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-rw-r--r--src/backend/catalog/heap.c49
-rw-r--r--src/backend/catalog/index.c4
-rw-r--r--src/backend/commands/tablecmds.c8
-rw-r--r--src/include/catalog/heap.h4
-rw-r--r--src/test/regress/expected/alter_table.out12
-rw-r--r--src/test/regress/sql/alter_table.sql9
6 files changed, 76 insertions, 10 deletions
diff --git a/src/backend/catalog/heap.c b/src/backend/catalog/heap.c
index 567eb7fd6eb..5d25ce9ec88 100644
--- a/src/backend/catalog/heap.c
+++ b/src/backend/catalog/heap.c
@@ -431,6 +431,7 @@ CheckAttributeNamesTypes(TupleDesc tupdesc, char relkind,
CheckAttributeType(NameStr(tupdesc->attrs[i]->attname),
tupdesc->attrs[i]->atttypid,
tupdesc->attrs[i]->attcollation,
+ NIL, /* assume we're creating a new rowtype */
allow_system_table_mods);
}
}
@@ -439,15 +440,25 @@ CheckAttributeNamesTypes(TupleDesc tupdesc, char relkind,
* CheckAttributeType
*
* Verify that the proposed datatype of an attribute is legal.
- * This is needed because there are types (and pseudo-types)
+ * This is needed mainly because there are types (and pseudo-types)
* in the catalogs that we do not support as elements of real tuples.
+ * We also check some other properties required of a table column.
+ *
+ * If the attribute is being proposed for addition to an existing table or
+ * composite type, pass a one-element list of the rowtype OID as
+ * containing_rowtypes. When checking a to-be-created rowtype, it's
+ * sufficient to pass NIL, because there could not be any recursive reference
+ * to a not-yet-existing rowtype.
* --------------------------------
*/
void
-CheckAttributeType(const char *attname, Oid atttypid, Oid attcollation,
+CheckAttributeType(const char *attname,
+ Oid atttypid, Oid attcollation,
+ List *containing_rowtypes,
bool allow_system_table_mods)
{
char att_typtype = get_typtype(atttypid);
+ Oid att_typelem;
if (atttypid == UNKNOWNOID)
{
@@ -485,6 +496,20 @@ CheckAttributeType(const char *attname, Oid atttypid, Oid attcollation,
TupleDesc tupdesc;
int i;
+ /*
+ * Check for self-containment. Eventually we might be able to allow
+ * this (just return without complaint, if so) but it's not clear how
+ * many other places would require anti-recursion defenses before it
+ * would be safe to allow tables to contain their own rowtype.
+ */
+ if (list_member_oid(containing_rowtypes, atttypid))
+ ereport(ERROR,
+ (errcode(ERRCODE_INVALID_TABLE_DEFINITION),
+ errmsg("composite type %s cannot be made a member of itself",
+ format_type_be(atttypid))));
+
+ containing_rowtypes = lcons_oid(atttypid, containing_rowtypes);
+
relation = relation_open(get_typ_typrelid(atttypid), AccessShareLock);
tupdesc = RelationGetDescr(relation);
@@ -495,19 +520,31 @@ CheckAttributeType(const char *attname, Oid atttypid, Oid attcollation,
if (attr->attisdropped)
continue;
- CheckAttributeType(NameStr(attr->attname), attr->atttypid, attr->attcollation,
+ CheckAttributeType(NameStr(attr->attname),
+ attr->atttypid, attr->attcollation,
+ containing_rowtypes,
allow_system_table_mods);
}
relation_close(relation, AccessShareLock);
+
+ containing_rowtypes = list_delete_first(containing_rowtypes);
+ }
+ else if (OidIsValid((att_typelem = get_element_type(atttypid))))
+ {
+ /*
+ * Must recurse into array types, too, in case they are composite.
+ */
+ CheckAttributeType(attname, att_typelem, attcollation,
+ containing_rowtypes,
+ allow_system_table_mods);
}
/*
* This might not be strictly invalid per SQL standard, but it is
- * pretty useless, and it cannot be dumped, so we must disallow
- * it.
+ * pretty useless, and it cannot be dumped, so we must disallow it.
*/
- if (type_is_collatable(atttypid) && !OidIsValid(attcollation))
+ if (!OidIsValid(attcollation) && type_is_collatable(atttypid))
ereport(ERROR,
(errcode(ERRCODE_INVALID_TABLE_DEFINITION),
errmsg("no collation was derived for column \"%s\" with collatable type %s",
diff --git a/src/backend/catalog/index.c b/src/backend/catalog/index.c
index 7a2629ecd19..679255a199b 100644
--- a/src/backend/catalog/index.c
+++ b/src/backend/catalog/index.c
@@ -403,7 +403,9 @@ ConstructTupleDescriptor(Relation heapRelation,
* whether a table column is of a safe type (which is why we
* needn't check for the non-expression case).
