SQL function "substr" must be called using substr(string,start,length), with start >= 1. But, what happens if start = 0 ?

Before :

$ sqlite3
SQLite version 3.3.6
Enter ".help" for instructions
sqlite> select substr('ABCD',1,2);
AB
sqlite> select substr('ABCD',0,2);
AB
sqlite> select substr('ABCD',0,1);
A
sqlite>

Now :

$ sqlite3
SQLite version 3.6.12
Enter ".help" for instructions
Enter SQL statements terminated with a ";"
sqlite> select substr('ABCD',1,2);
AB
sqlite> select substr('ABCD',0,2);
A
sqlite> select substr('ABCD',0,1);

sqlite>

New behaviour seems more complying with the standard but break repoview.

Once problem understood, fix is really trivial.

See : Bug #498752

Well, MrIcon, you have work pending ;)