->post->create( array( 'post_type' => 'page' ) );
 
                 update_option( 'show_on_front', 'page' );
@@ -59 +65 @@
                 $this->assertSame( trailingslashit( home_url() ) . '?embed=true', $embed_url );
 
                 update_option( 'show_on_front', 'posts' );
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 34971
          */
         function test_page_conflicts_with_embed_slug() {
-                $this->set_permalink_structure( '/%postname%/' );
-
                 $parent_page = self::factory()->post->create( array( 'post_type' => 'page' ) );
 
                 add_filter( 'wp_unique_post_slug', array( $this, 'filter_unique_post_slug' ) );
@@ -87 +92 @@
          * @ticket 34971
          */
         function test_static_front_page_conflicts_with_embed_slug() {
-                $this->set_permalink_structure( '/%postname%/' );
-
                 // Create a post with the 'embed' post_name
                 add_filter( 'wp_unique_post_slug', array( $this, 'filter_unique_post_slug' ) );
                 $post_embed_slug = self::factory()->post->create( array( 'post_name' => 'embed' ) );
@@ -98 +101 @@
                 update_option( 'show_on_front', 'page' );
                 update_option( 'page_on_front', $page_front );
 
-                $this->assertSame( home_url() . '/embed/embed/', get_post_embed_url( $post_embed_slug ) );
+                $expected = home_url() . '/' . tests_add_blog_permalink_prefix_on_multisite( date( 'Y/m/d', time() ) . '/embed/embed/' );
+
+                $this->assertSame( $expected, get_post_embed_url( $post_embed_slug ) );
                 $this->assertSame( home_url() . '/?embed=true', get_post_embed_url( $page_front ) );
 
                 update_option( 'show_on_front', 'posts' );

tests/phpunit/tests/oembed/template.php

@@ -106 +106 @@
                 $this->assertNotFalse( strpos( $actual, 'canola.jpg' ) );
         }
 
+        /**
+         * This tests fails with pretty permalinks enabled, see #42733.
+         */
         function test_oembed_output_draft_post() {
+                tests_set_and_flush_permalinks( '' );
+
                 $post_id = self::factory()->post->create(
                         array(
                                 'post_title'   => 'Hello World',
@@ -127 +132 @@
                 $doc = new DOMDocument();
                 $this->assertTrue( $doc->loadHTML( $actual ) );
                 $this->assertNotFalse( strpos( $actual, 'That embed can’t be found.' ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
+        /**
+         * This tests fails with pretty permalinks enabled, see #42733.
+         */
         function test_oembed_output_scheduled_post() {
+                tests_set_and_flush_permalinks( '' );
+
                 $post_id = self::factory()->post->create(
                         array(
                                 'post_title'   => 'Hello World',
@@ -151 +163 @@
                 $doc = new DOMDocument();
                 $this->assertTrue( $doc->loadHTML( $actual ) );
                 $this->assertNotFalse( strpos( $actual, 'That embed can’t be found.' ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         function test_oembed_output_private_post() {

tests/phpunit/tests/oembed/wpOembed.php

@@ -159 +159 @@
          * @group ms-required
          */
         public function test_wp_filter_pre_oembed_result_multisite_sub_main() {
+                // This test fails with pretty permalinks enabled.
+                tests_set_and_flush_permalinks( '' );
+
                 $post_id   = self::factory()->post->create();
                 $permalink = get_permalink( $post_id );
                 $user_id   = self::factory()->user->create();
@@ -178 +181 @@
 
                 $this->assertNotNull( $this->pre_oembed_result_filtered );
                 $this->assertEquals( $this->pre_oembed_result_filtered, $actual );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**

tests/phpunit/tests/option/sanitize-option.php

@@ -145 +145 @@
         }
 
         public function permalink_structure_provider() {
+                $default_permalink_structure = get_option( 'permalink_structure' );
+
                 return array(
                         array( '', '', true ),
-                        array( '%postname', false, false ),
-                        array( '%/%', false, false ),
-                        array( '%%%', false, false ),
+                        array( '%postname', $default_permalink_structure, false ),
+                        array( '%/%', $default_permalink_structure, false ),
+                        array( '%%%', $default_permalink_structure, false ),
                         array( '%a%', '%a%', true ),
                         array( '%postname%', '%postname%', true ),
                         array( '/%postname%/', '/%postname%/', true ),

tests/phpunit/tests/post.php

@@ -434 +434 @@
          * @ticket 5305
          */
         public function test_wp_insert_post_should_not_allow_a_bare_numeric_slug_that_might_conflict_with_a_date_archive_when_generating_from_an_empty_post_title() {
+
                 $this->set_permalink_structure( '/%postname%/' );
 
                 $p = wp_insert_post(
@@ -447 +448 @@
 
                 $post = get_post( $p );
 
-                $this->set_permalink_structure();
-
                 $this->assertEquals( "$p-2", $post->post_name );
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -469 +469 @@
 
                 $post = get_post( $p );
 
-                $this->assertContains( 'wptests_pt=' . $p, $post->guid );
+                $this->assertContains( 'wptests_pt/' . $p, $post->guid );
         }
 
         /**
@@ -526 +526 @@
         function test_permalink_without_title() {
                 // bug: permalink doesn't work if post title is empty
                 // might only fail if the post ID is greater than four characters
-
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 $post = array(
                         'post_author'  => self::$editor_id,
                         'post_status'  => 'publish',
@@ -543 +540 @@
                 $plink = get_permalink( $id );
 
