Bug 259713 – JSON.parse error in cloudflare check page

• Status: RESOLVED
• Resolution: FIXED
• Component: JavaScriptCore

on websites that use cloudflare for "protection", the "checking security" page doesn't complete

```
[Error] SyntaxError: JSON Parse error: Invalid escape character '
	parse (v1:1:157907)
	gR (v1:1:157907)
	aQnCf (v1:1:149338)
	gV (v1:1:149374)
	gQ (v1:1:137483)
	h4 (v1:1:124536)
	fD (v1:1:121510)
	BBcuN (v1:1:141832)
	(anonymous function) (v1:1:142405)
	(anonymous function) (v1:1:142161)
```

this only happens in Epiphany stable, not nightly

on matrix people said it doesn't happen when the js debugger is on

[Michael Catanzaro]

Please, always provide WebKitGTK version when reporting a bug. You mentioned on Matrix this was with WebKitGTK 2.40.4, which is 260527.381@webkitglib/2.40 (86182cd30e2b8c7ab3414e0c883a333033868a12).

[Michael Catanzaro]

We think this is a bug with the DFG JIT tier because a user reports on Matrix that the problem goes away when using JSC_useDFGJIT=0. There are two DFG fixes in WebKitGTK 2.40.5, from bug #256865 and bug #257285. It makes sense to test that before asking JSC developers to investigate further.

Also, the problem reportedly does not occur in Tech Preview (at least, it certainly doesn't occur for me), so if it's not fixed in 2.40.5 it might be bisectable.

[Radar WebKit Bug Importer]

<rdar://problem/113592447>

[Michael Catanzaro]

Any chance this was indeed fixed by WebKitGTK 2.40.5?

Can you provide an example website where the problem can be reproduced? I want to see if it is bisectable.

it was on many sites including gitlab.com/users/sign_in, but i can't reproduce this any more