Remove obsoleted code relating to targetlist SRF evaluation.

Since 69f4b9c plain expression evaluation (and thus normal projection)
can't return sets of tuples anymore. Thus remove code dealing with
that possibility.

This will require adjustments in external code using
ExecEvalExpr()/ExecProject() - that should neither be hard nor very
common.

Author: Andres Freund and Tom Lane
Discussion: https://postgr.es/m/20160822214023.aaxz5l4igypowyri@alap3.anarazel.de

1 files changed, 247 insertions, 669 deletions

diff --git a/src/backend/executor/execQual.c b/src/backend/executor/execQual.c
index eed7e95c759..19dd0b264bc 100644
--- a/src/backend/executor/execQual.c
+++ b/src/backend/executor/execQual.c
@@ -64,40 +64,40 @@
 /* static function decls */
 static Datum ExecEvalArrayRef(ArrayRefExprState *astate,
 				 ExprContext *econtext,
-				 bool *isNull, ExprDoneCond *isDone);
+				 bool *isNull);
 static bool isAssignmentIndirectionExpr(ExprState *exprstate);
 static Datum ExecEvalAggref(AggrefExprState *aggref,
 			   ExprContext *econtext,
-			   bool *isNull, ExprDoneCond *isDone);
+			   bool *isNull);
 static Datum ExecEvalWindowFunc(WindowFuncExprState *wfunc,
 				   ExprContext *econtext,
-				   bool *isNull, ExprDoneCond *isDone);
+				   bool *isNull);
 static Datum ExecEvalScalarVar(ExprState *exprstate, ExprContext *econtext,
-				  bool *isNull, ExprDoneCond *isDone);
+				  bool *isNull);
 static Datum ExecEvalScalarVarFast(ExprState *exprstate, ExprContext *econtext,
-					  bool *isNull, ExprDoneCond *isDone);
+					  bool *isNull);
 static Datum ExecEvalWholeRowVar(WholeRowVarExprState *wrvstate,
 					ExprContext *econtext,
-					bool *isNull, ExprDoneCond *isDone);
+					bool *isNull);
 static Datum ExecEvalWholeRowFast(WholeRowVarExprState *wrvstate,
 					 ExprContext *econtext,
-					 bool *isNull, ExprDoneCond *isDone);
+					 bool *isNull);
 static Datum ExecEvalWholeRowSlow(WholeRowVarExprState *wrvstate,
 					 ExprContext *econtext,
-					 bool *isNull, ExprDoneCond *isDone);
+					 bool *isNull);
 static Datum ExecEvalConst(ExprState *exprstate, ExprContext *econtext,
-			  bool *isNull, ExprDoneCond *isDone);
+			  bool *isNull);
 static Datum ExecEvalParamExec(ExprState *exprstate, ExprContext *econtext,
-				  bool *isNull, ExprDoneCond *isDone);
+				  bool *isNull);
 static Datum ExecEvalParamExtern(ExprState *exprstate, ExprContext *econtext,
-					bool *isNull, ExprDoneCond *isDone);
+					bool *isNull);
 static void init_fcache(Oid foid, Oid input_collation, FuncExprState *fcache,
 			MemoryContext fcacheCxt, bool allowSRF, bool needDescForSRF);
 static void ShutdownFuncExpr(Datum arg);
 static TupleDesc get_cached_rowtype(Oid type_id, int32 typmod,
 				   TupleDesc *cache_field, ExprContext *econtext);
 static void ShutdownTupleDescRef(Datum arg);
-static ExprDoneCond ExecEvalFuncArgs(FunctionCallInfo fcinfo,
+static void ExecEvalFuncArgs(FunctionCallInfo fcinfo,
 				 List *argList, ExprContext *econtext);
 static void ExecPrepareTuplestoreResult(FuncExprState *fcache,
 							ExprContext *econtext,
@@ -106,85 +106,85 @@ static void ExecPrepareTuplestoreResult(FuncExprState *fcache,
 static void tupledesc_match(TupleDesc dst_tupdesc, TupleDesc src_tupdesc);
 static Datum ExecMakeFunctionResultNoSets(FuncExprState *fcache,
 							 ExprContext *econtext,
-							 bool *isNull, ExprDoneCond *isDone);
+							 bool *isNull);
 static Datum ExecEvalFunc(FuncExprState *fcache, ExprContext *econtext,
-			 bool *isNull, ExprDoneCond *isDone);
+			 bool *isNull);
 static Datum ExecEvalOper(FuncExprState *fcache, ExprContext *econtext,
-			 bool *isNull, ExprDoneCond *isDone);
+			 bool *isNull);
 static Datum ExecEvalDistinct(FuncExprState *fcache, ExprContext *econtext,
-				 bool *isNull, ExprDoneCond *isDone);
+				 bool *isNull);
 static Datum ExecEvalScalarArrayOp(ScalarArrayOpExprState *sstate,
 					  ExprContext *econtext,
-					  bool *isNull, ExprDoneCond *isDone);
+					  bool *isNull);
 static Datum ExecEvalNot(BoolExprState *notclause, ExprContext *econtext,
-			bool *isNull, ExprDoneCond *isDone);
+			bool *isNull);
 static Datum ExecEvalOr(BoolExprState *orExpr, ExprContext *econtext,
-		   bool *isNull, ExprDoneCond *isDone);
+		   bool *isNull);
 static Datum ExecEvalAnd(BoolExprState *andExpr, ExprContext *econtext,
-			bool *isNull, ExprDoneCond *isDone);
+			bool *isNull);
 static Datum ExecEvalConvertRowtype(ConvertRowtypeExprState *cstate,
 					   ExprContext *econtext,
-					   bool *isNull, ExprDoneCond *isDone);
+					   bool *isNull);
 static Datum ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext,
-			 bool *isNull, ExprDoneCond *isDone);
+			 bool *isNull);
 static Datum ExecEvalCaseTestExpr(ExprState *exprstate,
 					 ExprContext *econtext,
-					 bool *isNull, ExprDoneCond *isDone);
+					 bool *isNull);
 static Datum ExecEvalArray(ArrayExprState *astate,
 			  ExprContext *econtext,
-			  bool *isNull, ExprDoneCond *isDone);
+			  bool *isNull);
 static Datum ExecEvalRow(RowExprState *rstate,
 			ExprContext *econtext,
-			bool *isNull, ExprDoneCond *isDone);
+			bool *isNull);
 static Datum ExecEvalRowCompare(RowCompareExprState *rstate,
 				   ExprContext *econtext,
-				   bool *isNull, ExprDoneCond *isDone);
+				   bool *isNull);
 static Datum ExecEvalCoalesce(CoalesceExprState *coalesceExpr,
 				 ExprContext *econtext,
-				 bool *isNull, ExprDoneCond *isDone);
+				 bool *isNull);
 static Datum ExecEvalMinMax(MinMaxExprState *minmaxExpr,
 			   ExprContext *econtext,
-			   bool *isNull, ExprDoneCond *isDone);
+			   bool *isNull);
 static Datum ExecEvalSQLValueFunction(ExprState *svfExpr,
 						 ExprContext *econtext,
-						 bool *isNull, ExprDoneCond *isDone);
+						 bool *isNull);
 static Datum ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
-			bool *isNull, ExprDoneCond *isDone);
+			bool *isNull);
 static Datum ExecEvalNullIf(FuncExprState *nullIfExpr,
 			   ExprContext *econtext,
-			   bool *isNull, ExprDoneCond *isDone);
+			   bool *isNull);
 static Datum ExecEvalNullTest(NullTestState *nstate,
 				 ExprContext *econtext,
-				 bool *isNull, ExprDoneCond *isDone);
+				 bool *isNull);
 static Datum ExecEvalBooleanTest(GenericExprState *bstate,
 					ExprContext *econtext,
-					bool *isNull, ExprDoneCond *isDone);
+					bool *isNull);
 static Datum ExecEvalCoerceToDomain(CoerceToDomainState *cstate,
 					   ExprContext *econtext,
-					   bool *isNull, ExprDoneCond *isDone);
+					   bool *isNull);
 static Datum ExecEvalCoerceToDomainValue(ExprState *exprstate,
 							ExprContext *econtext,
-							bool *isNull, ExprDoneCond *isDone);
+							bool *isNull);
 static Datum ExecEvalFieldSelect(FieldSelectState *fstate,
 					ExprContext *econtext,
-					bool *isNull, ExprDoneCond *isDone);
+					bool *isNull);
 static Datum ExecEvalFieldStore(FieldStoreState *fstate,
 				   ExprContext *econtext,
-				   bool *isNull, ExprDoneCond *isDone);
+				   bool *isNull);
 static Datum ExecEvalRelabelType(GenericExprState *exprstate,
 					ExprContext *econtext,
-					bool *isNull, ExprDoneCond *isDone);
+					bool *isNull);
 static Datum ExecEvalCoerceViaIO(CoerceViaIOState *iostate,
 					ExprContext *econtext,
-					bool *isNull, ExprDoneCond *isDone);
+					bool *isNull);
 static Datum ExecEvalArrayCoerceExpr(ArrayCoerceExprState *astate,
 						ExprContext *econtext,
-						bool *isNull, ExprDoneCond *isDone);
+						bool *isNull);
 static Datum ExecEvalCurrentOfExpr(ExprState *exprstate, ExprContext *econtext,
-					  bool *isNull, ExprDoneCond *isDone);
+					  bool *isNull);
 static Datum ExecEvalGroupingFuncExpr(GroupingFuncExprState *gstate,
 						 ExprContext *econtext,
-						 bool *isNull, ExprDoneCond *isDone);
+						 bool *isNull);
 
