Bug 4176 - bizarre broken behaviour

[kaberett]

Here is my pull request.

Here is the Bugzilla entry, plus the diff of the draft patch I am building on.

The idea is that we want to add a "User:" line to every support notification e-mail, indicating who was responsible for the activity prompting the notification.

fu pointed out that I need to:

1. remove the quotation marks around $show_name at line 1068
   
2. account for the possibility of $posterid==0 at line 1095

My code as currently in pull request 427 behaves as expected, and as desired except for the issue outlined in point 2.

Removing the quotation marks from line 1068 produces the behaviour that the name of the user who submitted the request is quoted in all subsequent notification e-mails.

• this persists if quotation marks are added back in.
  
• this persists if everything after username => is deleted and rewritten.
  
• this behaviour does not persist if line 1095 is replaced with mapping to a static text string, e.g. username => "badgerbadger", and the change is then committed, but does persist if it is instead mapped to e.g. $posterid.
  
• this behaviour does not persist if the entirety of any line which has ever contained $show_name (without quotation marks) is deleted or commented out.
  
• supportlog in the database is recording the correct information; it's just not making it to e-mail, somehow.

Ideas, please? I am WAY out of my depth here.