From 29667c8536fc99472d22ac617dd965bf5c4f1c5f Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Wed, 24 Feb 2010 18:02:30 +0000
Subject: [PATCH] Allow zero-dimensional (ie, empty) arrays in contrib/ltree
operations.
The main motivation for changing this is bug #4921, in which it's pointed out
that it's no longer safe to apply ltree operations to the result of
ARRAY(SELECT ...) if the sub-select might return no rows. Before 8.3,
the ARRAY() construct would return NULL, which might or might not be helpful
but at least it wouldn't result in an error. Now it returns an empty array
which results in a failure for no good reason, since the ltree operations
are all perfectly capable of dealing with zero-element arrays.
As far as I can find, these ltree functions are the only places where zero
array dimensionality is rejected unnecessarily.
Back-patch to 8.3 to prevent behavioral regression of queries that worked
in older releases.
---
contrib/ltree/_ltree_gist.c | 6 +++---
contrib/ltree/_ltree_op.c | 8 ++++----
contrib/ltree/lquery_op.c | 4 ++--
contrib/ltree/ltree_gist.c | 4 ++--
4 files changed, 11 insertions(+), 11 deletions(-)
diff --git a/contrib/ltree/_ltree_gist.c b/contrib/ltree/_ltree_gist.c
index 15c4cc022d..933e85f17f 100644
--- a/contrib/ltree/_ltree_gist.c
+++ b/contrib/ltree/_ltree_gist.c
@@ -1,5 +1,5 @@
/*
- * $PostgreSQL: pgsql/contrib/ltree/_ltree_gist.c,v 1.26 2009/06/11 14:48:51 momjian Exp $
+ * $PostgreSQL: pgsql/contrib/ltree/_ltree_gist.c,v 1.26.2.1 2010/02/24 18:02:30 tgl Exp $
*
*
* GiST support for ltree[]
@@ -88,7 +88,7 @@ _ltree_compress(PG_FUNCTION_ARGS)
int num = ArrayGetNItems(ARR_NDIM(val), ARR_DIMS(val));
ltree *item = (ltree *) ARR_DATA_PTR(val);
- if (ARR_NDIM(val) != 1)
+ if (ARR_NDIM(val) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
@@ -534,7 +534,7 @@ _arrq_cons(ltree_gist *key, ArrayType *_query)
lquery *query = (lquery *) ARR_DATA_PTR(_query);
int num = ArrayGetNItems(ARR_NDIM(_query), ARR_DIMS(_query));
- if (ARR_NDIM(_query) != 1)
+ if (ARR_NDIM(_query) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
diff --git a/contrib/ltree/_ltree_op.c b/contrib/ltree/_ltree_op.c
index f9e90e978d..ca8032eb7e 100644
--- a/contrib/ltree/_ltree_op.c
+++ b/contrib/ltree/_ltree_op.c
@@ -1,5 +1,5 @@
/*
- * $PostgreSQL: pgsql/contrib/ltree/_ltree_op.c,v 1.13 2009/06/11 14:48:51 momjian Exp $
+ * $PostgreSQL: pgsql/contrib/ltree/_ltree_op.c,v 1.13.2.1 2010/02/24 18:02:30 tgl Exp $
*
*
* op function for ltree[]
@@ -48,7 +48,7 @@ array_iterator(ArrayType *la, PGCALL2 callback, void *param, ltree **found)
int num = ArrayGetNItems(ARR_NDIM(la), ARR_DIMS(la));
ltree *item = (ltree *) ARR_DATA_PTR(la);
- if (ARR_NDIM(la) != 1)
+ if (ARR_NDIM(la) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
@@ -148,7 +148,7 @@ _lt_q_regex(PG_FUNCTION_ARGS)
bool res = false;
int num = ArrayGetNItems(ARR_NDIM(_query), ARR_DIMS(_query));
- if (ARR_NDIM(_query) != 1)
+ if (ARR_NDIM(_query) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
@@ -306,7 +306,7 @@ _lca(PG_FUNCTION_ARGS)
ltree **a,
*res;
- if (ARR_NDIM(la) != 1)
+ if (ARR_NDIM(la) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
diff --git a/contrib/ltree/lquery_op.c b/contrib/ltree/lquery_op.c
index df4f0794f2..f22a508a41 100644
--- a/contrib/ltree/lquery_op.c
+++ b/contrib/ltree/lquery_op.c
@@ -1,7 +1,7 @@
/*
* op function for ltree and lquery
* Teodor Sigaev <teodor@stack.net>
- * $PostgreSQL: pgsql/contrib/ltree/lquery_op.c,v 1.14 2009/06/11 14:48:51 momjian Exp $
+ * $PostgreSQL: pgsql/contrib/ltree/lquery_op.c,v 1.14.2.1 2010/02/24 18:02:30 tgl Exp $
*/
#include "postgres.h"
@@ -344,7 +344,7 @@ lt_q_regex(PG_FUNCTION_ARGS)
bool res = false;
int num = ArrayGetNItems(ARR_NDIM(_query), ARR_DIMS(_query));
- if (ARR_NDIM(_query) != 1)
+ if (ARR_NDIM(_query) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));
diff --git a/contrib/ltree/ltree_gist.c b/contrib/ltree/ltree_gist.c
index d48ca8e1d4..18516831d1 100644
--- a/contrib/ltree/ltree_gist.c
+++ b/contrib/ltree/ltree_gist.c
@@ -1,7 +1,7 @@
/*
* GiST support for ltree
* Teodor Sigaev <teodor@stack.net>
- * $PostgreSQL: pgsql/contrib/ltree/ltree_gist.c,v 1.25 2009/06/11 14:48:51 momjian Exp $
+ * $PostgreSQL: pgsql/contrib/ltree/ltree_gist.c,v 1.25.2.1 2010/02/24 18:02:30 tgl Exp $
*/
#include "postgres.h"
@@ -602,7 +602,7 @@ arrq_cons(ltree_gist *key, ArrayType *_query)
lquery *query = (lquery *) ARR_DATA_PTR(_query);
int num = ArrayGetNItems(ARR_NDIM(_query), ARR_DIMS(_query));
- if (ARR_NDIM(_query) != 1)
+ if (ARR_NDIM(_query) > 1)
ereport(ERROR,
(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
errmsg("array must be one-dimensional")));