                 // permalink should include the post ID at the end
-                $this->assertEquals( get_option( 'siteurl' ) . '/2007/10/31/' . $id . '/', $plink );
+                $this->assertEquals(
+                        get_option( 'siteurl' ) . '/' . tests_add_blog_permalink_prefix_on_multisite( '2007/10/31/' . $id . '/' ),
+                        $plink
+                );
         }
 
         /**

tests/phpunit/tests/post/nav-menu.php

@@ -687 +687 @@
          * @ticket 39800
          */
         function test_parent_ancestor_for_post_archive() {
+                // This test only works without pretty permalinks.
+                tests_set_and_flush_permalinks( '' );
 
                 register_post_type(
                         'books', array(
@@ -760 +762 @@
 
                 $this->assertNotContains( 'current-menu-parent', $post_archive_menu_item->classes );
                 $this->assertNotContains( 'current-menu-ancestor', $post_archive_menu_item->classes );
+
+                tests_reset_and_flush_permalinks();
         }
 
 }

tests/phpunit/tests/post/types.php

@@ -313 +313 @@
          * @ticket 14761
          */
         public function test_unregister_post_type_removes_rewrite_tags() {
-                $this->set_permalink_structure( '/%postname%' );
-
                 global $wp_rewrite;
 
                 register_post_type(
@@ -338 +336 @@
          * @ticket 14761
          */
         public function test_unregister_post_type_removes_rewrite_rules() {
-                $this->set_permalink_structure( '/%postname%' );
-
                 global $wp_rewrite;
 
                 register_post_type(

tests/phpunit/tests/post/wpPostType.php

@@ -60 +60 @@
         }
 
         public function test_does_not_add_query_var_if_not_public() {
-                $this->set_permalink_structure( '/%postname%' );
-
                 /* @var WP $wp */
                 global $wp;
 
@@ -78 +76 @@
         }
 
         public function test_adds_query_var_if_public() {
-                $this->set_permalink_structure( '/%postname%' );
-
                 /* @var WP $wp */
                 global $wp;
 
@@ -103 +99 @@
         }
 
         public function test_adds_rewrite_rules() {
-                $this->set_permalink_structure( '/%postname%' );
-
                 /* @var WP_Rewrite $wp_rewrite */
                 global $wp_rewrite;
 

tests/phpunit/tests/post/wpUniquePostSlug.php

@@ -179 +179 @@
          * @ticket 5305
          */
         public function test_slugs_resulting_in_permalinks_that_resemble_year_archives_should_be_suffixed() {
+
                 $this->set_permalink_structure( '/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -190 +191 @@
 
                 $found = wp_unique_post_slug( '2015', $p, 'publish', 'post', 0 );
                 $this->assertEquals( '2015-2', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 5305
          */
         public function test_slugs_resulting_in_permalinks_that_resemble_year_archives_should_not_be_suffixed_for_already_published_posts() {
+
                 $this->set_permalink_structure( '/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -208 +212 @@
 
                 $found = wp_unique_post_slug( '2015', $p, 'publish', 'post', 0 );
                 $this->assertEquals( '2015-2', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 5305
          */
         public function test_yearlike_slugs_should_not_be_suffixed_if_permalink_structure_does_not_result_in_a_clash_with_year_archives() {
+
                 $this->set_permalink_structure( '/%year%/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -225 +232 @@
 
                 $found = wp_unique_post_slug( '2015', $p, 'publish', 'post', 0 );
                 $this->assertEquals( '2015', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 5305
          */
         public function test_slugs_resulting_in_permalinks_that_resemble_month_archives_should_be_suffixed() {
+
                 $this->set_permalink_structure( '/%year%/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -242 +252 @@
 
                 $found = wp_unique_post_slug( '11', $p, 'publish', 'post', 0 );
                 $this->assertEquals( '11-2', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 5305
          */
         public function test_monthlike_slugs_should_not_be_suffixed_if_permalink_structure_does_not_result_in_a_clash_with_month_archives() {
+
                 $this->set_permalink_structure( '/%year%/foo/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -259 +272 @@
 
                 $found = wp_unique_post_slug( '11', $p, 'publish', 'post', 0 );
                 $this->assertEquals( '11', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 5305
          */
         public function test_monthlike_slugs_should_not_be_suffixed_for_invalid_month_numbers() {
+
                 $this->set_permalink_structure( '/%year%/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -276 +292 @@
 
                 $found = wp_unique_post_slug( '13', $p, 'publish', 'post', 0 );
                 $this->assertEquals( '13', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 5305
          */
         public function test_slugs_resulting_in_permalinks_that_resemble_day_archives_should_be_suffixed() {
+
                 $this->set_permalink_structure( '/%year%/%monthnum%/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -293 +312 @@
 
                 $found = wp_unique_post_slug( '30', $p, 'publish', 'post', 0 );
                 $this->assertEquals( '30-2', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 5305
          */
         public function test_daylike_slugs_should_not_be_suffixed_if_permalink_structure_does_not_result_in_a_clash_with_day_archives() {
+
                 $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -310 +332 @@
 
                 $found = wp_unique_post_slug( '30', $p, 'publish', 'post', 0 );
                 $this->assertEquals( '30', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 5305
          */
         public function test_daylike_slugs_should_not_be_suffixed_for_invalid_day_numbers() {
+
                 $this->set_permalink_structure( '/%year%/%monthnum%/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -327 +352 @@
 
                 $found = wp_unique_post_slug( '32', $p, 'publish', 'post', 0 );
                 $this->assertEquals( '32', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 34971
          */
         public function test_embed_slug_should_be_suffixed_for_posts() {
+
                 $this->set_permalink_structure( '/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -344 +372 @@
 
