Invalid JSON in FileCookieJar

[greg0ire]

Q	A
Bug?	yes
New Feature?	no
Version	5.3.1

Actual Behavior

Invalid json is saved in the file used as backend for FileCookieJar. I have had this issue in the past with what might be another version, I remember there were 2 extra brackets at the end of the file. I experienced the issue today again, but I arrived too late to see the invalid contents, which had already been replaced (which kind of makes me think that there might have been many concurrent writes). I know it was invalid because I got: Unable to parse JSON data: JSON_ERROR_SYNTAX - Syntax error, malformed JSON and it came from here.

Expected Behavior

A cookie jar containing valid JSON

Steps to Reproduce

I'm not sure how to reproduce this, I think it might happen with many concurrent writes.

Possible Solutions

Just prevent concurrent writes:

-        if (false === file_put_contents($filename, json_encode($json))) {
+        if (false === file_put_contents($filename, json_encode($json), LOCK_EX)) {

[jbilbo]

This exact same thing happened to me too. Also the extra ] at the end.
@greg0ire did your patch fix it for you?

[greg0ire]

I'm not sure I tried it on a production system, maybe you can try it?

[jbilbo]

I'm monitoring if it happens again (only happened once so far) and will try it if that's the case.

[sagikazarmark]

I think #2335 should fix this issue.

[greg0ire]

It's a backport of #1884 that I wrote a long time ago, so I think the issue is fixed. Let's close this and see if people reopen.