From 45e02e3232ac7cc5ffe36f7986159b5e0b1f6fdc Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Sat, 23 Nov 2013 20:03:56 -0500
Subject: [PATCH] Fix array slicing of int2vector and oidvector values.
The previous coding labeled expressions such as pg_index.indkey[1:3] as
being of int2vector type; which is not right because the subscript bounds
of such a result don't, in general, satisfy the restrictions of int2vector.
To fix, implicitly promote the result of slicing int2vector to int2[],
or oidvector to oid[]. This is similar to what we've done with domains
over arrays, which is a good analogy because these types are very much
like restricted domains of the corresponding regular-array types.
A side-effect is that we now also forbid array-element updates on such
columns, eg while "update pg_index set indkey[4] = 42" would have worked
before if you were superuser (and corrupted your catalogs irretrievably,
no doubt) it's now disallowed. This seems like a good thing since, again,
some choices of subscripting would've led to results not satisfying the
restrictions of int2vector. The case of an array-slice update was
rejected before, though with a different error message than you get now.
We could make these cases work in future if we added a cast from int2[]
to int2vector (with a cast function checking the subscript restrictions)
but it seems unlikely that there's any value in that.
Per report from Ronan Dunklau. Back-patch to all supported branches
because of the crash risks involved.
---
src/backend/parser/parse_node.c | 13 +++++++++++++
src/backend/parser/parse_target.c | 8 +++++---
src/include/catalog/pg_type.h | 2 ++
3 files changed, 20 insertions(+), 3 deletions(-)
diff --git a/src/backend/parser/parse_node.c b/src/backend/parser/parse_node.c
index 6ffbd767275..e0ea43a8104 100644
--- a/src/backend/parser/parse_node.c
+++ b/src/backend/parser/parse_node.c
@@ -226,6 +226,18 @@ transformArrayType(Oid *arrayType, int32 *arrayTypmod)
*/
*arrayType = getBaseTypeAndTypmod(*arrayType, arrayTypmod);
+ /*
+ * We treat int2vector and oidvector as though they were domains over
+ * int2[] and oid[]. This is needed because array slicing could create an
+ * array that doesn't satisfy the dimensionality constraints of the
+ * xxxvector type; so we want the result of a slice operation to be
+ * considered to be of the more general type.
+ */
+ if (*arrayType == INT2VECTOROID)
+ *arrayType = INT2ARRAYOID;
+ else if (*arrayType == OIDVECTOROID)
+ *arrayType = OIDARRAYOID;
+
/* Get the type tuple for the array */
type_tuple_array = SearchSysCache1(TYPEOID, ObjectIdGetDatum(*arrayType));
if (!HeapTupleIsValid(type_tuple_array))
@@ -263,6 +275,7 @@ transformArrayType(Oid *arrayType, int32 *arrayTypmod)
* For both cases, if the source array is of a domain-over-array type,
* the result is of the base array type or its element type; essentially,
* we must fold a domain to its base type before applying subscripting.
+ * (Note that int2vector and oidvector are treated as domains here.)
*
* pstate Parse state
* arrayBase Already-transformed expression for the array as a whole
diff --git a/src/backend/parser/parse_target.c b/src/backend/parser/parse_target.c
index 9c6c202c8e6..d56e00ffde6 100644
--- a/src/backend/parser/parse_target.c
+++ b/src/backend/parser/parse_target.c
@@ -839,18 +839,20 @@ transformAssignmentSubscripts(ParseState *pstate,
/* If target was a domain over array, need to coerce up to the domain */
if (arrayType != targetTypeId)
{
+ Oid resulttype = exprType(result);
+
result = coerce_to_target_type(pstate,
- result, exprType(result),
+ result, resulttype,
targetTypeId, targetTypMod,
COERCION_ASSIGNMENT,
COERCE_IMPLICIT_CAST,
-1);
- /* probably shouldn't fail, but check */
+ /* can fail if we had int2vector/oidvector, but not for true domains */
if (result == NULL)
ereport(ERROR,
(errcode(ERRCODE_CANNOT_COERCE),
errmsg("cannot cast type %s to %s",
- format_type_be(exprType(result)),
+ format_type_be(resulttype),
format_type_be(targetTypeId)),
parser_errposition(pstate, location)));
}
diff --git a/src/include/catalog/pg_type.h b/src/include/catalog/pg_type.h
index 20813125ab2..a2be2c404b1 100644
--- a/src/include/catalog/pg_type.h
+++ b/src/include/catalog/pg_type.h
@@ -446,6 +446,7 @@ DATA(insert OID = 1001 ( _bytea PGNSP PGUID -1 f b A f t \054 0 17 0 array_in
DATA(insert OID = 1002 ( _char PGNSP PGUID -1 f b A f t \054 0 18 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
DATA(insert OID = 1003 ( _name PGNSP PGUID -1 f b A f t \054 0 19 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
DATA(insert OID = 1005 ( _int2 PGNSP PGUID -1 f b A f t \054 0 21 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
+#define INT2ARRAYOID 1005
DATA(insert OID = 1006 ( _int2vector PGNSP PGUID -1 f b A f t \054 0 22 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
DATA(insert OID = 1007 ( _int4 PGNSP PGUID -1 f b A f t \054 0 23 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
#define INT4ARRAYOID 1007
@@ -453,6 +454,7 @@ DATA(insert OID = 1008 ( _regproc PGNSP PGUID -1 f b A f t \054 0 24 0 array_i
DATA(insert OID = 1009 ( _text PGNSP PGUID -1 f b A f t \054 0 25 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 100 _null_ _null_ _null_ ));
#define TEXTARRAYOID 1009
DATA(insert OID = 1028 ( _oid PGNSP PGUID -1 f b A f t \054 0 26 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
+#define OIDARRAYOID 1028
DATA(insert OID = 1010 ( _tid PGNSP PGUID -1 f b A f t \054 0 27 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
DATA(insert OID = 1011 ( _xid PGNSP PGUID -1 f b A f t \054 0 28 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
DATA(insert OID = 1012 ( _cid PGNSP PGUID -1 f b A f t \054 0 29 0 array_in array_out array_recv array_send - - array_typanalyze i x f 0 -1 0 0 _null_ _null_ _null_ ));
--
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