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Repair bug #2694 concerning an ARRAY[] construct whose inputs are empty

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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.
This commit is contained in:
Tom Lane 2006-11-06 18:21:47 +00:00
parent b4f5429fa8
commit fc8c5fbf5d
1 changed files with 36 additions and 3 deletions
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39
src/backend/executor/execQual.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.171.4.1 2005/10/19 22:51:26 tgl Exp $
* $PostgreSQL: pgsql/src/backend/executor/execQual.c,v 1.171.4.2 2006/11/06 18:21:47 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -2170,6 +2170,7 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
int *elem_dims = NULL;
int *elem_lbs = NULL;
bool firstone = true;
bool haveempty = false;
int i;
/* loop through and get data area from each element */
@ -2179,6 +2180,7 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
bool eisnull;
Datum arraydatum;
ArrayType *array;
int this_ndims;
int elem_ndatabytes;
arraydatum = ExecEvalExpr(e, econtext, &eisnull, NULL);
@ -2200,10 +2202,18 @@ 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,
@ -2221,7 +2231,7 @@ 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),
@ -2244,6 +2254,29 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
elem_ndatabytes);
}
/*
* If all items were 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 */
{
result = (ArrayType *) palloc(sizeof(ArrayType));
result->size = sizeof(ArrayType);
result->ndim = 0;
result->flags = 0;
result->elemtype = element_type;
return PointerGetDatum(result);
}
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;