--
-- Regular expression tests
--
-- Don't want to have to double backslashes in regexes
set standard_conforming_strings = on;
-- Test simple quantified backrefs
select 'bbbbb' ~ '^([bc])\1*$' as t;
 t 
---
 t
(1 row)

select 'ccc' ~ '^([bc])\1*$' as t;
 t 
---
 t
(1 row)

select 'xxx' ~ '^([bc])\1*$' as f;
 f 
---
 f
(1 row)

select 'bbc' ~ '^([bc])\1*$' as f;
 f 
---
 f
(1 row)

select 'b' ~ '^([bc])\1*$' as t;
 t 
---
 t
(1 row)

-- Test quantified backref within a larger expression
select 'abc abc abc' ~ '^(\w+)( \1)+$' as t;
 t 
---
 t
(1 row)

select 'abc abd abc' ~ '^(\w+)( \1)+$' as f;
 f 
---
 f
(1 row)

select 'abc abc abd' ~ '^(\w+)( \1)+$' as f;
 f 
---
 f
(1 row)

select 'abc abc abc' ~ '^(.+)( \1)+$' as t;
 t 
---
 t
(1 row)

select 'abc abd abc' ~ '^(.+)( \1)+$' as f;
 f 
---
 f
(1 row)

select 'abc abc abd' ~ '^(.+)( \1)+$' as f;
 f 
---
 f
(1 row)

-- Test some cases that crashed in 9.2beta1 due to pmatch[] array overrun
select substring('asd TO foo' from ' TO (([a-z0-9._]+|"([^"]+|"")+")+)');
 substring 
-----------
 foo
(1 row)

select substring('a' from '((a))+');
 substring 
-----------
 a
(1 row)

select substring('a' from '((a)+)');
 substring 
-----------
 a
(1 row)

-- Test conversion of regex patterns to indexable conditions
explain (costs off) select * from pg_proc where proname ~ 'abc';
            QUERY PLAN             
-----------------------------------
 Seq Scan on pg_proc
   Filter: (proname ~ 'abc'::text)
(2 rows)

explain (costs off) select * from pg_proc where proname ~ '^abc';
                              QUERY PLAN                              
----------------------------------------------------------------------
 Index Scan using pg_proc_proname_args_nsp_index on pg_proc
   Index Cond: ((proname >= 'abc'::name) AND (proname < 'abd'::name))
   Filter: (proname ~ '^abc'::text)
(3 rows)

explain (costs off) select * from pg_proc where proname ~ '^abc$';
                         QUERY PLAN                         
------------------------------------------------------------
 Index Scan using pg_proc_proname_args_nsp_index on pg_proc
   Index Cond: (proname = 'abc'::name)
   Filter: (proname ~ '^abc$'::text)
(3 rows)

explain (costs off) select * from pg_proc where proname ~ '^abcd*e';
                              QUERY PLAN                              
----------------------------------------------------------------------
 Index Scan using pg_proc_proname_args_nsp_index on pg_proc
   Index Cond: ((proname >= 'abc'::name) AND (proname < 'abd'::name))
   Filter: (proname ~ '^abcd*e'::text)
(3 rows)

explain (costs off) select * from pg_proc where proname ~ '^abc+d';
                              QUERY PLAN                              
----------------------------------------------------------------------
 Index Scan using pg_proc_proname_args_nsp_index on pg_proc
   Index Cond: ((proname >= 'abc'::name) AND (proname < 'abd'::name))
   Filter: (proname ~ '^abc+d'::text)
(3 rows)

explain (costs off) select * from pg_proc where proname ~ '^(abc)(def)';
                                 QUERY PLAN                                 
----------------------------------------------------------------------------
 Index Scan using pg_proc_proname_args_nsp_index on pg_proc
   Index Cond: ((proname >= 'abcdef'::name) AND (proname < 'abcdeg'::name))
   Filter: (proname ~ '^(abc)(def)'::text)
(3 rows)

explain (costs off) select * from pg_proc where proname ~ '^(abc)$';
                         QUERY PLAN                         
------------------------------------------------------------
 Index Scan using pg_proc_proname_args_nsp_index on pg_proc
   Index Cond: (proname = 'abc'::name)
   Filter: (proname ~ '^(abc)$'::text)
(3 rows)

explain (costs off) select * from pg_proc where proname ~ '^(abc)?d';
               QUERY PLAN               
----------------------------------------
 Seq Scan on pg_proc
   Filter: (proname ~ '^(abc)?d'::text)
(2 rows)

-- Test for infinite loop in pullback() (CVE-2007-4772)
select 'a' ~ '($|^)*';
 ?column? 
----------
 t
(1 row)

-- Test for infinite loop in fixempties() (Tcl bugs 3604074, 3606683)
select 'a' ~ '((((((a)*)*)*)*)*)*';
 ?column? 
----------
 t
(1 row)

select 'a' ~ '((((((a+|)+|)+|)+|)+|)+|)';
 ?column? 
----------
 t
(1 row)

-- Test backref in combination with non-greedy quantifier
-- https://core.tcl.tk/tcl/tktview/6585b21ca8fa6f3678d442b97241fdd43dba2ec0
select 'Programmer' ~ '(\w).*?\1' as t;
 t 
---
 t
(1 row)

select regexp_matches('Programmer', '(\w)(.*?\1)', 'g');
 regexp_matches 
----------------
 {r,ogr}
 {m,m}
(2 rows)

-- Test for proper matching of non-greedy iteration (bug #11478)
select regexp_matches('foo/bar/baz',
                      '^([^/]+?)(?:/([^/]+?))(?:/([^/]+?))?$', '');
 regexp_matches 
----------------
 {foo,bar,baz}
(1 row)

-- Test for infinite loop in cfindloop with zero-length possible match
-- but no actual match (can only happen in the presence of backrefs)
select 'a' ~ '$()|^\1';
 ?column? 
----------
 f
(1 row)

select 'a' ~ '.. ()|\1';
 ?column? 
----------
 f
(1 row)

select 'a' ~ '()*\1';
 ?column? 
----------
 t
(1 row)

select 'a' ~ '()+\1';
 ?column? 
----------
 t
(1 row)