 
 /* ----------------------------------------------------------------
@@ -195,8 +195,7 @@ static Datum ExecEvalGroupingFuncExpr(GroupingFuncExprState *gstate,
  * Each of the following routines having the signature
  *		Datum ExecEvalFoo(ExprState *expression,
  *						  ExprContext *econtext,
- *						  bool *isNull,
- *						  ExprDoneCond *isDone);
+ *						  bool *isNull);
  * is responsible for evaluating one type or subtype of ExprState node.
  * They are normally called via the ExecEvalExpr macro, which makes use of
  * the function pointer set up when the ExprState node was built by
@@ -220,22 +219,6 @@ static Datum ExecEvalGroupingFuncExpr(GroupingFuncExprState *gstate,
  *		return value: Datum value of result
  *		*isNull: set to TRUE if result is NULL (actual return value is
  *				 meaningless if so); set to FALSE if non-null result
- *		*isDone: set to indicator of set-result status
- *
- * A caller that can only accept a singleton (non-set) result should pass
- * NULL for isDone; if the expression computes a set result then an error
- * will be reported via ereport.  If the caller does pass an isDone pointer
- * then *isDone is set to one of these three states:
- *		ExprSingleResult		singleton result (not a set)
- *		ExprMultipleResult		return value is one element of a set
- *		ExprEndResult			there are no more elements in the set
- * When ExprMultipleResult is returned, the caller should invoke
- * ExecEvalExpr() repeatedly until ExprEndResult is returned.  ExprEndResult
- * is returned after the last real set element.  For convenience isNull will
- * always be set TRUE when ExprEndResult is returned, but this should not be
- * taken as indicating a NULL element of the set.  Note that these return
- * conventions allow us to distinguish among a singleton NULL, a NULL element
- * of a set, and an empty set.
  *
  * The caller should already have switched into the temporary memory
  * context econtext->ecxt_per_tuple_memory.  The convenience entry point
@@ -260,8 +243,7 @@ static Datum ExecEvalGroupingFuncExpr(GroupingFuncExprState *gstate,
 static Datum
 ExecEvalArrayRef(ArrayRefExprState *astate,
 				 ExprContext *econtext,
-				 bool *isNull,
-				 ExprDoneCond *isDone)
+				 bool *isNull)
 {
 	ArrayRef   *arrayRef = (ArrayRef *) astate->xprstate.expr;
 	Datum		array_source;
@@ -278,8 +260,7 @@ ExecEvalArrayRef(ArrayRefExprState *astate,
 
 	array_source = ExecEvalExpr(astate->refexpr,
 								econtext,
-								isNull,
-								isDone);
+								isNull);
 
