Periodically called synchronous AJAX causes crash by having too many file handles open

[szantaii]

Description:

  A perdiodically called synchronous AJAX call makes Midori crash by
  having too many file handles open.

  It is not easy to achieve this crash, but I'd like to use Midori for a
  display which is on 24/7, and has a webapp running. I tried to be
  detailed on this one, and attached a tar.gz file which helps testing.

Steps to reproduce:

  1. Download the attached tar.gz file and extract it, you'll get a
     folder called 'bugtest'.

     tar -xvzf bugtest.tar.gz

  2. Enter the folder 'bugtest' in a terminal.

     cd bugtest

  3. Start a Python SimpleHTTPServer.

     python -m SimpleHTTPServer

  4. Open another terminal and use 'lsof' to get the number of open
     files of midori.

     while true ; do lsof -c midori | wc -l ; sleep 1 ; done

  5. Open another terminal, and run Midori.

  6. Open the 'test.html' in Midori served by the Python SimpleHTTPServer,
     (usually) located at http://0.0.0.0:8000/test.html

  7. Watch your second terminal to see how the number of open file
     handles grow to a point when it doesn't grow any further.
     (Usually 1207 open file handles is the maxmimum amount.)

  8. Open another tab in Midori, and start typing an URL into the
     address bar.

Actual result:

  Midori crashes with the following message:

    ** (midori4:28918): WARNING **: midori-historycompletion.vala:25:
    Failed to get row unable to open database file

    (midori4:28918): GLib-ERROR **: Creating pipes for GWakeup:
    Too many open files

    Trace/breakpoint trap (core dumped)

Affected Midori versions: 0.4.3, 0.5.8

  Version 0.4.3 was tested on the following systems:

    Raspbian (Linux raspberrypi 3.12.20+ #685 PREEMPT
    Fri May 23 18:59:01 BST 2014 armv6l GNU/Linux)

    Ubuntu 13.10 64 bit (Linux mylaptop 3.11.0-20-generic #35-Ubuntu
    SMP Fri May 2 21:32:49 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux)

  Version 0.5.8 was built from source and was tested on:

    Ubuntu 13.10 64 bit (Linux mylaptop 3.11.0-20-generic #35-Ubuntu
    SMP Fri May 2 21:32:49 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux)