Ticket #60855: 60855-FOR-ILLUSTRATION-PURPOSES-ONLY-DO-NOT-MERGE.patch

src/wp-includes/functions.php

@@ -2081 +2081 @@
                 $dir_perms = 0777;
         }
 
-        if ( @mkdir( $target, $dir_perms, true ) ) {
+        /*
+         * FOR ILLUSTRATION PURPOSES ONLY - DO NOT MERGE THIS PATCH
+         */
 
-                /*
-                 * If a umask is set that modifies $dir_perms, we'll have to re-set
-                 * the $dir_perms correctly with chmod()
-                 */
-                if ( ( $dir_perms & ~umask() ) !== $dir_perms ) {
-                        $folder_parts = explode( '/', substr( $target, strlen( $target_parent ) + 1 ) );
-                        for ( $i = 1, $c = count( $folder_parts ); $i <= $c; $i++ ) {
-                                chmod( $target_parent . '/' . implode( '/', array_slice( $folder_parts, 0, $i ) ), $dir_perms );
+        /*
+         * If a umask is set that modifies $dir_perms, we'll have to re-set
+         * the $dir_perms correctly with chmod()
+         */
+        if ( ( $dir_perms & ~umask() ) !== $dir_perms ) {
+                $is_chmod_required = true;
+        } else {
+                $is_chmod_required = false;
+        }
+
+        /*
+         * We cannot use mkdir()'s own built-in recursive functionality
+         * (when the third argument is true) because it returns an error
+         * if the directory already exists.
+         * See https://core.trac.wordpress.org/ticket/60855.
+         */
+
+        $folder_parts = explode( '/', substr( $target, strlen( $target_parent ) + 1 ) );
+        for ( $i = 1, $c = count( $folder_parts ); $i <= $c; $i++ ) {
+                $intermediate_dir = $target_parent . '/' . implode( '/', array_slice( $folder_parts, 0, $i ) );
+                if ( @mkdir( $intermediate_dir ) ) {
+                        /*
+                         * The mkdir() call succeeded - set permissions if necessary and continue.
+                         */
+                        if ( $is_chmod_required ) {
+                                chmod( $intermediate_dir, $dir_perms );
+                        }
+                        continue;
+                } else {
+                        /*
+                         * The mkdir() call failed - try to find out why.
+                         */
+                        if ( file_exists( $intermediate_dir ) ) {
+                                /*
+                                 * It seems that $intermediate_dir already exists.
+                                 * If it's a directory, we can simply proceed to the next iteration.
+                                 * If it's not a directory, then return failure.
+                                 */
+                                if ( is_dir( $intermediate_dir ) ) {
+                                        continue;
+                                } else {
+                                        return false;
+                                }
+                        } else {
+                                /*
+                                 * It seems that $intermediate_dir does not exist.
+                                 * Return failure.
+                                 */
+                                return false;
                         }
                 }
-
-                return true;
         }
 
-        return false;
+        /*
+         * If we get here, mkdir() was able to create all intermediate directories.
+         * Return success.
+         */
+        return true;
 }
 
 /**