Fix oversight in ALTER TYPE: typmodin/typmodout must propagate to arrays.

If a base type supports typmods, its array type does too, with the
same interpretation.  Hence changes in pg_type.typmodin/typmodout
must be propagated to the array type.

While here, improve AlterTypeRecurse to not recurse to domains if
there is nothing we'd need to change.

Oversight in fe30e7ebf.  Back-patch to v13 where that came in.

src/backend/commands/typecmds.c

@@ -127,7 +127,8 @@ static char *domainAddConstraint(Oid domainOid, Oid domainNamespace,
 								 const char *domainName, ObjectAddress *constrAddr);
 static Node *replace_domain_constraint_value(ParseState *pstate,
 											 ColumnRef *cref);
-static void AlterTypeRecurse(Oid typeOid, HeapTuple tup, Relation catalog,
+static void AlterTypeRecurse(Oid typeOid, bool isImplicitArray,
+							 HeapTuple tup, Relation catalog,
 							 AlterTypeRecurseParams *atparams);
 
 
@@ -3853,8 +3854,8 @@ AlterType(AlterTypeStmt *stmt)
 				 errmsg("%s is not a base type",
 						format_type_be(typeOid))));
 
-	/* OK, recursively update this type and any domains over it */
-	AlterTypeRecurse(typeOid, tup, catalog, &atparams);
+	/* OK, recursively update this type and any arrays/domains over it */
+	AlterTypeRecurse(typeOid, false, tup, catalog, &atparams);
 
 	/* Clean up */
 	ReleaseSysCache(tup);
@@ -3870,13 +3871,15 @@ AlterType(AlterTypeStmt *stmt)
  * AlterTypeRecurse: one recursion step for AlterType()
  *
  * Apply the changes specified by "atparams" to the type identified by
- * "typeOid", whose existing pg_type tuple is "tup".  Then search for any
- * domains over this type, and recursively apply (most of) the same changes
- * to those domains.
+ * "typeOid", whose existing pg_type tuple is "tup".  If necessary,
+ * recursively update its array type as well.  Then search for any domains
+ * over this type, and recursively apply (most of) the same changes to those
+ * domains.
  *
  * We need this because the system generally assumes that a domain inherits
  * many properties from its base type.  See DefineDomain() above for details
- * of what is inherited.
+ * of what is inherited.  Arrays inherit a smaller number of properties,
+ * but not none.
  *
  * There's a race condition here, in that some other transaction could
  * concurrently add another domain atop this base type; we'd miss updating
@@ -3888,7 +3891,8 @@ AlterType(AlterTypeStmt *stmt)
  * committed.
  */
 static void
-AlterTypeRecurse(Oid typeOid, HeapTuple tup, Relation catalog,
+AlterTypeRecurse(Oid typeOid, bool isImplicitArray,
+				 HeapTuple tup, Relation catalog,
 				 AlterTypeRecurseParams *atparams)
 {
 	Datum		values[Natts_pg_type];
@@ -3949,12 +3953,43 @@ AlterTypeRecurse(Oid typeOid, HeapTuple tup, Relation catalog,
 							 NULL,	/* don't have defaultExpr handy */
 							 NULL,	/* don't have typacl handy */
 							 0, /* we rejected composite types above */
-							 false, /* and we rejected implicit arrays above */
-							 false, /* so it can't be a dependent type */
+							 isImplicitArray,	/* it might be an array */
+							 isImplicitArray,	/* dependent iff it's array */
 							 true);
 
 	InvokeObjectPostAlterHook(TypeRelationId, typeOid, 0);
 
+	/*
+	 * Arrays inherit their base type's typmodin and typmodout, but none of
+	 * the other properties we're concerned with here.  Recurse to the array
+	 * type if needed.
+	 */
+	if (!isImplicitArray &&
+		(atparams->updateTypmodin || atparams->updateTypmodout))
+	{
+		Oid			arrtypoid = ((Form_pg_type) GETSTRUCT(newtup))->typarray;
+
+		if (OidIsValid(arrtypoid))
+		{
+			HeapTuple	arrtup;
+			AlterTypeRecurseParams arrparams;
+
+			arrtup = SearchSysCache1(TYPEOID, ObjectIdGetDatum(arrtypoid));
+			if (!HeapTupleIsValid(arrtup))
+				elog(ERROR, "cache lookup failed for type %u", arrtypoid);
+
+			memset(&arrparams, 0, sizeof(arrparams));
+			arrparams.updateTypmodin = atparams->updateTypmodin;
+			arrparams.updateTypmodout = atparams->updateTypmodout;
+			arrparams.typmodinOid = atparams->typmodinOid;
+			arrparams.typmodoutOid = atparams->typmodoutOid;
+
+			AlterTypeRecurse(arrtypoid, true, arrtup, catalog, &arrparams);
+
+			ReleaseSysCache(arrtup);
+		}
+	}
+
 	/*
 	 * Now we need to recurse to domains.  However, some properties are not
 	 * inherited by domains, so clear the update flags for those.
@@ -3963,6 +3998,12 @@ AlterTypeRecurse(Oid typeOid, HeapTuple tup, Relation catalog,
 	atparams->updateTypmodin = false;	/* domains don't have typmods */
 	atparams->updateTypmodout = false;
 
