From 4549a9297e81ac18a90004983ff1d08a5f54b0cb Mon Sep 17 00:00:00 2001
From: Konstantin Kovshenin <kovshenin@gmail.com>
Date: Tue, 19 Apr 2022 11:27:12 +0300
Subject: [PATCH] Invalidate: Make sure CACHE_DIR exists before writing flags

---
 include/invalidate.php | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/include/invalidate.php b/include/invalidate.php
index 11dd947..f1f153a 100644
--- a/include/invalidate.php
+++ b/include/invalidate.php
@@ -134,7 +134,14 @@
 
 	$flags = null;
 	$path = CACHE_DIR . '/flags.json.php';
-	$mode = file_exists( $path ) ? 'r+' : 'w+';
+	$exists = file_exists( $path );
+	$mode = $exists ? 'r+' : 'w+';
+
+	// Make sure cache dir exists.
+	if ( ! $exists && ! wp_mkdir_p( CACHE_DIR ) ) {
+		return;
+	}
+
 	$f = fopen( $path, $mode );
 	$length = filesize( $path );