Fixing bug #71038 session_start() returns TRUE on failure

Hi Stas,

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