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