Tweak palloc/repalloc to allow zero bytes to be requested, as per recent

proposal.  Eliminate several dozen now-unnecessary hacks to avoid palloc(0).
(It's likely there are more that I didn't find.)

2 files changed, 43 insertions, 49 deletions

diff --git a/src/pl/plpgsql/src/pl_exec.c b/src/pl/plpgsql/src/pl_exec.c
index 5a3d77a07c6..e479094099e 100644
--- a/src/pl/plpgsql/src/pl_exec.c
+++ b/src/pl/plpgsql/src/pl_exec.c
@@ -3,7 +3,7 @@
  *			  procedural language
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.104 2004/06/04 02:37:06 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/pl/plpgsql/src/pl_exec.c,v 1.105 2004/06/05 19:48:09 tgl Exp $
  *
  *	  This software is copyrighted by Jan Wieck - Hamburg.
  *
@@ -1942,10 +1942,8 @@ exec_prepare_plan(PLpgSQL_execstate * estate,
 	/*
 	 * We need a temporary argtypes array to load with data. (The finished
 	 * plan structure will contain a copy of it.)
-	 *
-	 * +1 is just to avoid palloc(0) error.
 	 */
-	argtypes = (Oid *) palloc(sizeof(Oid) * (expr->nparams + 1));
+	argtypes = (Oid *) palloc(expr->nparams * sizeof(Oid));
 
 	for (i = 0; i < expr->nparams; i++)
 	{
@@ -1998,8 +1996,8 @@ exec_stmt_execsql(PLpgSQL_execstate * estate,
 	/*
 	 * Now build up the values and nulls arguments for SPI_execp()
 	 */
-	values = palloc(sizeof(Datum) * (expr->nparams + 1));
-	nulls = palloc(expr->nparams + 1);
+	values = (Datum *) palloc(expr->nparams * sizeof(Datum));
+	nulls = (char *) palloc(expr->nparams * sizeof(char));
 
 	for (i = 0; i < expr->nparams; i++)
 	{
@@ -2479,8 +2477,8 @@ exec_stmt_open(PLpgSQL_execstate * estate, PLpgSQL_stmt_open * stmt)
 	 * refcursor opened with OPEN ... FOR SELECT ...;
 	 * ----------
 	 */
-	values = palloc(sizeof(Datum) * (query->nparams + 1));
-	nulls = palloc(query->nparams + 1);
+	values = (Datum *) palloc(query->nparams * sizeof(Datum));
+	nulls = (char *) palloc(query->nparams * sizeof(char));
 
 	for (i = 0; i < query->nparams; i++)
 	{
@@ -3324,8 +3322,8 @@ exec_run_select(PLpgSQL_execstate * estate,
 	/*
 	 * Now build up the values and nulls arguments for SPI_execp()
 	 */
-	values = palloc(sizeof(Datum) * (expr->nparams + 1));
-	nulls = palloc(expr->nparams + 1);
+	values = (Datum *) palloc(expr->nparams * sizeof(Datum));
+	nulls = (char *) palloc(expr->nparams * sizeof(char));
 
 	for (i = 0; i < expr->nparams; i++)
 	{
@@ -3528,8 +3526,7 @@ exec_move_row(PLpgSQL_execstate * estate,
 			/* If we have a tupdesc but no data, form an all-nulls tuple */
 			char	   *nulls;
 
-			/* +1 to avoid possible palloc(0) if no attributes */
-			nulls = (char *) palloc(tupdesc->natts * sizeof(char) + 1);
+			nulls = (char *) palloc(tupdesc->natts * sizeof(char));
 			memset(nulls, 'n', tupdesc->natts * sizeof(char));
 
 			rec->tup = heap_formtuple(tupdesc, NULL, nulls);
diff --git a/src/pl/plpython/plpython.c b/src/pl/plpython/plpython.c
index f660adf2973..d07af29c816 100644
--- a/src/pl/plpython/plpython.c
+++ b/src/pl/plpython/plpython.c
@@ -29,7 +29,7 @@
  * MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  *
  * IDENTIFICATION
- *	$PostgreSQL: pgsql/src/pl/plpython/plpython.c,v 1.47 2004/05/07 00:24:59 tgl Exp $
+ *	$PostgreSQL: pgsql/src/pl/plpython/plpython.c,v 1.48 2004/06/05 19:48:09 tgl Exp $
  *
  *********************************************************************
  */
@@ -531,10 +531,9 @@ PLy_modify_tuple(PLyProcedure * proc, PyObject * pltd, TriggerData *tdata,
 	plkeys = PyDict_Keys(plntup);
 	natts = PyList_Size(plkeys);
 
-	/* +1 to avoid palloc(0) on empty tuple */
-	modattrs = palloc(natts * sizeof(int) + 1);
-	modvalues = palloc(natts * sizeof(Datum) + 1);
-	modnulls = palloc(natts + 1);
+	modattrs = (int *) palloc(natts * sizeof(int));
+	modvalues = (Datum *) palloc(natts * sizeof(Datum));
+	modnulls = (char *) palloc(natts * sizeof(char));
 
 	tupdesc = tdata->tg_relation->rd_att;
 
@@ -2174,48 +2173,46 @@ PLy_spi_execute_plan(PyObject * ob, PyObject * list, int limit)
 		RERAISE_EXC();
 	}
 
-	if (nargs)
+	nulls = palloc(nargs * sizeof(char));
+
+	for (i = 0; i < nargs; i++)
 	{
-		nulls = palloc((nargs + 1) * sizeof(char));
+		PyObject   *elem,
+				   *so;
+		char	   *sv;
 
-		for (i = 0; i < nargs; i++)
+		elem = PySequence_GetItem(list, i);
+		if (elem != Py_None)
 		{
-			PyObject   *elem,
-					   *so;
-			char	   *sv;
+			so = PyObject_Str(elem);
+			sv = PyString_AsString(so);
 
-			elem = PySequence_GetItem(list, i);
-			if (elem != Py_None)
-			{
-				so = PyObject_Str(elem);
-				sv = PyString_AsString(so);
-
-				/*
-				 * FIXME -- if this can elog, we have leak
-				 */
-				plan->values[i] = FunctionCall3(&(plan->args[i].out.d.typfunc),
-												CStringGetDatum(sv),
-						   ObjectIdGetDatum(plan->args[i].out.d.typelem),
-												Int32GetDatum(-1));
+			/*
+			 * FIXME -- if this can elog, we have leak
+			 */
+			plan->values[i] =
+				FunctionCall3(&(plan->args[i].out.d.typfunc),
+							  CStringGetDatum(sv),
+							  ObjectIdGetDatum(plan->args[i].out.d.typelem),
+							  Int32GetDatum(-1));
 
-				Py_DECREF(so);
-				Py_DECREF(elem);
+			Py_DECREF(so);
+			Py_DECREF(elem);
 
-				nulls[i] = ' ';
-			}
-			else
-			{
-				Py_DECREF(elem);
-				plan->values[i] = (Datum) 0;
-				nulls[i] = 'n';
-			}
+			nulls[i] = ' ';
+		}
+		else
+		{
+			Py_DECREF(elem);
+			plan->values[i] = (Datum) 0;
+			nulls[i] = 'n';
 		}
-		nulls[i] = '\0';
 	}
-	else
-		nulls = NULL;
 
 	rv = SPI_execp(plan->plan, plan->values, nulls, limit);
+
+	pfree(nulls);
+
 	RESTORE_EXC();
 
 	for (i = 0; i < nargs; i++)