+	/* Skip the scan if nothing remains to be done */
+	if (!(atparams->updateStorage ||
+		  atparams->updateSend ||
+		  atparams->updateAnalyze))
+		return;
+
 	/* Search pg_type for possible domains over this type */
 	ScanKeyInit(&key[0],
 				Anum_pg_type_typbasetype,
@@ -3983,7 +4024,7 @@ AlterTypeRecurse(Oid typeOid, HeapTuple tup, Relation catalog,
 		if (domainForm->typtype != TYPTYPE_DOMAIN)
 			continue;
 
-		AlterTypeRecurse(domainForm->oid, domainTup, catalog, atparams);
+		AlterTypeRecurse(domainForm->oid, false, domainTup, catalog, atparams);
 	}
 
 	systable_endscan(scan);

src/test/regress/expected/create_type.out

@@ -270,6 +270,14 @@ FROM pg_type WHERE typname = 'myvarchar';
  myvarcharin | myvarcharout | myvarcharrecv | myvarcharsend | varchartypmodin | varchartypmodout | array_typanalyze | x
 (1 row)
 
+SELECT typinput, typoutput, typreceive, typsend, typmodin, typmodout,
+       typanalyze, typstorage
+FROM pg_type WHERE typname = '_myvarchar';
+ typinput | typoutput | typreceive |  typsend   |    typmodin     |    typmodout     |    typanalyze    | typstorage 
+----------+-----------+------------+------------+-----------------+------------------+------------------+------------
+ array_in | array_out | array_recv | array_send | varchartypmodin | varchartypmodout | array_typanalyze | x
+(1 row)
+
 SELECT typinput, typoutput, typreceive, typsend, typmodin, typmodout,
        typanalyze, typstorage
 FROM pg_type WHERE typname = 'myvarchardom';
@@ -278,6 +286,14 @@ FROM pg_type WHERE typname = 'myvarchardom';
  domain_in | myvarcharout | domain_recv | myvarcharsend | -        | -         | array_typanalyze | x
 (1 row)
 
+SELECT typinput, typoutput, typreceive, typsend, typmodin, typmodout,
+       typanalyze, typstorage
+FROM pg_type WHERE typname = '_myvarchardom';
+ typinput | typoutput | typreceive |  typsend   | typmodin | typmodout |    typanalyze    | typstorage 
+----------+-----------+------------+------------+----------+-----------+------------------+------------
+ array_in | array_out | array_recv | array_send | -        | -         | array_typanalyze | x
+(1 row)
+
 -- ensure dependencies are straight
 DROP FUNCTION myvarcharsend(myvarchar);  -- fail
 ERROR:  cannot drop function myvarcharsend(myvarchar) because other objects depend on it

src/test/regress/sql/create_type.sql

@@ -214,10 +214,18 @@ SELECT typinput, typoutput, typreceive, typsend, typmodin, typmodout,
        typanalyze, typstorage
 FROM pg_type WHERE typname = 'myvarchar';
 
+SELECT typinput, typoutput, typreceive, typsend, typmodin, typmodout,
+       typanalyze, typstorage
+FROM pg_type WHERE typname = '_myvarchar';
+
 SELECT typinput, typoutput, typreceive, typsend, typmodin, typmodout,
        typanalyze, typstorage
 FROM pg_type WHERE typname = 'myvarchardom';
 
+SELECT typinput, typoutput, typreceive, typsend, typmodin, typmodout,
+       typanalyze, typstorage
+FROM pg_type WHERE typname = '_myvarchardom';
+
 -- ensure dependencies are straight
 DROP FUNCTION myvarcharsend(myvarchar);  -- fail
 DROP TYPE myvarchar;  -- fail