 	/*
 	 * If refexpr yields NULL, and it's a fetch, then result is NULL. In the
@@ -287,8 +268,6 @@ ExecEvalArrayRef(ArrayRefExprState *astate,
 	 */
 	if (*isNull)
 	{
-		if (isDone && *isDone == ExprEndResult)
-			return (Datum) NULL;	/* end of set result */
 		if (!isAssignment)
 			return (Datum) NULL;
 	}
@@ -314,8 +293,7 @@ ExecEvalArrayRef(ArrayRefExprState *astate,
 
 		upper.indx[i++] = DatumGetInt32(ExecEvalExpr(eltstate,
 													 econtext,
-													 &eisnull,
-													 NULL));
+													 &eisnull));
 		/* If any index expr yields NULL, result is NULL or error */
 		if (eisnull)
 		{
@@ -350,8 +328,7 @@ ExecEvalArrayRef(ArrayRefExprState *astate,
 
 			lower.indx[j++] = DatumGetInt32(ExecEvalExpr(eltstate,
 														 econtext,
-														 &eisnull,
-														 NULL));
+														 &eisnull));
 			/* If any index expr yields NULL, result is NULL or error */
 			if (eisnull)
 			{
@@ -438,8 +415,7 @@ ExecEvalArrayRef(ArrayRefExprState *astate,
 		 */
 		sourceData = ExecEvalExpr(astate->refassgnexpr,
 								  econtext,
-								  &eisnull,
-								  NULL);
+								  &eisnull);
 
 		econtext->caseValue_datum = save_datum;
 		econtext->caseValue_isNull = save_isNull;
@@ -542,11 +518,8 @@ isAssignmentIndirectionExpr(ExprState *exprstate)
  */
 static Datum
 ExecEvalAggref(AggrefExprState *aggref, ExprContext *econtext,
-			   bool *isNull, ExprDoneCond *isDone)
+			   bool *isNull)
 {
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	if (econtext->ecxt_aggvalues == NULL)		/* safety check */
 		elog(ERROR, "no aggregates in this expression context");
 
@@ -563,11 +536,8 @@ ExecEvalAggref(AggrefExprState *aggref, ExprContext *econtext,
  */
 static Datum
 ExecEvalWindowFunc(WindowFuncExprState *wfunc, ExprContext *econtext,
-				   bool *isNull, ExprDoneCond *isDone)
+				   bool *isNull)
 {
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	if (econtext->ecxt_aggvalues == NULL)		/* safety check */
 		elog(ERROR, "no window functions in this expression context");
 
@@ -588,15 +558,12 @@ ExecEvalWindowFunc(WindowFuncExprState *wfunc, ExprContext *econtext,
  */
 static Datum
 ExecEvalScalarVar(ExprState *exprstate, ExprContext *econtext,
-				  bool *isNull, ExprDoneCond *isDone)
+				  bool *isNull)
 {
 	Var		   *variable = (Var *) exprstate->expr;
 	TupleTableSlot *slot;
 	AttrNumber	attnum;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	/* Get the input slot and attribute number we want */
 	switch (variable->varno)
 	{
@@ -677,15 +644,12 @@ ExecEvalScalarVar(ExprState *exprstate, ExprContext *econtext,
  */
 static Datum
 ExecEvalScalarVarFast(ExprState *exprstate, ExprContext *econtext,
-					  bool *isNull, ExprDoneCond *isDone)
+					  bool *isNull)
 {
 	Var		   *variable = (Var *) exprstate->expr;
 	TupleTableSlot *slot;
 	AttrNumber	attnum;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	/* Get the input slot and attribute number we want */
 	switch (variable->varno)
 	{
@@ -725,7 +689,7 @@ ExecEvalScalarVarFast(ExprState *exprstate, ExprContext *econtext,
  */
 static Datum
 ExecEvalWholeRowVar(WholeRowVarExprState *wrvstate, ExprContext *econtext,
-					bool *isNull, ExprDoneCond *isDone)
+					bool *isNull)
 {
 	Var		   *variable = (Var *) wrvstate->xprstate.expr;
 	TupleTableSlot *slot;
@@ -733,9 +697,6 @@ ExecEvalWholeRowVar(WholeRowVarExprState *wrvstate, ExprContext *econtext,
 	MemoryContext oldcontext;
 	bool		needslow = false;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	/* This was checked by ExecInitExpr */
 	Assert(variable->varattno == InvalidAttrNumber);
 
@@ -941,7 +902,7 @@ ExecEvalWholeRowVar(WholeRowVarExprState *wrvstate, ExprContext *econtext,
 
 	/* Fetch the value */
 	return (*wrvstate->xprstate.evalfunc) ((ExprState *) wrvstate, econtext,
-										   isNull, isDone);
+										   isNull);
 }
 
 /* ----------------------------------------------------------------
@@ -952,14 +913,12 @@ ExecEvalWholeRowVar(WholeRowVarExprState *wrvstate, ExprContext *econtext,
  */
 static Datum
 ExecEvalWholeRowFast(WholeRowVarExprState *wrvstate, ExprContext *econtext,
-					 bool *isNull, ExprDoneCond *isDone)
+					 bool *isNull)
 {
 	Var		   *variable = (Var *) wrvstate->xprstate.expr;
 	TupleTableSlot *slot;
 	HeapTupleHeader dtuple;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
 	*isNull = false;
 
