Bug in ILIKE?

Good:

regression=# select 'T' ilike 't';?column? 
----------t
(1 row)

Not so good:

regression=# select 'T' ilike E'\\t';?column? 
----------f
(1 row)

ISTM backslash is only supposed to turn off the pattern-language
specialness of characters, not render them case sensitive.  The reason
this happens is that the backslash case in MatchText() checks for exact
equality.  I think it should be checking for TCHAR() equality, same as
when it is just checking two ordinary characters.  Comments?  Is this a
backpatchable bug fix, or should we only change the behavior for 8.4 and
beyond?
        regards, tom lane