Automatic PDF email report not working when PDF report is linked to deleted site #2155

A few users in the forums are having issues with Emails with PDF reports not sent automatically, when cron is not setup.

http://forum.piwik.org/read.php?2,72692

Piwik tries to trigger the PDF emails automatically in the Task Scheduler.

We should make it easy to enable Debug information, and log it in a file with the current date in the filename, in piwik/tmp/

Then users could send us their log files when having specific problems like this one.

Logging might have to be customized by module to limit noise. For example, enable debug logging only for "TaskShedule" hook, or class.

THis ticket is about

• implementing better log in file feature
• add logging for at least the PDF emails to find the bug
• fix an issue or find out about a possible webhost limitation

another report (there are many like this one...) http://forum.piwik.org/read.php?2,73622

I'm pretty sure this is the bug caused by #2314. Fixing #2314 is fine, but won't solve it for existing users that have reports for deleted sites, so let's fix this issue separately here

(In [4458]) Fixes #2155 by joining PDF and website table