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Date: Fri, 15 Jan 2016 18:17:37 +0900
Message-ID: <CAGa2bXaowb+cuSbbO+a3vmsE0Va6pERwVUxHM3K-54fbFn4DGA@mail.gmail.com>
To: Stanislav Malyshev <smalyshev@gmail.com>
Cc: "internals@lists.php.net" <internals@lists.php.net>
Content-Type: text/plain; charset=UTF-8
Subject: Re: [PHP-DEV] Fixing bug #71038 session_start() returns TRUE on failure
From: yohgaki@ohgaki.net (Yasuo Ohgaki)

Hi Stas,

On Fri, Jan 15, 2016 at 5:22 PM, Stanislav Malyshev <smalyshev@gmail.com> wrote:
>> Read failure is special because old save handler allowed returning false
>> for read and continued as if there is no errors. I cannot fix this without
>> braking buggy save handlers compatibility.
>
> Ah, you mean when read actually worked but handler returns false? If the
> session is set up correctly, then returning true is OK I guess.

There are many codes like

function read($id) {
  return @file_get_contents(FILE_PATH.$id);
}

It returns FALSE for non-existing session data. i.e. The first access to the
server.

To make it work, user should either
 - check file existence and return '' (empty string)
 - cast FALSE to "string" to get '' (empty string). e.g.
(string)@file_get_contents()

So I cannot return FALSE on session_start() read failure w/o breaking
existing codes. PHP 7.0 is strict for return values, so session_start()
returns FALSE on read failure. Even if it is expected behavior for PHP
7.0, there was bug report on this, though.

Regards,

--
Yasuo Ohgaki
yohgaki@ohgaki.net