                 $found = wp_unique_post_slug( 'embed', $p, 'publish', 'post', 0 );
                 $this->assertSame( 'embed-2', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 34971
          */
         public function test_embed_slug_should_be_suffixed_for_pages() {
+
                 $this->set_permalink_structure( '/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -361 +392 @@
 
                 $found = wp_unique_post_slug( 'embed', $p, 'publish', 'paage', 0 );
                 $this->assertSame( 'embed-2', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 34971
          */
         public function test_embed_slug_should_be_suffixed_for_attachments() {
+
                 $this->set_permalink_structure( '/%postname%/' );
 
                 $p = self::factory()->post->create(
@@ -378 +412 @@
 
                 $found = wp_unique_post_slug( 'embed', $p, 'publish', 'attachment', 0 );
                 $this->assertSame( 'embed-2', $found );
+
+                tests_reset_and_flush_permalinks();
         }
 }

tests/phpunit/tests/query.php

@@ -5 +5 @@
         function setUp() {
                 parent::setUp();
 
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
                 create_initial_taxonomies();
         }
 

tests/phpunit/tests/query/conditionals.php

@@ -22 +22 @@
                 update_option( 'comments_per_page', 5 );
                 update_option( 'posts_per_page', 5 );
 
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 create_initial_taxonomies();
         }
 
@@ -490 +488 @@
                 // check the long form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                        $this->go_to( "/category/cat-a/feed/{$type}" );
+                        $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "category/cat-a/feed/{$type}" ) );
                         $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_category' );
                 }
 
                 // check the short form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                        $this->go_to( "/category/cat-a/{$type}" );
+                        $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "category/cat-a/{$type}" ) );
                         $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_category' );
                 }
         }
@@ -506 +504 @@
         function test_category_paged() {
                 update_option( 'posts_per_page', 2 );
                 self::factory()->post->create_many( 3 );
-                $this->go_to( '/category/uncategorized/page/2/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( 'category/uncategorized/page/2/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_category', 'is_paged' );
         }
 
@@ -518 +516 @@
                                 'taxonomy' => 'category',
                         )
                 );
-                $this->go_to( '/category/cat-a/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( 'category/cat-a/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_category' );
         }
 
@@ -534 +532 @@
                 // check the long form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                                $this->go_to( "/tag/tag-a/feed/{$type}" );
+                                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "tag/tag-a/feed/{$type}" ) );
                                 $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_tag' );
                 }
 
                 // check the short form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                                $this->go_to( "/tag/tag-a/{$type}" );
+                                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "tag/tag-a/{$type}" ) );
                                 $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_tag' );
                 }
         }
@@ -553 +551 @@
                 foreach ( $post_ids as $post_id ) {
                         self::factory()->term->add_post_terms( $post_id, 'tag-a', 'post_tag' );
                 }
-                $this->go_to( '/tag/tag-a/page/2/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( 'tag/tag-a/page/2/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_tag', 'is_paged' );
         }
 
@@ -566 +564 @@
                                 'taxonomy' => 'post_tag',
                         )
                 );
-                $this->go_to( '/tag/tag-a/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( 'tag/tag-a/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_tag' );
 
                 $tag = get_term( $term_id, 'post_tag' );
@@ -588 +586 @@
                 // check the long form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                                $this->go_to( "/author/user-a/feed/{$type}" );
+                                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "author/user-a/feed/{$type}" ) );
                                 $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_author' );
                 }
 
                 // check the short form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                                $this->go_to( "/author/user-a/{$type}" );
+                                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "author/user-a/{$type}" ) );
                                 $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_author' );
                 }
         }
@@ -605 +603 @@
                 update_option( 'posts_per_page', 2 );
                 $user_id = self::factory()->user->create( array( 'user_login' => 'user-a' ) );
                 self::factory()->post->create_many( 3, array( 'post_author' => $user_id ) );
-                $this->go_to( '/author/user-a/page/2/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( 'author/user-a/page/2/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_author', 'is_paged' );
         }
 
@@ -613 +611 @@
         function test_author() {
                 $user_id = self::factory()->user->create( array( 'user_login' => 'user-a' ) );
                 self::factory()->post->create( array( 'post_author' => $user_id ) );
-                $this->go_to( '/author/user-a/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( 'author/user-a/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_author' );
         }
 
         function test_author_with_no_posts() {
                 $user_id = self::factory()->user->create( array( 'user_login' => 'user-a' ) );
-                $this->go_to( '/author/user-a/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( 'author/user-a/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_author' );
         }
 
@@ -630 +628 @@
                 // check the long form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                                $this->go_to( "/2007/09/04/feed/{$type}" );
+                                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "2007/09/04/feed/{$type}" ) );
                                 $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_day', 'is_date' );
                 }
 
                 // check the short form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                                $this->go_to( "/2007/09/04/{$type}" );
+                                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "2007/09/04/{$type}" ) );
                                 $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_day', 'is_date' );
                 }
         }
@@ -646 +644 @@
         function test_ymd_paged() {
                 update_option( 'posts_per_page', 2 );
                 self::factory()->post->create_many( 3, array( 'post_date' => '2007-09-04 00:00:00' ) );
-                $this->go_to( '/2007/09/04/page/2/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( '2007/09/04/page/2/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_day', 'is_date', 'is_paged' );
         }
 