 	/* Get the input slot we want */
@@ -1008,7 +967,7 @@ ExecEvalWholeRowFast(WholeRowVarExprState *wrvstate, ExprContext *econtext,
  */
 static Datum
 ExecEvalWholeRowSlow(WholeRowVarExprState *wrvstate, ExprContext *econtext,
-					 bool *isNull, ExprDoneCond *isDone)
+					 bool *isNull)
 {
 	Var		   *variable = (Var *) wrvstate->xprstate.expr;
 	TupleTableSlot *slot;
@@ -1018,8 +977,6 @@ ExecEvalWholeRowSlow(WholeRowVarExprState *wrvstate, ExprContext *econtext,
 	HeapTupleHeader dtuple;
 	int			i;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
 	*isNull = false;
 
 	/* Get the input slot we want */
@@ -1097,13 +1054,10 @@ ExecEvalWholeRowSlow(WholeRowVarExprState *wrvstate, ExprContext *econtext,
  */
 static Datum
 ExecEvalConst(ExprState *exprstate, ExprContext *econtext,
-			  bool *isNull, ExprDoneCond *isDone)
+			  bool *isNull)
 {
 	Const	   *con = (Const *) exprstate->expr;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	*isNull = con->constisnull;
 	return con->constvalue;
 }
@@ -1116,15 +1070,12 @@ ExecEvalConst(ExprState *exprstate, ExprContext *econtext,
  */
 static Datum
 ExecEvalParamExec(ExprState *exprstate, ExprContext *econtext,
-				  bool *isNull, ExprDoneCond *isDone)
+				  bool *isNull)
 {
 	Param	   *expression = (Param *) exprstate->expr;
 	int			thisParamId = expression->paramid;
 	ParamExecData *prm;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	/*
 	 * PARAM_EXEC params (internal executor parameters) are stored in the
 	 * ecxt_param_exec_vals array, and can be accessed by array index.
@@ -1149,15 +1100,12 @@ ExecEvalParamExec(ExprState *exprstate, ExprContext *econtext,
  */
 static Datum
 ExecEvalParamExtern(ExprState *exprstate, ExprContext *econtext,
-					bool *isNull, ExprDoneCond *isDone)
+					bool *isNull)
 {
 	Param	   *expression = (Param *) exprstate->expr;
 	int			thisParamId = expression->paramid;
 	ParamListInfo paramInfo = econtext->ecxt_param_list_info;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	/*
 	 * PARAM_EXTERN parameters must be sought in ecxt_param_list_info.
 	 */
@@ -1421,7 +1369,6 @@ init_fcache(Oid foid, Oid input_collation, FuncExprState *fcache,
 	/* Initialize additional state */
 	fcache->funcResultStore = NULL;
 	fcache->funcResultSlot = NULL;
-	fcache->setArgsValid = false;
 	fcache->shutdown_reg = false;
 }
 
@@ -1508,47 +1455,26 @@ ShutdownTupleDescRef(Datum arg)
 /*
  * Evaluate arguments for a function.
  */
-static ExprDoneCond
+static void
 ExecEvalFuncArgs(FunctionCallInfo fcinfo,
 				 List *argList,
 				 ExprContext *econtext)
 {
-	ExprDoneCond argIsDone;
 	int			i;
 	ListCell   *arg;
 
-	argIsDone = ExprSingleResult;		/* default assumption */
-
 	i = 0;
 	foreach(arg, argList)
 	{
 		ExprState  *argstate = (ExprState *) lfirst(arg);
-		ExprDoneCond thisArgIsDone;
 
 		fcinfo->arg[i] = ExecEvalExpr(argstate,
 									  econtext,
-									  &fcinfo->argnull[i],
-									  &thisArgIsDone);
-
-		if (thisArgIsDone != ExprSingleResult)
-		{
-			/*
-			 * We allow only one argument to have a set value; we'd need much
-			 * more complexity to keep track of multiple set arguments (cf.
-			 * ExecTargetList) and it doesn't seem worth it.
-			 */
-			if (argIsDone != ExprSingleResult)
-				ereport(ERROR,
-						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-						 errmsg("functions and operators can take at most one set argument")));
-			argIsDone = thisArgIsDone;
-		}
+									  &fcinfo->argnull[i]);
 		i++;
 	}
 
 	Assert(i == fcinfo->nargs);
-
-	return argIsDone;
 }
 
 /*
@@ -1694,9 +1620,8 @@ ExecMakeFunctionResultSet(FuncExprState *fcache,
 	Datum		result;
 	FunctionCallInfo fcinfo;
 	PgStat_FunctionCallUsage fcusage;
-	ReturnSetInfo rsinfo;		/* for functions returning sets */
-	ExprDoneCond argDone;
-	bool		hasSetArg;
+	ReturnSetInfo rsinfo;
+	bool		callit;
 	int			i;
 
 restart:
@@ -1727,6 +1652,9 @@ restart:
 		else
 			elog(ERROR, "unrecognized node type: %d",
 				 (int) nodeTag(fcache->xprstate.expr));
+
+		/* shouldn't get here otherwise */
+		Assert(fcache->func.fn_retset);
 	}
 
 	/*
@@ -1736,7 +1664,6 @@ restart:
 	 */
 	if (fcache->funcResultStore)
 	{
-		Assert(isDone);			/* it was provided before ... */
 		if (tuplestore_gettupleslot(fcache->funcResultStore, true, false,
 									fcache->funcResultSlot))
 		{
@@ -1756,15 +1683,9 @@ restart:
 		/* Exhausted the tuplestore, so clean up */
 		tuplestore_end(fcache->funcResultStore);
 		fcache->funcResultStore = NULL;
-		/* We are done unless there was a set-valued argument */
-		if (!fcache->setHasSetArg)
-		{
-			*isDone = ExprEndResult;
-			*isNull = true;
-			return (Datum) 0;
-		}
-		/* If there was, continue evaluating the argument values */
-		Assert(!fcache->setArgsValid);
+		*isDone = ExprEndResult;
+		*isNull = true;
+		return (Datum) 0;
 	}
 
