From b5a66e7353ba65c11c5fc6a79b72213bde8dbe44 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Thu, 18 Feb 2021 22:38:55 -0500
Subject: Fix another ancient bug in parsing of BRE-mode regular expressions.

While poking at the regex code, I happened to notice that the bug
squashed in commit afcc8772e had a sibling: next() failed to return
a specific value associated with the '}' token for a "\{m,n\}"
quantifier when parsing in basic RE mode.  Again, this could result
in treating the quantifier as non-greedy, which it never should be in
basic mode.  For that to happen, the last character before "\}" that
sets "nextvalue" would have to set it to zero, or it'd have to have
accidentally been zero from the start.  The failure can be provoked
repeatably with, for example, a bound ending in digit "0".

Like the previous patch, back-patch all the way.
---
 src/test/modules/test_regex/sql/test_regex.sql | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

(limited to 'src/test/modules/test_regex/sql/test_regex.sql')

diff --git a/src/test/modules/test_regex/sql/test_regex.sql b/src/test/modules/test_regex/sql/test_regex.sql
index ae7d6b43e4a..31e947ee9c6 100644
--- a/src/test/modules/test_regex/sql/test_regex.sql
+++ b/src/test/modules/test_regex/sql/test_regex.sql
@@ -214,8 +214,9 @@ select * from test_regex('a?*', '', '-');
 select * from test_regex('a+*', '', '-');
 -- expectError	7.15 -		a*+	BADRPT
 select * from test_regex('a*+', '', '-');
--- test for ancient brenext() bug; not currently in Tcl
+-- tests for ancient brenext() bugs; not currently in Tcl
 select * from test_regex('.*b', 'aaabbb', 'b');
+select * from test_regex('.\{1,10\}', 'abcdef', 'bQ');
 
 -- doing 8 "braces"
 
-- 
cgit v1.2.3