         // '([0-9]{4})/([0-9]{1,2})/([0-9]{1,2})/?$' => 'index.php?year=$matches[1]&monthnum=$matches[2]&day=$matches[3]',
         function test_ymd() {
                 self::factory()->post->create( array( 'post_date' => '2007-09-04 00:00:00' ) );
-                $this->go_to( '/2007/09/04/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( '2007/09/04/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_day', 'is_date' );
         }
 
@@ -664 +662 @@
                 // check the long form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                                $this->go_to( "/2007/09/feed/{$type}" );
+                                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "2007/09/feed/{$type}" ) );
                                 $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_month', 'is_date' );
                 }
 
                 // check the short form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                                $this->go_to( "/2007/09/{$type}" );
+                                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "2007/09/{$type}" ) );
                                 $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_month', 'is_date' );
                 }
         }
@@ -680 +678 @@
         function test_ym_paged() {
                 update_option( 'posts_per_page', 2 );
                 self::factory()->post->create_many( 3, array( 'post_date' => '2007-09-04 00:00:00' ) );
-                $this->go_to( '/2007/09/page/2/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( '2007/09/page/2/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_date', 'is_month', 'is_paged' );
         }
 
         // '([0-9]{4})/([0-9]{1,2})/?$' => 'index.php?year=$matches[1]&monthnum=$matches[2]',
         function test_ym() {
                 self::factory()->post->create( array( 'post_date' => '2007-09-04 00:00:00' ) );
-                $this->go_to( '/2007/09/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( '2007/09/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_date', 'is_month' );
         }
 
@@ -698 +696 @@
                 // check the long form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                                $this->go_to( "/2007/feed/{$type}" );
+                                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "2007/feed/{$type}" ) );
                                 $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_year', 'is_date' );
                 }
 
                 // check the short form
                 $types = array( 'feed', 'rdf', 'rss', 'rss2', 'atom' );
                 foreach ( $types as $type ) {
-                                $this->go_to( "/2007/{$type}" );
+                                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "2007/{$type}" ) );
                                 $this->assertQueryTrue( 'is_archive', 'is_feed', 'is_year', 'is_date' );
                 }
         }
@@ -714 +712 @@
         function test_y_paged() {
                 update_option( 'posts_per_page', 2 );
                 self::factory()->post->create_many( 3, array( 'post_date' => '2007-09-04 00:00:00' ) );
-                $this->go_to( '/2007/page/2/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( '2007/page/2/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_date', 'is_year', 'is_paged' );
         }
 
         // '([0-9]{4})/?$' => 'index.php?year=$matches[1]',
         function test_y() {
                 self::factory()->post->create( array( 'post_date' => '2007-09-04 00:00:00' ) );
-                $this->go_to( '/2007/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( '2007/' ) );
                 $this->assertQueryTrue( 'is_archive', 'is_date', 'is_year' );
         }
 
@@ -788 +786 @@
          * @expectedIncorrectUsage WP_Date_Query
          */
         function test_bad_dates() {
-                $this->go_to( '/2013/13/13/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( '2013/13/13/' ) );
                 $this->assertQueryTrue( 'is_404' );
 
-                $this->go_to( '/2013/11/41/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( '2013/11/41/' ) );
                 $this->assertQueryTrue( 'is_404' );
         }
 
@@ -812 +810 @@
                 $post_id = self::factory()->post->create( array( 'post_type' => $cpt_name ) );
                 wp_set_object_terms( $post_id, $tag_id, 'post_tag' );
 
-                $this->go_to( '/ptawtq/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( 'ptawtq/' ) );
                 $this->assertQueryTrue( 'is_post_type_archive', 'is_archive' );
                 $this->assertEquals( get_queried_object(), get_post_type_object( $cpt_name ) );
 
                 add_action( 'pre_get_posts', array( $this, 'pre_get_posts_with_tax_query' ) );
 
-                $this->go_to( '/ptawtq/' );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( 'ptawtq/' ) );
                 $this->assertQueryTrue( 'is_post_type_archive', 'is_archive' );
                 $this->assertEquals( get_queried_object(), get_post_type_object( $cpt_name ) );
 
@@ -852 +850 @@
                 );
                 self::factory()->post->create( array( 'post_type' => $cpt_name ) );
 
-                $this->go_to( "/$cpt_name/" );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "$cpt_name/" ) );
                 $this->assertQueryTrue( 'is_post_type_archive', 'is_archive' );
                 $this->assertEquals( get_queried_object(), get_post_type_object( $cpt_name ) );
 
                 add_action( 'pre_get_posts', array( $this, 'pre_get_posts_with_type_array' ) );
 
-                $this->go_to( "/$cpt_name/" );
+                $this->go_to( tests_add_blog_permalink_prefix_on_multisite( "$cpt_name/" ) );
                 $this->assertQueryTrue( 'is_post_type_archive', 'is_archive' );
                 $this->assertEquals( get_queried_object(), get_post_type_object( 'post' ) );
 
@@ -966 +964 @@
          * @ticket 24612
          */
         public function test_is_single_with_slug_that_clashes_with_attachment() {
+
                 $this->set_permalink_structure( '/%postname%/' );
 
                 $attachment_id = $this->factory->post->create(
@@ -989 +988 @@
                 $this->assertFalse( $q->is_attachment() );
                 $this->assertFalse( $q->is_404() );
 
-                $this->set_permalink_structure();
+                tests_reset_and_flush_permalinks();
         }
 
         /**

tests/phpunit/tests/query/isTerm.php

@@ -30 +30 @@
                 $GLOBALS['wp_the_query'] = new WP_Query();
                 $GLOBALS['wp_query']     = $GLOBALS['wp_the_query'];
 