 	/*
@@ -1776,18 +1697,9 @@ restart:
 	fcinfo = &fcache->fcinfo_data;
 	arguments = fcache->args;
 	if (!fcache->setArgsValid)
-	{
-		argDone = ExecEvalFuncArgs(fcinfo, arguments, econtext);
-		if (argDone != ExprSingleResult)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("set-valued function called in context that cannot accept a set")));
-		hasSetArg = false;
-	}
+		ExecEvalFuncArgs(fcinfo, arguments, econtext);
 	else
 	{
-		/* Re-use callinfo from previous evaluation */
-		hasSetArg = fcache->setHasSetArg;
 		/* Reset flag (we may set it again below) */
 		fcache->setArgsValid = false;
 	}
@@ -1795,213 +1707,105 @@ restart:
 	/*
 	 * Now call the function, passing the evaluated parameter values.
 	 */
-	if (fcache->func.fn_retset || hasSetArg)
-	{
-		/*
-		 * We need to return a set result.  Complain if caller not ready to
-		 * accept one.
-		 */
-		if (isDone == NULL)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("set-valued function called in context that cannot accept a set")));
 
-		/*
-		 * Prepare a resultinfo node for communication.  If the function
-		 * doesn't itself return set, we don't pass the resultinfo to the
-		 * function, but we need to fill it in anyway for internal use.
-		 */
-		if (fcache->func.fn_retset)
-			fcinfo->resultinfo = (Node *) &rsinfo;
-		rsinfo.type = T_ReturnSetInfo;
-		rsinfo.econtext = econtext;
-		rsinfo.expectedDesc = fcache->funcResultDesc;
-		rsinfo.allowedModes = (int) (SFRM_ValuePerCall | SFRM_Materialize);
-		/* note we do not set SFRM_Materialize_Random or _Preferred */
-		rsinfo.returnMode = SFRM_ValuePerCall;
-		/* isDone is filled below */
-		rsinfo.setResult = NULL;
-		rsinfo.setDesc = NULL;
+	/* Prepare a resultinfo node for communication. */
+	fcinfo->resultinfo = (Node *) &rsinfo;
+	rsinfo.type = T_ReturnSetInfo;
+	rsinfo.econtext = econtext;
+	rsinfo.expectedDesc = fcache->funcResultDesc;
+	rsinfo.allowedModes = (int) (SFRM_ValuePerCall | SFRM_Materialize);
+	/* note we do not set SFRM_Materialize_Random or _Preferred */
+	rsinfo.returnMode = SFRM_ValuePerCall;
+	/* isDone is filled below */
+	rsinfo.setResult = NULL;
+	rsinfo.setDesc = NULL;
 
-		/*
-		 * This loop handles the situation where we have both a set argument
-		 * and a set-valued function.  Once we have exhausted the function's
-		 * value(s) for a particular argument value, we have to get the next
-		 * argument value and start the function over again. We might have to
-		 * do it more than once, if the function produces an empty result set
-		 * for a particular input value.
-		 */
-		for (;;)
+	/*
+	 * If function is strict, and there are any NULL arguments, skip calling
+	 * the function.
+	 */
+	callit = true;
+	if (fcache->func.fn_strict)
+	{
+		for (i = 0; i < fcinfo->nargs; i++)
 		{
-			/*
-			 * If function is strict, and there are any NULL arguments, skip
-			 * calling the function (at least for this set of args).
-			 */
-			bool		callit = true;
-
-			if (fcache->func.fn_strict)
-			{
-				for (i = 0; i < fcinfo->nargs; i++)
-				{
-					if (fcinfo->argnull[i])
-					{
-						callit = false;
-						break;
-					}
-				}
-			}
-
-			if (callit)
-			{
-				pgstat_init_function_usage(fcinfo, &fcusage);
-
-				fcinfo->isnull = false;
-				rsinfo.isDone = ExprSingleResult;
-				result = FunctionCallInvoke(fcinfo);
-				*isNull = fcinfo->isnull;
-				*isDone = rsinfo.isDone;
-
-				pgstat_end_function_usage(&fcusage,
-										rsinfo.isDone != ExprMultipleResult);
-			}
-			else if (fcache->func.fn_retset)
-			{
-				/* for a strict SRF, result for NULL is an empty set */
-				result = (Datum) 0;
-				*isNull = true;
-				*isDone = ExprEndResult;
-			}
-			else
-			{
-				/* for a strict non-SRF, result for NULL is a NULL */
-				result = (Datum) 0;
-				*isNull = true;
-				*isDone = ExprSingleResult;
-			}
-
-			/* Which protocol does function want to use? */
-			if (rsinfo.returnMode == SFRM_ValuePerCall)
-			{
-				if (*isDone != ExprEndResult)
-				{
-					/*
-					 * Got a result from current argument. If function itself
-					 * returns set, save the current argument values to re-use
-					 * on the next call.
-					 */
-					if (fcache->func.fn_retset &&
-						*isDone == ExprMultipleResult)
-					{
-						fcache->setHasSetArg = hasSetArg;
-						fcache->setArgsValid = true;
-						/* Register cleanup callback if we didn't already */
-						if (!fcache->shutdown_reg)
-						{
-							RegisterExprContextCallback(econtext,
-														ShutdownFuncExpr,
-													PointerGetDatum(fcache));
-							fcache->shutdown_reg = true;
-						}
-					}
-
-					/*
-					 * Make sure we say we are returning a set, even if the
-					 * function itself doesn't return sets.
-					 */
-					if (hasSetArg)
-						*isDone = ExprMultipleResult;
-					break;
-				}
-			}
-			else if (rsinfo.returnMode == SFRM_Materialize)
+			if (fcinfo->argnull[i])
 			{
-				/* check we're on the same page as the function author */
-				if (rsinfo.isDone != ExprSingleResult)
-					ereport(ERROR,
-							(errcode(ERRCODE_E_R_I_E_SRF_PROTOCOL_VIOLATED),
-							 errmsg("table-function protocol for materialize mode was not followed")));
-				if (rsinfo.setResult != NULL)
-				{
-					/* prepare to return values from the tuplestore */
-					ExecPrepareTuplestoreResult(fcache, econtext,
-												rsinfo.setResult,
-												rsinfo.setDesc);
-					/* remember whether we had set arguments */
-					fcache->setHasSetArg = hasSetArg;
-					/* loop back to top to start returning from tuplestore */
-					goto restart;
-				}
-				/* if setResult was left null, treat it as empty set */
-				*isDone = ExprEndResult;
-				*isNull = true;
-				result = (Datum) 0;
+				callit = false;
+				break;
 			}
-			else
-				ereport(ERROR,
-						(errcode(ERRCODE_E_R_I_E_SRF_PROTOCOL_VIOLATED),
-						 errmsg("unrecognized table-function returnMode: %d",
-								(int) rsinfo.returnMode)));
-
-			/* Else, done with this argument */
-			if (!hasSetArg)
-				break;			/* input not a set, so done */
+		}
+	}
 
