My Deluge commands automatically changed ...

My Deluge commands automatically changed ...

I was editing a code section (in free flow mode) when I noticed several Deluge commands of the form ...
  1.         thisEnvelopesColor = ifnull(thisOrderDetails1Record.Envelopes_Color,"");
I did not code this command ... I believe I used ...
  1.         thisEnvelopesColor = if(thisOrderDetails1Record.Envelopes_Color == null,"",thisOrderDetails1Record.Envelopes_Color);
a) when did this change take effect ? ... I do not see any notice of this change in any of the documentation.

b) what is ifnull ? ... I searched the Help documentation ... there is no reference to this command ... where can I get complete details of the syntax and workings of this command ?


Please note that ... due to uncertainty about these unexplained changes ... I am now forced to cease all development of this client's Application ... which will mean that his plans for going live with his Application in the next week are now in jeopardy.

Gaev