[HACKERS] Silent bug in transformIndexConstraint

[Serge Rielau]

In parse_utilcmd.c: transformIndexConstraint() resides the following piece 
of code:

/* * For UNIQUE and PRIMARY KEY, we just have a list of column names. * * 
Make sure referenced keys exist. If we are making a PRIMARY KEY index, * 
also make sure they are NOT NULL, if possible. (Although we could leave * 
it to DefineIndex to mark the columns NOT NULL, it's more efficient to * 
get it right the first time.) */ foreach(lc, constraint->keys) { char *key 
= strVal(lfirst(lc));
The strVal() is wrong since first(lc) returns an IndexElem * and not a 
Value * and we should be doing: char *key = ((IndexElem *) 
lfirst(lc))->name
The existing code only works by luck because Value.val.str happens to match 
the same offset as IndexElem.name.