-			/* Re-eval args to get the next element of the input set */
-			argDone = ExecEvalFuncArgs(fcinfo, arguments, econtext);
+	if (callit)
+	{
+		pgstat_init_function_usage(fcinfo, &fcusage);
 
-			if (argDone != ExprMultipleResult)
-			{
-				/* End of argument set, so we're done. */
-				*isNull = true;
-				*isDone = ExprEndResult;
-				result = (Datum) 0;
-				break;
-			}
+		fcinfo->isnull = false;
+		rsinfo.isDone = ExprSingleResult;
+		result = FunctionCallInvoke(fcinfo);
+		*isNull = fcinfo->isnull;
+		*isDone = rsinfo.isDone;
 
-			/*
-			 * If we reach here, loop around to run the function on the new
-			 * argument.
-			 */
-		}
+		pgstat_end_function_usage(&fcusage,
+								  rsinfo.isDone != ExprMultipleResult);
 	}
 	else
 	{
-		/*
-		 * Non-set case: much easier.
-		 *
-		 * In common cases, this code path is unreachable because we'd have
-		 * selected ExecMakeFunctionResultNoSets instead.  However, it's
-		 * possible to get here if an argument sometimes produces set results
-		 * and sometimes scalar results.  For example, a CASE expression might
-		 * call a set-returning function in only some of its arms.
-		 */
-		if (isDone)
-			*isDone = ExprSingleResult;
+		/* for a strict SRF, result for NULL is an empty set */
+		result = (Datum) 0;
+		*isNull = true;
+		*isDone = ExprEndResult;
+	}
 
-		/*
-		 * If function is strict, and there are any NULL arguments, skip
-		 * calling the function and return NULL.
-		 */
-		if (fcache->func.fn_strict)
+	/* Which protocol does function want to use? */
+	if (rsinfo.returnMode == SFRM_ValuePerCall)
+	{
+		if (*isDone != ExprEndResult)
 		{
-			for (i = 0; i < fcinfo->nargs; i++)
+			/*
+			 * Save the current argument values to re-use on the next call.
+			 */
+			if (*isDone == ExprMultipleResult)
 			{
-				if (fcinfo->argnull[i])
+				fcache->setArgsValid = true;
+				/* Register cleanup callback if we didn't already */
+				if (!fcache->shutdown_reg)
 				{
-					*isNull = true;
-					return (Datum) 0;
+					RegisterExprContextCallback(econtext,
+												ShutdownFuncExpr,
+												PointerGetDatum(fcache));
+					fcache->shutdown_reg = true;
 				}
 			}
 		}
-
-		pgstat_init_function_usage(fcinfo, &fcusage);
-
-		fcinfo->isnull = false;
-		result = FunctionCallInvoke(fcinfo);
-		*isNull = fcinfo->isnull;
-
-		pgstat_end_function_usage(&fcusage, true);
 	}
+	else if (rsinfo.returnMode == SFRM_Materialize)
+	{
+		/* check we're on the same page as the function author */
+		if (rsinfo.isDone != ExprSingleResult)
+			ereport(ERROR,
+					(errcode(ERRCODE_E_R_I_E_SRF_PROTOCOL_VIOLATED),
+					 errmsg("table-function protocol for materialize mode was not followed")));
+		if (rsinfo.setResult != NULL)
+		{
+			/* prepare to return values from the tuplestore */
+			ExecPrepareTuplestoreResult(fcache, econtext,
+										rsinfo.setResult,
+										rsinfo.setDesc);
+			/* loop back to top to start returning from tuplestore */
+			goto restart;
+		}
+		/* if setResult was left null, treat it as empty set */
+		*isDone = ExprEndResult;
+		*isNull = true;
+		result = (Datum) 0;
+	}
+	else
+		ereport(ERROR,
+				(errcode(ERRCODE_E_R_I_E_SRF_PROTOCOL_VIOLATED),
+				 errmsg("unrecognized table-function returnMode: %d",
+						(int) rsinfo.returnMode)));
 
 	return result;
 }
@@ -2015,8 +1819,7 @@ restart:
 static Datum
 ExecMakeFunctionResultNoSets(FuncExprState *fcache,
 							 ExprContext *econtext,
-							 bool *isNull,
-							 ExprDoneCond *isDone)
+							 bool *isNull)
 {
 	ListCell   *arg;
 	Datum		result;
@@ -2027,9 +1830,6 @@ ExecMakeFunctionResultNoSets(FuncExprState *fcache,
 	/* Guard against stack overflow due to overly complex expressions */
 	check_stack_depth();
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	/* inlined, simplified version of ExecEvalFuncArgs */
 	fcinfo = &fcache->fcinfo_data;
 	i = 0;
@@ -2039,8 +1839,7 @@ ExecMakeFunctionResultNoSets(FuncExprState *fcache,
 
 		fcinfo->arg[i] = ExecEvalExpr(argstate,
 									  econtext,
-									  &fcinfo->argnull[i],
-									  NULL);
+									  &fcinfo->argnull[i]);
 		i++;
 	}
 