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 create_initial_taxonomies();
                 register_taxonomy( 'testtax', 'post', array( 'public' => true ) );
 
@@ -78 +76 @@
 
         function test_tag_action_tax() {
                 // tag with tax added
-                $this->go_to( home_url( '/tag/tag-slug/' ) );
+                $this->go_to( home_url( tests_add_blog_permalink_prefix_on_multisite( '/tag/tag-slug/' ) ) );
                 $this->assertQueryTrue( 'is_tag', 'is_archive' );
                 $this->assertNotEmpty( get_query_var( 'tax_query' ) );
                 $this->assertNotEmpty( get_query_var( 'taxonomy' ) );
@@ -89 +87 @@
 
         function test_tag_query_cat_action_tax() {
                 // tag + category with tax added
-                $this->go_to( home_url( "/tag/tag-slug/?cat=$this->cat_id" ) );
+                $this->go_to( home_url( tests_add_blog_permalink_prefix_on_multisite( "/tag/tag-slug/?cat=$this->cat_id" ) ) );
                 $this->assertQueryTrue( 'is_category', 'is_tag', 'is_archive' );
                 $this->assertNotEmpty( get_query_var( 'tax_query' ) );
                 $this->assertNotEmpty( get_query_var( 'taxonomy' ) );
@@ -101 +99 @@
 
         function test_tag_query_cat_query_tax_action_tax() {
                 // tag + category + tax with tax added
-                $this->go_to( home_url( "/tag/tag-slug/?cat=$this->cat_id&testtax=tax-slug2" ) );
+                $this->go_to( home_url( tests_add_blog_permalink_prefix_on_multisite( "/tag/tag-slug/?cat=$this->cat_id&testtax=tax-slug2" ) ) );
                 $this->assertQueryTrue( 'is_category', 'is_tag', 'is_tax', 'is_archive' );
                 $this->assertNotEmpty( get_query_var( 'tax_query' ) );
                 $this->assertNotEmpty( get_query_var( 'taxonomy' ) );
@@ -114 +112 @@
 
         function test_cat_action_tax() {
                 // category with tax added
-                $this->go_to( home_url( '/category/cat-slug/' ) );
+                $this->go_to( home_url( tests_add_blog_permalink_prefix_on_multisite( '/category/cat-slug/' ) ) );
                 $this->assertQueryTrue( 'is_category', 'is_archive' );
                 $this->assertNotEmpty( get_query_var( 'cat' ) );
                 $this->assertNotEmpty( get_query_var( 'tax_query' ) );
@@ -130 +128 @@
                 // category with tax added
                 add_action( 'pre_get_posts', array( $this, '_cat_uncat_action_tax' ), 11 );
 
-                $this->go_to( home_url( '/category/uncategorized/' ) );
+                $this->go_to( home_url( tests_add_blog_permalink_prefix_on_multisite( '/category/uncategorized/' ) ) );
                 $this->assertQueryTrue( 'is_category', 'is_archive' );
                 $this->assertNotEmpty( get_query_var( 'cat' ) );
                 $this->assertNotEmpty( get_query_var( 'tax_query' ) );
@@ -154 +152 @@
          */
         function test_tax_action_tax() {
                 // tax with tax added
-                $this->go_to( home_url( '/testtax/tax-slug2/' ) );
+                $this->go_to( home_url( tests_add_blog_permalink_prefix_on_multisite( '/testtax/tax-slug2/' ) ) );
                 $this->assertQueryTrue( 'is_tax', 'is_archive' );
                 $this->assertNotEmpty( get_query_var( 'tax_query' ) );
                 $this->assertNotEmpty( get_query_var( 'taxonomy' ) );
@@ -164 +162 @@
 
         function test_tax_query_tag_action_tax() {
                 // tax + tag with tax added
-                $this->go_to( home_url( "/testtax/tax-slug2/?tag_id=$this->tag_id" ) );
+                $this->go_to( home_url( tests_add_blog_permalink_prefix_on_multisite( "/testtax/tax-slug2/?tag_id=$this->tag_id" ) ) );
                 $this->assertQueryTrue( 'is_tag', 'is_tax', 'is_archive' );
                 $this->assertNotEmpty( get_query_var( 'tax_query' ) );
                 $this->assertNotEmpty( get_query_var( 'taxonomy' ) );
@@ -175 +173 @@
 
         function test_tax_query_cat_action_tax() {
                 // tax + cat with tax added
-                $this->go_to( home_url( "/testtax/tax-slug2/?cat=$this->cat_id" ) );
+                $this->go_to( home_url( tests_add_blog_permalink_prefix_on_multisite( "/testtax/tax-slug2/?cat=$this->cat_id" ) ) );
                 $this->assertQueryTrue( 'is_category', 'is_tax', 'is_archive' );
                 $this->assertNotEmpty( get_query_var( 'tax_query' ) );
                 $this->assertNotEmpty( get_query_var( 'taxonomy' ) );

tests/phpunit/tests/query/verboseRewriteRules.php

@@ -13 +13 @@
                 $this->set_permalink_structure( '/%category%/%year%/%postname%/' );
                 create_initial_taxonomies();
         }
+
+        public function tearDown() {
+                parent::tearDown();
+
+                tests_reset_and_flush_permalinks();
+        }
 }

tests/phpunit/tests/rest-api.php

@@ -486 +486 @@
          * whether the blog is configured with pretty permalink support or not.
          */
         public function test_rest_url_generation() {
+
+
                 // In pretty permalinks case, we expect a path of wp-json/ with no query.
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
                 $this->assertEquals( 'http://' . WP_TESTS_DOMAIN . '/wp-json/', get_rest_url() );
 
