From 3ce7f18e92e9687308ed5d9e516eb7e2f0decadb Mon Sep 17 00:00:00 2001 From: Robert Haas Date: Tue, 24 Apr 2012 09:20:53 -0400 Subject: [PATCH] Casts to or from a domain type are ignored; warn and document. Prohibiting this outright would break dumps taken from older versions that contain such casts, which would create far more pain than is justified here. Per report by Jaime Casanova and subsequent discussion. --- doc/src/sgml/ref/create_cast.sgml | 5 +++++ src/backend/commands/functioncmds.c | 11 +++++++++++ src/test/regress/expected/privileges.out | 1 + 3 files changed, 17 insertions(+) diff --git a/doc/src/sgml/ref/create_cast.sgml b/doc/src/sgml/ref/create_cast.sgml index 964cbf4d41..29ea298a46 100644 --- a/doc/src/sgml/ref/create_cast.sgml +++ b/doc/src/sgml/ref/create_cast.sgml @@ -288,6 +288,11 @@ SELECT CAST ( 2 AS numeric ) + 4.0; convert between data types and a second to apply the modifier. + + A cast to or from a domain type currently has no effect. Casting + to or from a domain uses the casts associated with its underlying type. + + diff --git a/src/backend/commands/functioncmds.c b/src/backend/commands/functioncmds.c index 4125b97e89..5f1c19eb37 100644 --- a/src/backend/commands/functioncmds.c +++ b/src/backend/commands/functioncmds.c @@ -1517,6 +1517,17 @@ CreateCast(CreateCastStmt *stmt) aclcheck_error(aclresult, ACL_KIND_TYPE, format_type_be(targettypeid)); + /* Domains are allowed for historical reasons, but we warn */ + if (sourcetyptype == TYPTYPE_DOMAIN) + ereport(WARNING, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("cast will be ignored because the source data type is a domain"))); + + else if (targettyptype == TYPTYPE_DOMAIN) + ereport(WARNING, + (errcode(ERRCODE_WRONG_OBJECT_TYPE), + errmsg("cast will be ignored because the target data type is a domain"))); + /* Detemine the cast method */ if (stmt->func != NULL) castmethod = COERCION_METHOD_FUNCTION; diff --git a/src/test/regress/expected/privileges.out b/src/test/regress/expected/privileges.out index a816cce1b1..dfaf3a7a7e 100644 --- a/src/test/regress/expected/privileges.out +++ b/src/test/regress/expected/privileges.out @@ -571,6 +571,7 @@ CREATE DOMAIN testdomain2b AS testdomain1; CREATE DOMAIN testdomain3b AS int; CREATE FUNCTION castfunc(int) RETURNS testdomain3b AS $$ SELECT $1::testdomain3b $$ LANGUAGE SQL; CREATE CAST (testdomain1 AS testdomain3b) WITH FUNCTION castfunc(int); +WARNING: cast will be ignored because the source data type is a domain CREATE FUNCTION testfunc5b(a testdomain1) RETURNS int LANGUAGE SQL AS $$ SELECT $1 $$; CREATE FUNCTION testfunc6b(b int) RETURNS testdomain1 LANGUAGE SQL AS $$ SELECT $1::testdomain1 $$; CREATE OPERATOR !! (PROCEDURE = testfunc5b, RIGHTARG = testdomain1);