@@ -2137,7 +1936,6 @@ ExecMakeTableFunctionResult(ExprState *funcexpr,
 		IsA(funcexpr->expr, FuncExpr))
 	{
 		FuncExprState *fcache = (FuncExprState *) funcexpr;
-		ExprDoneCond argDone;
 
 		/*
 		 * This path is similar to ExecMakeFunctionResultSet.
@@ -2172,15 +1970,9 @@ ExecMakeTableFunctionResult(ExprState *funcexpr,
 		 */
 		MemoryContextReset(argContext);
 		oldcontext = MemoryContextSwitchTo(argContext);
-		argDone = ExecEvalFuncArgs(&fcinfo, fcache->args, econtext);
+		ExecEvalFuncArgs(&fcinfo, fcache->args, econtext);
 		MemoryContextSwitchTo(oldcontext);
 
-		/* We don't allow sets in the arguments of the table function */
-		if (argDone != ExprSingleResult)
-			ereport(ERROR,
-					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-					 errmsg("set-valued function called in context that cannot accept a set")));
-
 		/*
 		 * If function is strict, and there are any NULL arguments, skip
 		 * calling the function and act like it returned NULL (or an empty
@@ -2240,8 +2032,8 @@ ExecMakeTableFunctionResult(ExprState *funcexpr,
 		}
 		else
 		{
-			result = ExecEvalExpr(funcexpr, econtext,
-								  &fcinfo.isnull, &rsinfo.isDone);
+			result = ExecEvalExpr(funcexpr, econtext, &fcinfo.isnull);
+			rsinfo.isDone = ExprSingleResult;
 		}
 
 		/* Which protocol does function want to use? */
@@ -2435,8 +2227,7 @@ no_function_result:
 static Datum
 ExecEvalFunc(FuncExprState *fcache,
 			 ExprContext *econtext,
-			 bool *isNull,
-			 ExprDoneCond *isDone)
+			 bool *isNull)
 {
 	/* This is called only the first time through */
 	FuncExpr   *func = (FuncExpr *) fcache->xprstate.expr;
@@ -2447,7 +2238,7 @@ ExecEvalFunc(FuncExprState *fcache,
 
 	/* Change the evalfunc pointer to save a few cycles in additional calls */
 	fcache->xprstate.evalfunc = (ExprStateEvalFunc) ExecMakeFunctionResultNoSets;
-	return ExecMakeFunctionResultNoSets(fcache, econtext, isNull, isDone);
+	return ExecMakeFunctionResultNoSets(fcache, econtext, isNull);
 }
 
 /* ----------------------------------------------------------------
@@ -2457,8 +2248,7 @@ ExecEvalFunc(FuncExprState *fcache,
 static Datum
 ExecEvalOper(FuncExprState *fcache,
 			 ExprContext *econtext,
-			 bool *isNull,
-			 ExprDoneCond *isDone)
+			 bool *isNull)
 {
 	/* This is called only the first time through */
 	OpExpr	   *op = (OpExpr *) fcache->xprstate.expr;
@@ -2469,7 +2259,7 @@ ExecEvalOper(FuncExprState *fcache,
 
 	/* Change the evalfunc pointer to save a few cycles in additional calls */
 	fcache->xprstate.evalfunc = (ExprStateEvalFunc) ExecMakeFunctionResultNoSets;
-	return ExecMakeFunctionResultNoSets(fcache, econtext, isNull, isDone);
+	return ExecMakeFunctionResultNoSets(fcache, econtext, isNull);
 }
 
 /* ----------------------------------------------------------------
@@ -2486,17 +2276,13 @@ ExecEvalOper(FuncExprState *fcache,
 static Datum
 ExecEvalDistinct(FuncExprState *fcache,
 				 ExprContext *econtext,
-				 bool *isNull,
-				 ExprDoneCond *isDone)
+				 bool *isNull)
 {
 	Datum		result;
 	FunctionCallInfo fcinfo;
-	ExprDoneCond argDone;
 
-	/* Set default values for result flags: non-null, not a set result */
+	/* Set non-null as default */
 	*isNull = false;
-	if (isDone)
-		*isDone = ExprSingleResult;
 
 	/*
 	 * Initialize function cache if first time through
@@ -2513,11 +2299,7 @@ ExecEvalDistinct(FuncExprState *fcache,
 	 * Evaluate arguments
 	 */
 	fcinfo = &fcache->fcinfo_data;
-	argDone = ExecEvalFuncArgs(fcinfo, fcache->args, econtext);
-	if (argDone != ExprSingleResult)
-		ereport(ERROR,
-				(errcode(ERRCODE_DATATYPE_MISMATCH),
-				 errmsg("IS DISTINCT FROM does not support set arguments")));
+	ExecEvalFuncArgs(fcinfo, fcache->args, econtext);
 	Assert(fcinfo->nargs == 2);
 
 	if (fcinfo->argnull[0] && fcinfo->argnull[1])
@@ -2553,7 +2335,7 @@ ExecEvalDistinct(FuncExprState *fcache,
 static Datum
 ExecEvalScalarArrayOp(ScalarArrayOpExprState *sstate,
 					  ExprContext *econtext,
-					  bool *isNull, ExprDoneCond *isDone)
+					  bool *isNull)
 {
 	ScalarArrayOpExpr *opexpr = (ScalarArrayOpExpr *) sstate->fxprstate.xprstate.expr;
 	bool		useOr = opexpr->useOr;
@@ -2562,7 +2344,6 @@ ExecEvalScalarArrayOp(ScalarArrayOpExprState *sstate,
 	Datum		result;
 	bool		resultnull;
 	FunctionCallInfo fcinfo;
-	ExprDoneCond argDone;
 	int			i;
 	int16		typlen;
 	bool		typbyval;
@@ -2571,10 +2352,8 @@ ExecEvalScalarArrayOp(ScalarArrayOpExprState *sstate,
 	bits8	   *bitmap;
 	int			bitmask;
 
