[BC Break?] "Failed to start the session" error

[kbond]

After upgrading to 2.5.7 I started seeing this error very frequently. It looks like it has to do with #12341 and am only seeing it with PHP 5.3 (5.3.15 specifically). I don't appear to have the issue on PHP 5.5. When I revert to 2.5.6 everything worked as expected.

I am using the PdoSessionHandler.

Here is an excerpt from my logs:

[2014-11-23 11:01:07] security.DEBUG: Remember-me cookie detected. [] []
[2014-11-23 11:01:07] security.INFO: Remember-me cookie accepted. [] []
[2014-11-23 11:01:07] security.DEBUG: SecurityContext populated with remember-me token. [] []
[2014-11-23 11:01:07] security.DEBUG: Write SecurityContext in the session [] []
[2014-11-23 11:01:07] request.CRITICAL: Uncaught PHP Exception RuntimeException: "Failed to start the session: already started by PHP ($_SESSION is set)." at /.../vendor/symfony/symfony/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php line 139 {"exception":"[object] (RuntimeException: Failed to start the session: already started by PHP ($_SESSION is set). at /.../vendor/symfony/symfony/src/Symfony/Component/HttpFoundation/Session/Storage/NativeSessionStorage.php:139)"} []
[2014-11-23 11:01:07] security.DEBUG: Write SecurityContext in the session [] []

(Ref: #12325)

[mcrio]

After upgrading to 2.5.7 I am getting the same issue when using StreamedResponse, PHP 5.3.10.
2.5.6 works fine.

[kbond]

I am not using StreamedResponse - looks like @nikolajosipovic's issue has been reported here: #12423. I am unsure if this issue is related.

[kbond]

Few more notes about this issue:

I am using Symfony's HttpCache, I have a cached full-page layout with an esi fragment that is not cached and accessing the session. I think the exception is being raised during rendering the fragment.

[weaverryan]

@kbond not sure if this is feasible to test, but does manually reverting only #12326 fix the issue? It's the only thing I see on the changelog that looks related - it would at least help confirm things (though the specifics are over my head).

[kbond]

Good idea :). Reverting #12326 didn't fix the issue but reverting #12341 did (commit b7bfef0)

[Tobion]

I'll provide a fix on the weekend.

[AITG]

Just to add another 'me too' here. Just updated from 2.3.5 to 2.3.22 and I get the "RuntimeException: Failed to start the session: already started by PHP ($_SESSION is set)." error.

The exception is raised from here:

cache/dev/classes.php

NativeSessionStorage->start()
...
if (version_compare(phpversion(),'5.4.0','<') && isset($_SESSION) && session_id()) {
throw new \RuntimeException('Failed to start the session: already started by PHP ($_SESSION is set).');
}

That line has changed in 2.3.22,

if (PHP_VERSION_ID < 50400 && isset($_SESSION) && session_id()) {
throw new \RuntimeException('Failed to start the session: already started by PHP ($_SESSION is set).');
}
Downgrading to 2.3.21 fixes it.

God knows the reason for changing what appears to be a perfectly fine block of code though.

[crashbtz]

we had the same problem with php 5.3.27 and that was caused by the "render_esi" command so we removed it temporarily

[Seldaek]

@Tobion I know how it is with weekend projects, but any news on this by any chance? Otherwise could we revert b7bfef0 @fabpot as this is a regression?

[kbond]

Is this related to #12833?

[Tobion]

See #12961 for a fix

[Seldaek]

Just confirming that the fix works for me thanks @Tobion