Submitted by: @pavel-zotov

This query works fine:

with
x as(
select 1 i from rdb$database
)
,y as(
select i from x
)
select * from y as z
;

But this fails:

with
x as(
select 1 i from rdb$database
)
,y as(
select i from x
)
select * from y as x ------------------ NOTE: "as X", i.e. alias for final CTE part ( "y" ) matches to 1st CTE ( "x" )
;

Statement failed, SQLSTATE = 42000
Dynamic SQL Error
-SQL error code = -104
-CTE 'X' has cyclic dependencies

Regression affected only 3.0+.
All builds of 2.5 work Ok (i've checked 2.5.0 ... 2.5.6 and current build of 2.5.8).

Commits: 9e079af b9c1f9f