Clean up the INET-vs-CIDR situation. Get rid of the internal is_cidr flag

and rely exclusively on the SQL type system to tell the difference between
the types.  Prevent creation of invalid CIDR values via casting from INET
or set_masklen() --- both of these operations now silently zero any bits
to the right of the netmask.  Remove duplicate CIDR comparison operators,
letting the type rely on the INET operators instead.

2 files changed, 7 insertions, 1 deletions

diff --git a/src/test/regress/expected/opr_sanity.out b/src/test/regress/expected/opr_sanity.out
index aad7a10ed0..f367d0a552 100644
--- a/src/test/regress/expected/opr_sanity.out
+++ b/src/test/regress/expected/opr_sanity.out
@@ -274,6 +274,8 @@ WHERE c.castfunc = p.oid AND
 -- also binary compatible.  This is legal, but usually not intended.
 -- As of 7.4, this finds the casts from text and varchar to bpchar, because
 -- those are binary-compatible while the reverse way goes through rtrim().
+-- As of 8.2, this finds the cast from cidr to inet, because that is a
+-- trivial binary coercion while the other way goes through inet_to_cidr().
 SELECT *
 FROM pg_cast c
 WHERE c.castfunc = 0 AND
@@ -285,7 +287,8 @@ WHERE c.castfunc = 0 AND
 ------------+------------+----------+-------------
          25 |       1042 |        0 | i
        1043 |       1042 |        0 | i
-(2 rows)
+        650 |        869 |        0 | i
+(3 rows)
 
 -- **************** pg_operator ****************
 -- Look for illegal values in pg_operator fields.
diff --git a/src/test/regress/sql/opr_sanity.sql b/src/test/regress/sql/opr_sanity.sql
index ea5bc5b436..0528e3657c 100644
--- a/src/test/regress/sql/opr_sanity.sql
+++ b/src/test/regress/sql/opr_sanity.sql
@@ -223,6 +223,9 @@ WHERE c.castfunc = p.oid AND
 -- As of 7.4, this finds the casts from text and varchar to bpchar, because
 -- those are binary-compatible while the reverse way goes through rtrim().
 
+-- As of 8.2, this finds the cast from cidr to inet, because that is a
+-- trivial binary coercion while the other way goes through inet_to_cidr().
+
 SELECT *
 FROM pg_cast c
 WHERE c.castfunc = 0 AND