Fix - multsite table up

src/Schema/Builder.php

@@ -263,11 +263,23 @@ public function register_custom_tables_names() {
 	 * @return array<mixed> A list of each creation or update result.
 	 */
 	public function up( $force = false ) {
-		/*
-		 * The value will be `false` if the value has not been set yet or the blog is not installed.
-		 * In either case we should not try to create the tables.
-		 */
-		$is_blog_installed = wp_cache_get( 'is_blog_installed' );
+		if ( doing_action( 'switch_blog' ) ) {
+			/*
+			 * The `switch_blog` action can be called by the `wp_initialize_site` function, before the blog exists.
+			 * Running `is_blog_installed()` in this case will kill the site with a dead db message since the
+			 * `users` table will be found (it's common for all blogs), but the `options` table will not be found for
+			 * the blog.
+			 * If the blog does not exist, the value will not be cached yet and the value will be `false`.
+			 * Else we can just use the value; this will be the case for a normal `switch_blog` action that does not
+			 * fire while creating the site.
+			 *
+			 * When is the next chance to create the tables? Likely in the `activate_blog` action that will be fired
+			 * in the same request following the blog creation or in the next `switch_blog` action.
+			 */
+			$is_blog_installed = wp_cache_get( 'is_blog_installed' );
+		} else {
+			$is_blog_installed = is_blog_installed();
+		}
 
 		if ( ! $is_blog_installed || wp_installing() ) {
 			return [];

tests/wpunit/BuilderTest.php

@@ -365,4 +365,76 @@ public function update() {
 		Register::remove_table( $klutz_table );
 		Register::remove_table( $zorps_table );
 	}
+
+	/**
+	 * @test
+	 */
+	public function should_not_create_tables_during_switch_blog_if_blog_not_installed(): void {
+		// Register the table.
+		$table = $this->get_simple_table();
+		Register::table( $table );
+		$table->drop();
+		// Sanity check.
+		$this->assertFalse( $table->exists() );
+		// Set up as if switching to a blog before it's installed, during its creeation.
+		wp_cache_delete( 'is_blog_installed' );
+		// Remove all other filters to avoid side-effects.
+		remove_all_filters( 'switch_blog' );
+
+		$builder = Schema::builder();
+
+		add_action( 'switch_blog', [ $builder, 'update_blog_tables' ] );
+
+		do_action( 'switch_blog', 66 );
+
+		$this->assertFalse( $table->exists() );
+	}
+
+	/**
+	 * @test
+	 */
+	public function should_create_tables_during_switch_blog_if_blog_installed(): void {
+		// Register the table.
+		$table = $this->get_simple_table();
+		Register::table( $table );
+		$table->drop();
+		// Sanity check.
+		$this->assertFalse( $table->exists() );
+		// Set up as if switching to a blog after it's installed.
+		wp_cache_set( 'is_blog_installed', true );
+		// Remove all other filters to avoid side-effects.
+		remove_all_filters( 'switch_blog' );
+
+		$builder = Schema::builder();
+
+		add_action( 'switch_blog', [ $builder, 'update_blog_tables' ] );
+
+		do_action( 'switch_blog', 66 );
+
+		$this->assertTrue( $table->exists() );
+	}
+
+	/**
+	 * @test
+	 */
+	public function should_create_tables_during_activate_blog(): void {
+		// Register the table.
+		$table = $this->get_simple_table();
+		Register::table( $table );
+		$table->drop();
+		// Sanity check.
+		$this->assertFalse( $table->exists() );
+		// Set up as if switching to a blog after it's installed.
+		wp_cache_set( 'is_blog_installed', true );
+		// Remove all other filters to avoid side-effects.
+		remove_all_filters( 'activate_blog' );
+
+		$builder = Schema::builder();
+
+		add_action( 'activate_blog', [ $builder, 'update_blog_tables' ] );
+
+		do_action( 'activate_blog', 66 );
+
+		$this->assertTrue( $table->exists() );
+	}
 }