*/
- CheckAttributeType(NameStr(to->attname), to->atttypid, to->attcollation, false);
+ CheckAttributeType(NameStr(to->attname),
+ to->atttypid, to->attcollation,
+ NIL, false);
}
/*
diff --git a/src/backend/commands/tablecmds.c b/src/backend/commands/tablecmds.c
index d7573b8ef50..737ab1a7bc8 100644
--- a/src/backend/commands/tablecmds.c
+++ b/src/backend/commands/tablecmds.c
@@ -4221,7 +4221,9 @@ ATExecAddColumn(AlteredTableInfo *tab, Relation rel,
collOid = GetColumnDefCollation(NULL, colDef, typeOid);
/* make sure datatype is legal for a column */
- CheckAttributeType(colDef->colname, typeOid, collOid, false);
+ CheckAttributeType(colDef->colname, typeOid, collOid,
+ list_make1_oid(rel->rd_rel->reltype),
+ false);
/* construct new attribute's pg_attribute entry */
attribute.attrelid = myrelid;
@@ -6536,7 +6538,9 @@ ATPrepAlterColumnType(List **wqueue,
targetcollid = GetColumnDefCollation(NULL, def, targettype);
/* make sure datatype is legal for a column */
- CheckAttributeType(colName, targettype, targetcollid, false);
+ CheckAttributeType(colName, targettype, targetcollid,
+ list_make1_oid(rel->rd_rel->reltype),
+ false);
if (tab->relkind == RELKIND_RELATION)
{
diff --git a/src/include/catalog/heap.h b/src/include/catalog/heap.h
index 5f9a864be5f..463aff0358f 100644
--- a/src/include/catalog/heap.h
+++ b/src/include/catalog/heap.h
@@ -117,7 +117,9 @@ extern Form_pg_attribute SystemAttributeByName(const char *attname,
extern void CheckAttributeNamesTypes(TupleDesc tupdesc, char relkind,
bool allow_system_table_mods);
-extern void CheckAttributeType(const char *attname, Oid atttypid, Oid attcollation,
+extern void CheckAttributeType(const char *attname,
+ Oid atttypid, Oid attcollation,
+ List *containing_rowtypes,
bool allow_system_table_mods);
#endif /* HEAP_H */
diff --git a/src/test/regress/expected/alter_table.out b/src/test/regress/expected/alter_table.out
index d5a59d5d1d4..578f94bc64c 100644
--- a/src/test/regress/expected/alter_table.out
+++ b/src/test/regress/expected/alter_table.out
@@ -1493,6 +1493,18 @@ create table tab1 (a int, b text);
create table tab2 (x int, y tab1);
alter table tab1 alter column b type varchar; -- fails
ERROR: cannot alter table "tab1" because column "tab2"."y" uses its rowtype
+-- disallow recursive containment of row types
+create temp table recur1 (f1 int);
+alter table recur1 add column f2 recur1; -- fails
+ERROR: composite type recur1 cannot be made a member of itself
+alter table recur1 add column f2 recur1[]; -- fails
+ERROR: composite type recur1 cannot be made a member of itself
+create temp table recur2 (f1 int, f2 recur1);
+alter table recur1 add column f2 recur2; -- fails
+ERROR: composite type recur1 cannot be made a member of itself
+alter table recur1 add column f2 int;
+alter table recur1 alter column f2 type recur2; -- fails
+ERROR: composite type recur1 cannot be made a member of itself
--
-- lock levels
--
diff --git a/src/test/regress/sql/alter_table.sql b/src/test/regress/sql/alter_table.sql
index 6531a9f162d..54dbb8eaf9d 100644
--- a/src/test/regress/sql/alter_table.sql
+++ b/src/test/regress/sql/alter_table.sql
@@ -1112,6 +1112,15 @@ create table tab1 (a int, b text);
create table tab2 (x int, y tab1);
alter table tab1 alter column b type varchar; -- fails
+-- disallow recursive containment of row types
+create temp table recur1 (f1 int);
+alter table recur1 add column f2 recur1; -- fails
+alter table recur1 add column f2 recur1[]; -- fails
+create temp table recur2 (f1 int, f2 recur1);
+alter table recur1 add column f2 recur2; -- fails
+alter table recur1 add column f2 int;
+alter table recur1 alter column f2 type recur2; -- fails
+
--
-- lock levels
--
generated by cgit v1.2.3 (git 2.25.1) at 2025-08-15 00:53:49 +0000