                 // In index permalinks case, we expect a path of index.php/wp-json/ with no query.
@@ -497 +498 @@
                 // In non-pretty case, we get a query string to invoke the rest router.
                 $this->set_permalink_structure( '' );
                 $this->assertEquals( 'http://' . WP_TESTS_DOMAIN . '/index.php?rest_route=/', get_rest_url() );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**

tests/phpunit/tests/rest-api/rest-posts-controller.php

@@ -2885 +2885 @@
         }
 
         public function test_update_post_with_categories() {
+                tests_set_and_flush_permalinks( '' );
 
                 wp_set_current_user( self::$editor_id );
                 $category = wp_insert_term( 'Test Category', 'category' );
@@ -2911 +2912 @@
                 }
                 $query = parse_url( $categories_path, PHP_URL_QUERY );
                 parse_str( $query, $args );
+
                 $request = new WP_REST_Request( 'GET', $args['rest_route'] );
                 unset( $args['rest_route'] );
                 $request->set_query_params( $args );
@@ -2918 +2920 @@
                 $data     = $response->get_data();
                 $this->assertCount( 1, $data );
                 $this->assertEquals( 'Test Category', $data[0]['name'] );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_update_post_with_empty_categories() {

tests/phpunit/tests/rewrite.php

@@ -11 +11 @@
         function setUp() {
                 parent::setUp();
 
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
                 create_initial_taxonomies();
 
                 $this->home_url = get_option( 'home' );
         }
 
         function tearDown() {
-                global $wp_rewrite;
-                $wp_rewrite->init();
-
                 update_option( 'home', $this->home_url );
                 parent::tearDown();
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -85 +83 @@
         }
 
         function test_url_to_postid() {
+                tests_set_and_flush_permalinks( '' );
 
                 $id = self::factory()->post->create();
                 $this->assertEquals( $id, url_to_postid( get_permalink( $id ) ) );
 
                 $id = self::factory()->post->create( array( 'post_type' => 'page' ) );
                 $this->assertEquals( $id, url_to_postid( get_permalink( $id ) ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         function test_url_to_postid_set_url_scheme_https_to_http() {
@@ -101 +102 @@
                 $post_id   = self::factory()->post->create( array( 'post_type' => 'page' ) );
                 $permalink = get_permalink( $post_id );
                 $this->assertEquals( $post_id, url_to_postid( set_url_scheme( $permalink, 'https' ) ) );
+
+
         }
 
         function test_url_to_postid_set_url_scheme_http_to_https() {
+
                 $_SERVER['HTTPS'] = 'on';
 
                 $post_id        = self::factory()->post->create();
@@ -116 +120 @@
 
                 $this->assertEquals( $post_id, $post_url_to_id );
                 $this->assertEquals( $page_id, $page_url_to_id );
+
+
         }
 
         /**
@@ -398 +404 @@
          * @ticket 21970
          */
         function test_url_to_postid_with_post_slug_that_clashes_with_a_trashed_page() {
+
                 $this->set_permalink_structure( '/%postname%/' );
 
                 $page_id = self::factory()->post->create(
@@ -409 +416 @@
                 $post_id = self::factory()->post->create( array( 'post_title' => get_post( $page_id )->post_title ) );
 
                 $this->assertEquals( $post_id, url_to_postid( get_permalink( $post_id ) ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -435 +444 @@
          * @ticket 39373
          */
         public function test_url_to_postid_should_bail_when_host_does_not_match() {
+
                 $this->set_permalink_structure( '/%postname%/' );
 
                 $post_id   = self::factory()->post->create( array( 'post_name' => 'foo-bar-baz' ) );
@@ -443 +453 @@
 
                 $this->assertSame( $post_id, url_to_postid( $permalink ) );
                 $this->assertSame( 0, url_to_postid( $url ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 21970
          */
         function test_parse_request_with_post_slug_that_clashes_with_a_trashed_page() {
+
                 $this->set_permalink_structure( '/%postname%/' );
 
                 $page_id = self::factory()->post->create(
@@ -463 +476 @@
 
                 $this->assertTrue( is_single() );
                 $this->assertFalse( is_404() );
+
+                tests_reset_and_flush_permalinks();
         }
 
         /**
          * @ticket 29107
          */
         public function test_flush_rules_does_not_delete_option() {
+
                 $this->set_permalink_structure( '' );
 
                 $rewrite_rules = get_option( 'rewrite_rules' );
                 $this->assertSame( '', $rewrite_rules );
 
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
+                tests_reset_and_flush_permalinks();
 
                 $rewrite_rules = get_option( 'rewrite_rules' );
                 $this->assertInternalType( 'array', $rewrite_rules );

tests/phpunit/tests/rewrite/addRewriteRule.php

@@ -4 +4 @@
  * @group rewrite
  */
 class Tests_Rewrite_AddRewriteRule extends WP_UnitTestCase {
-
-        public function setUp() {
-                parent::setUp();
-
-                $this->set_permalink_structure( '/%postname%/' );
-        }
-
         /**
          * @ticket 16840
          */

tests/phpunit/tests/rewrite/numericSlugs.php

@@ -48 +48 @@
                 $this->go_to( get_permalink( '2015' ) );
 
                 $this->assertQueryTrue( 'is_single', 'is_singular' );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_url_to_postid_year_segment_collision_without_title() {
@@ -76 +78 @@
                 );
 
