From f0395d50e9486e1a5691fe4bfab92d4800460c83 Mon Sep 17 00:00:00 2001
From: Tom Lane <tgl@sss.pgh.pa.us>
Date: Mon, 6 Nov 2006 18:21:31 +0000
Subject: [PATCH] Repair bug #2694 concerning an ARRAY[] construct whose inputs
are empty sub-arrays. Per discussion, if all inputs are empty arrays then
result must be an empty array too, whereas a mix of empty and nonempty arrays
should (and already did) draw an error. In the back branches, the construct
was strict: any NULL input immediately yielded a NULL output; so I left that
behavior alone. HEAD was simply ignoring NULL sub-arrays, which doesn't seem
very sensible. For lack of a better idea it now treats NULL sub-arrays the
same as empty ones.
---
src/backend/executor/execQual.c | 39 ++++++++++++++++++++++++++++-----
1 file changed, 34 insertions(+), 5 deletions(-)
diff --git a/src/backend/executor/execQual.c b/src/backend/executor/execQual.c
index 943ae62d3d4..6559947bf1e 100644
--- a/src/backend/executor/execQual.c
+++ b/src/backend/executor/execQual.c
@@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.196 2006/10/06 17:13:59 petere Exp $
+ * $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.197 2006/11/06 18:21:31 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@@ -2280,6 +2280,7 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
int *elem_lbs = NULL;
bool firstone = true;
bool havenulls = false;
+ bool haveempty = false;
char **subdata;
bits8 **subbitmaps;
int *subbytes;
@@ -2302,11 +2303,15 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
bool eisnull;
Datum arraydatum;
ArrayType *array;
+ int this_ndims;
arraydatum = ExecEvalExpr(e, econtext, &eisnull, NULL);
- /* ignore null subarrays */
+ /* temporarily ignore null subarrays */
if (eisnull)
+ {
+ haveempty = true;
continue;
+ }
array = DatumGetArrayTypeP(arraydatum);
@@ -2320,10 +2325,18 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
format_type_be(ARR_ELEMTYPE(array)),
format_type_be(element_type))));
+ this_ndims = ARR_NDIM(array);
+ /* temporarily ignore zero-dimensional subarrays */
+ if (this_ndims <= 0)
+ {
+ haveempty = true;
+ continue;
+ }
+
if (firstone)
{
/* Get sub-array details from first member */
- elem_ndims = ARR_NDIM(array);
+ elem_ndims = this_ndims;
ndims = elem_ndims + 1;
if (ndims <= 0 || ndims > MAXDIM)
ereport(ERROR,
@@ -2341,7 +2354,7 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
else
{
/* Check other sub-arrays are compatible */
- if (elem_ndims != ARR_NDIM(array) ||
+ if (elem_ndims != this_ndims ||
memcmp(elem_dims, ARR_DIMS(array),
elem_ndims * sizeof(int)) != 0 ||
memcmp(elem_lbs, ARR_LBOUND(array),
@@ -2356,13 +2369,29 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
subbitmaps[outer_nelems] = ARR_NULLBITMAP(array);
subbytes[outer_nelems] = ARR_SIZE(array) - ARR_DATA_OFFSET(array);
nbytes += subbytes[outer_nelems];
- subnitems[outer_nelems] = ArrayGetNItems(ARR_NDIM(array),
+ subnitems[outer_nelems] = ArrayGetNItems(this_ndims,
ARR_DIMS(array));
nitems += subnitems[outer_nelems];
havenulls |= ARR_HASNULL(array);
outer_nelems++;
}
+ /*
+ * If all items were null or empty arrays, return an empty array;
+ * otherwise, if some were and some weren't, raise error. (Note:
+ * we must special-case this somehow to avoid trying to generate
+ * a 1-D array formed from empty arrays. It's not ideal...)
+ */
+ if (haveempty)
+ {
+ if (ndims == 0) /* didn't find any nonempty array */
+ return PointerGetDatum(construct_empty_array(element_type));
+ ereport(ERROR,
+ (errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
+ errmsg("multidimensional arrays must have array "
+ "expressions with matching dimensions")));
+ }
+
/* setup for multi-D array */
dims[0] = outer_nelems;
lbs[0] = 1;
--
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