Segmentation fault on var_dump() of simplehtmldom object

[andrisi]

When loading bigger files using the simplehtmldom library (http://simplehtmldom.sourceforge.net/) and then doing a var_dump on it will cause a Segmentation fault. Just do a "wget -o index.html http://index.hu" and then run the code below.

<?
require('lib/simplehtmldom/simple_html_dom.php');
$dom = file_get_html('index.html');
var_dump($dom);

[Majkl578]

I got this one:

Fatal error: String length exceeded 2^31-2: 2147483647

Not a segfault. HHVM build from master.

[andrisi]

We might be using different versions, I'm using Using "HipHop VM 3.2.0 (dbg)" version. It still seems to be an error. Or you can create an invalid string from code?

[Majkl578]

Can you try 3.3.0 or nightly? I had master in dbg and didn't get a segfault.

[andrisi]

Tried 3.3, same results. Core dumped: Segmentation fault.

[Majkl578]

Interesting. Could you run it under gdb and obtain a backtrace?

$ gdb --args hhvm test.php
...
(gdb) run
<when it crashes>
(gdb) bt

[paulbiss]

This was fixed recently (I think), try building from master after 27ae84e

If that fixes it we should probably make sure this gets picked for 3.3.1

[andrisi]

gdb output for 3.3 is at: https://gist.github.com/andrisi/79c11c0d05c0b979d88d

[paulbiss]

The patch I referenced wasn't in 3.3 (it will be in 3.3.1)

[paulbiss]

Please re-open if you're still seeing crashes in 3.3.1 or master.

[jurosh]

I have error: Fatal error: String length exceeded 2^31-2 on HipHop VM 3.7.0 using on project in Laravel...

[paulbiss]

The fix for this bug involved triggering a fatal error if the maximum size of the output buffer is exceeded.

[andrisi]

Perhaps printing nothing, or just stopping would be a more plesant fix, then throwing a fatal error on a simple var_dump? We shall do some (unreliable) check before every var_dump() to avoid fatal errors? But of course, using var_dump() in a real setting is uncommon.

[jurosh]

Ok, so my app is working now - I had missing storage folders for some caching... but it was really strange what it was doing...