                 $this->assertEquals( '2015', url_to_postid( get_permalink( '2015' ) ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_go_to_year_segment_collision_with_title() {
@@ -94 +98 @@
                 $this->go_to( get_permalink( $id ) );
 
                 $this->assertQueryTrue( 'is_single', 'is_singular' );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_url_to_postid_year_segment_collision_with_title() {
@@ -129 +135 @@
                 $this->go_to( get_permalink( $id ) );
 
                 $this->assertQueryTrue( 'is_single', 'is_singular' );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_url_to_postid_month_segment_collision_without_title() {
@@ -146 +154 @@
                 );
 
                 $this->assertEquals( $id, url_to_postid( get_permalink( $id ) ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_go_to_month_segment_collision_without_title_no_leading_zero() {
@@ -165 +175 @@
                 $this->go_to( get_permalink( $id ) );
 
                 $this->assertQueryTrue( 'is_single', 'is_singular' );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_url_to_postid_month_segment_collision_without_title_no_leading_zero() {
@@ -182 +194 @@
                 );
 
                 $this->assertEquals( $id, url_to_postid( get_permalink( $id ) ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_go_to_month_segment_collision_with_title() {
@@ -200 +214 @@
                 $this->go_to( get_permalink( $id ) );
 
                 $this->assertQueryTrue( 'is_single', 'is_singular' );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_url_to_postid_month_segment_collision_with_title() {
@@ -216 +232 @@
                 );
 
                 $this->assertEquals( $id, url_to_postid( get_permalink( $id ) ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_go_to_month_segment_collision_with_title_no_leading_zero() {
@@ -234 +252 @@
                 $this->go_to( get_permalink( $id ) );
 
                 $this->assertQueryTrue( 'is_single', 'is_singular' );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_url_to_postid_month_segment_collision_with_title_no_leading_zero() {
@@ -250 +270 @@
                 );
 
                 $this->assertEquals( $id, url_to_postid( get_permalink( $id ) ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_go_to_day_segment_collision_without_title() {
@@ -269 +291 @@
                 $this->go_to( get_permalink( $id ) );
 
                 $this->assertQueryTrue( 'is_single', 'is_singular' );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_url_to_postid_day_segment_collision_without_title() {
@@ -286 +310 @@
                 );
 
                 $this->assertEquals( $id, url_to_postid( get_permalink( $id ) ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_go_to_day_segment_collision_with_title() {
@@ -304 +330 @@
                 $this->go_to( get_permalink( $id ) );
 
                 $this->assertQueryTrue( 'is_single', 'is_singular' );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_url_to_postid_day_segment_collision_with_title() {
@@ -320 +348 @@
                 );
 
                 $this->assertEquals( $id, url_to_postid( get_permalink( $id ) ) );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_numeric_slug_permalink_conflicts_should_only_be_resolved_for_the_main_query() {
@@ -345 +375 @@
 
                 $this->assertTrue( $q->is_day );
                 $this->assertFalse( $q->is_single );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_month_slug_collision_should_resolve_to_date_archive_when_year_does_not_match_post_year() {
@@ -377 +409 @@
                 $this->go_to( $permalink );
 
                 $this->assertTrue( is_month() );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_day_slug_collision_should_resolve_to_date_archive_when_monthnum_does_not_match_post_month() {
@@ -409 +443 @@
                 $this->go_to( $permalink );
 
                 $this->assertTrue( is_day() );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_date_slug_collision_should_distinguish_valid_pagination_from_date() {
@@ -427 +463 @@
                 $this->go_to( get_permalink( $id ) . '1' );
 
                 $this->assertFalse( is_day() );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_date_slug_collision_should_distinguish_too_high_pagination_from_date() {
@@ -445 +483 @@
                 $this->go_to( get_permalink( $id ) . '5' );
 
                 $this->assertTrue( is_day() );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_date_slug_collision_should_not_require_pagination_query_var() {
@@ -464 +504 @@
 
                 $this->assertQueryTrue( 'is_single', 'is_singular' );
                 $this->assertFalse( is_date() );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_date_slug_collision_should_be_ignored_when_pagination_var_is_present_but_post_does_not_have_multiple_pages() {
@@ -482 +524 @@
                 $this->go_to( get_permalink( $id ) . '5' );
 
                 $this->assertTrue( is_day() );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function filter_unique_post_slug( $slug, $post_id, $post_status, $post_type, $post_parent, $original_slug ) {

tests/phpunit/tests/rewrite/oldSlugRedirect.php

@@ -21 +21 @@
 
                 add_filter( 'old_slug_redirect_url', array( $this, 'filter_old_slug_redirect_url' ), 10, 1 );
 
-                $this->set_permalink_structure( '/%postname%/' );
-
                 add_rewrite_endpoint( 'custom-endpoint', EP_PERMALINK );
                 add_rewrite_endpoint( 'second-endpoint', EP_PERMALINK, 'custom' );
 

tests/phpunit/tests/rewrite/permastructs.php

@@ -7 +7 @@
 
         public function setUp() {
                 parent::setUp();
-
-                $this->set_permalink_structure( '/%postname%/' );
         }
 
         public function test_add_permastruct() {

tests/phpunit/tests/taxonomy.php

@@ -792 +792 @@
          * @ticket 35227
          */
         public function test_unregister_taxonomy_removes_permastruct() {
-                $this->set_permalink_structure( '/%postname%' );
-
                 global $wp_rewrite;
 
                 register_taxonomy(
@@ -812 +810 @@
          * @ticket 35227
          */
         public function test_unregister_taxonomy_removes_rewrite_rules() {
-                $this->set_permalink_structure( '/%postname%' );
-
                 global $wp_rewrite;
 
                 register_taxonomy( 'foo', 'post', array( 'query_var' => 'bar' ) );

tests/phpunit/tests/term/getTermLink.php

@@ -12 +12 @@
         }
 
         public function test_integer_should_be_interpreted_as_term_id() {
+                tests_set_and_flush_permalinks( '' );
+
                 $t1 = self::factory()->term->create(
                         array(
                                 'taxonomy' => 'wptests_tax',
@@ -28 +30 @@
                 $term = intval( $t1 );
 
