Re: Possible bug: SQL function parameter in window frame definition

>>>>> "Tom" == Tom Lane <tgl@sss.pgh.pa.us> writes:

 Tom> However, we need to fix this in all active branches, and I
 Tom> definitely agree with minimizing the amount of change to back
 Tom> branches. The fact that the minimal change breaks (or exposes an
 Tom> oversight in) assign_collations_walker makes it very plausible
 Tom> that it will also break somebody's third-party code. If we push
 Tom> the API change further we increase the risk of breaking stuff.
 Tom> That seems OK in HEAD but not in back branches.

We could minimize the chance of breakage in a back-patched fix by having
query_tree_walker/mutator iterate the windowClause list itself and
invoke the walker only on offset expressions; is it worth it?

Walkers that follow the recommended code structure should be unaffected;
it only shows up in the collations walker because that treats
expressions as the "default" case and tries to explicitly handle all
non-expression nodes.

-- 
Andrew (irc:RhodiumToad)