Saturday, February 26, 2011

Kobo and long-unfixed bugs

This article is part of an extended series on Kobo development and investigation

Apparently I have to make this more obvious:

  • Take a backup of your Kobo's SD card before doing anything. If something doesn't work, you can't fix your Kobo without this backup. I will not send you a backup.
  • Any device hacking is risky. If you can't afford to break your device, leave now.

(This post is part of a series on the internals of the Kobo and Kobo Wifi eReaders. The rest of the posts are technically focused; this one was just prompted by increasing frustration with the device.)

I really like the Kobo. It has great hardware, a great price, and some pretty nice software running on it. Unfortunately, it also has some annoying bugs and limitations - many of which wouldn't be too bad,if only there was any sign they'd ever get fixed/resolved. some but not all of which have now been fixed in the 1.9 firmware.

I feel a little bad paying the Kobo out about these issues, because the Kobo folks were really great to deal with and really responsive early on. I've been absolutely blown away by how far beyond narrow-interpretation GPL requirements they've gone with their source releases (including full build scripts and config files) and how quick they were to update their releases when asked about them. Please keep in mind that overall the Kobo is an excellent eReader and the Kobo guys deserve our support for being one of the depressingly few companies who fully accept, understand and act on the obligations that fall on them in exchange for the free use of GPL-licensed software.

Friday, February 25, 2011

Drupal 7, PostgreSQL, unserialize, and bytea_output

I just found out that PHP 5.3's PostgreSQL PDO driver (as used by Drupal) is broken by the Postgresql 8.0 transition from octal to hex encoding for bytea. It passes the raw hex through to the app, including the leading x , causing PHP's unserialize() function to choke.

I'm using Drupal with Apache and PostgreSQL on Windows (sigh) because I'm writing up a step-by-step hand-holding guide for someone who needs to do some testing against our Drupal database. I wouldn't be using that configuration voluntarily ;-)

Drupal doesn't check that bytea_output is set to 'escape' as a workaround or do a sanity test to detect this fault, so the results are ... interesting:

Notice: unserialize(): Error at offset 0 of 27 bytes in variable_initialize() (line 749 of C:\Program Files\Apache Software Foundation\Apache2.2\htdocs\drupal-7.0\includes\

If anybody else lands up whacking their head against this for a while: just

ALTER DATABASE drupal SET bytea_output = 'escape'

to have your sanity restored.

The amount of breakage being seen in drivers really makes me wonder if the the octal to hex transition should've been done with an opt-in from drivers during negotiation or an explicit SET, rather than just making it globally default. But, hey, hindsight.

Friday, February 4, 2011

Handling file uploads with Java EE 6 / JAX-RS / Glassfish / Uploadify

UPDATE: This article is very obsolete. RichFaces 4, among other framworks, now handles multi-file upload out of the box. Use that instead.

Joeri Sykora wrote about using Jersey extensions to JAX-RS to handle file uploads in Java EE 6. His example is extremely handy, but needs some updates to handle Jersey 1.5.

Update: I've now put together a complete and self contained Java EE upload application using Uploadify, which you can grab from See

How to get the context path (context root) in jsf2



For some insane reason, none of the methods that should work would work when invoked via a @RequestScoped object with @Inject @FacesContext - they all merrily returned the empty string. More stupid CDI/JSF brokenness.