                 $actual = get_term_link( $term, 'wptests_tax' );
-                $this->assertContains( 'wptests_tax=foo', $actual );
+                $this->assertContains( '?wptests_tax=foo', $actual );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_numeric_string_should_be_interpreted_as_term_slug() {
+                tests_set_and_flush_permalinks( '' );
+
                 $t1 = self::factory()->term->create(
                         array(
                                 'taxonomy' => 'wptests_tax',
@@ -48 +54 @@
                 $term = (string) $t1;
 
                 $actual = get_term_link( $term, 'wptests_tax' );
-                $this->assertContains( 'wptests_tax=' . $term, $actual );
+                $this->assertContains( '?wptests_tax=' . $term, $actual );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_invalid_term_should_return_wp_error() {
@@ -57 +65 @@
         }
 
         public function test_category_should_use_cat_query_var_with_term_id() {
+                tests_set_and_flush_permalinks( '' );
+
                 $c = self::factory()->category->create();
 
                 $actual = get_term_link( $c, 'category' );
                 $this->assertContains( 'cat=' . $c, $actual );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_taxonomy_with_query_var_should_use_that_query_var_with_term_slug() {
+                tests_set_and_flush_permalinks( '' );
+
                 register_taxonomy(
                         'wptests_tax2', 'post', array(
                                 'query_var' => 'foo',
@@ -79 +93 @@
 
                 $actual = get_term_link( $t, 'wptests_tax2' );
                 $this->assertContains( 'foo=bar', $actual );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_taxonomy_without_query_var_should_use_taxonomy_query_var_and_term_query_var_with_term_slug() {
+                tests_set_and_flush_permalinks( '' );
+
                 register_taxonomy(
                         'wptests_tax2', 'post', array(
                                 'query_var' => false,
@@ -98 +116 @@
                 $actual = get_term_link( $t, 'wptests_tax2' );
                 $this->assertContains( 'taxonomy=wptests_tax2', $actual );
                 $this->assertContains( 'term=bar', $actual );
+
+                tests_reset_and_flush_permalinks();
         }
 
         public function test_taxonomy_permastruct_with_hierarchical_rewrite_should_put_term_ancestors_in_link() {
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 register_taxonomy(
                         'wptests_tax2', 'post', array(
                                 'hierarchical' => true,
@@ -136 +154 @@
         }
 
         public function test_taxonomy_permastruct_with_nonhierarchical_rewrite_should_not_put_term_ancestors_in_link() {
-                $this->set_permalink_structure( '/%year%/%monthnum%/%day%/%postname%/' );
-
                 register_taxonomy(
                         'wptests_tax2', 'post', array(
                                 'hierarchical' => true,

tests/phpunit/tests/term/wpTaxonomy.php

@@ -13 +13 @@
         }
 
         public function test_does_not_add_query_var_if_not_public() {
-                $this->set_permalink_structure( '/%postname%' );
-
                 /* @var WP $wp */
                 global $wp;
 
@@ -26 +24 @@
         }
 
         public function test_adds_query_var_if_public() {
-                $this->set_permalink_structure( '/%postname%' );
-
                 /* @var WP $wp */
                 global $wp;
 
@@ -51 +47 @@
         }
 
         public function test_adds_rewrite_rules() {
-                $this->set_permalink_structure( '/%postname%' );
-
                 /* @var WP_Rewrite $wp_rewrite */
                 global $wp_rewrite;
 

tests/phpunit/tests/user/author.php

@@ -10 +10 @@
         protected static $author_id = 0;
         protected static $post_id   = 0;
 
-        private $permalink_structure;
-
         public static function wpSetUpBeforeClass( WP_UnitTest_Factory $factory ) {
                 self::$author_id = $factory->user->create(
                         array(
@@ -118 +116 @@
 
                 $GLOBALS['authordata'] = $author->data;
 
-                $link = get_the_author_posts_link();
 
-                $url = sprintf( 'http://%1$s/?author=%2$s', WP_TESTS_DOMAIN, $author->ID );
+                tests_set_and_flush_permalinks( '' );
+
+                $link = get_the_author_posts_link();
+                $url  = sprintf( 'http://%1$s/?author=%2$s', WP_TESTS_DOMAIN, $author->ID );
 
                 $this->assertContains( $url, $link );
                 $this->assertContains( 'Posts by Foo', $link );
                 $this->assertContains( '>Foo</a>', $link );
 
                 unset( $GLOBALS['authordata'] );
+                tests_reset_and_flush_permalinks();
         }
 
         /**
@@ -148 +149 @@
 
                 $url = sprintf( 'http://%1$s/author/%2$s/', WP_TESTS_DOMAIN, $author->user_nicename );
 
-                $this->set_permalink_structure( '' );
-
                 $this->assertContains( $url, $link );
                 $this->assertContains( 'Posts by Foo', $link );
                 $this->assertContains( '>Foo</a>', $link );