Ticket #33999: 33999.diff

src/wp-admin/includes/file.php

@@ -148 +148 @@
                 $dir = get_temp_dir();
         }
 
-        if ( empty( $filename ) || '.' == $filename || '/' == $filename ) {
+        if ( empty( $filename ) || '.' == $filename || DIRECTORY_SEPARATOR == $filename ) {
                 $filename = time();
         }
 

tests/phpunit/tests/file.php

@@ -175 +175 @@
                 );
         }
 
+        /**
+         * @ticket 33999
+         */
+        public function test_wp_tempnam_should_use_timestamp_for_filename_when_filename_is_directory_separator() {
+                $now = time();
+                $file = wp_tempnam( DIRECTORY_SEPARATOR );
+
+                $filename = basename( $file );
+
+                // Only check the first few characters, to account for elapsed second(s).
+                $this->assertSame( substr( $now, 0, 5 ), substr( $filename, 0, 5 ) );
+        }
+
 }