-	/* Set default values for result flags: non-null, not a set result */
+	/* Set non-null as default */
 	*isNull = false;
-	if (isDone)
-		*isDone = ExprSingleResult;
 
 	/*
 	 * Initialize function cache if first time through
@@ -2589,11 +2368,7 @@ ExecEvalScalarArrayOp(ScalarArrayOpExprState *sstate,
 	 * Evaluate arguments
 	 */
 	fcinfo = &sstate->fxprstate.fcinfo_data;
-	argDone = ExecEvalFuncArgs(fcinfo, sstate->fxprstate.args, econtext);
-	if (argDone != ExprSingleResult)
-		ereport(ERROR,
-				(errcode(ERRCODE_DATATYPE_MISMATCH),
-			   errmsg("op ANY/ALL (array) does not support set arguments")));
+	ExecEvalFuncArgs(fcinfo, sstate->fxprstate.args, econtext);
 	Assert(fcinfo->nargs == 2);
 
 	/*
@@ -2739,15 +2514,12 @@ ExecEvalScalarArrayOp(ScalarArrayOpExprState *sstate,
  */
 static Datum
 ExecEvalNot(BoolExprState *notclause, ExprContext *econtext,
-			bool *isNull, ExprDoneCond *isDone)
+			bool *isNull)
 {
 	ExprState  *clause = linitial(notclause->args);
 	Datum		expr_value;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
-	expr_value = ExecEvalExpr(clause, econtext, isNull, NULL);
+	expr_value = ExecEvalExpr(clause, econtext, isNull);
 
 	/*
 	 * if the expression evaluates to null, then we just cascade the null back
@@ -2769,15 +2541,12 @@ ExecEvalNot(BoolExprState *notclause, ExprContext *econtext,
  */
 static Datum
 ExecEvalOr(BoolExprState *orExpr, ExprContext *econtext,
-		   bool *isNull, ExprDoneCond *isDone)
+		   bool *isNull)
 {
 	List	   *clauses = orExpr->args;
 	ListCell   *clause;
 	bool		AnyNull;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	AnyNull = false;
 
 	/*
@@ -2798,7 +2567,7 @@ ExecEvalOr(BoolExprState *orExpr, ExprContext *econtext,
 		ExprState  *clausestate = (ExprState *) lfirst(clause);
 		Datum		clause_value;
 
-		clause_value = ExecEvalExpr(clausestate, econtext, isNull, NULL);
+		clause_value = ExecEvalExpr(clausestate, econtext, isNull);
 
 		/*
 		 * if we have a non-null true result, then return it.
@@ -2820,15 +2589,12 @@ ExecEvalOr(BoolExprState *orExpr, ExprContext *econtext,
  */
 static Datum
 ExecEvalAnd(BoolExprState *andExpr, ExprContext *econtext,
-			bool *isNull, ExprDoneCond *isDone)
+			bool *isNull)
 {
 	List	   *clauses = andExpr->args;
 	ListCell   *clause;
 	bool		AnyNull;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	AnyNull = false;
 
 	/*
@@ -2845,7 +2611,7 @@ ExecEvalAnd(BoolExprState *andExpr, ExprContext *econtext,
 		ExprState  *clausestate = (ExprState *) lfirst(clause);
 		Datum		clause_value;
 
-		clause_value = ExecEvalExpr(clausestate, econtext, isNull, NULL);
+		clause_value = ExecEvalExpr(clausestate, econtext, isNull);
 
 		/*
 		 * if we have a non-null false result, then return it.
@@ -2871,7 +2637,7 @@ ExecEvalAnd(BoolExprState *andExpr, ExprContext *econtext,
 static Datum
 ExecEvalConvertRowtype(ConvertRowtypeExprState *cstate,
 					   ExprContext *econtext,
-					   bool *isNull, ExprDoneCond *isDone)
+					   bool *isNull)
 {
 	ConvertRowtypeExpr *convert = (ConvertRowtypeExpr *) cstate->xprstate.expr;
 	HeapTuple	result;
@@ -2879,7 +2645,7 @@ ExecEvalConvertRowtype(ConvertRowtypeExprState *cstate,
 	HeapTupleHeader tuple;
 	HeapTupleData tmptup;
 
-	tupDatum = ExecEvalExpr(cstate->arg, econtext, isNull, isDone);
+	tupDatum = ExecEvalExpr(cstate->arg, econtext, isNull);
 
 	/* this test covers the isDone exception too: */
 	if (*isNull)
@@ -2955,16 +2721,13 @@ ExecEvalConvertRowtype(ConvertRowtypeExprState *cstate,
  */
 static Datum
 ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext,
-			 bool *isNull, ExprDoneCond *isDone)
+			 bool *isNull)
 {
 	List	   *clauses = caseExpr->args;
 	ListCell   *clause;
 	Datum		save_datum;
 	bool		save_isNull;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	/*
 	 * If there's a test expression, we have to evaluate it and save the value
 	 * where the CaseTestExpr placeholders can find it.  We must save and
@@ -2989,8 +2752,7 @@ ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext,
 
 		arg_value = ExecEvalExpr(caseExpr->arg,
 								 econtext,
-								 &arg_isNull,
-								 NULL);
+								 &arg_isNull);
 		/* Since caseValue_datum may be read multiple times, force to R/O */
 		econtext->caseValue_datum =
 			MakeExpandedObjectReadOnly(arg_value,
@@ -3012,8 +2774,7 @@ ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext,
 
 		clause_value = ExecEvalExpr(wclause->expr,
 									econtext,
-									&clause_isNull,
-									NULL);
+									&clause_isNull);
 
 		/*
 		 * if we have a true test, then we return the result, since the case
@@ -3026,8 +2787,7 @@ ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext,
 			econtext->caseValue_isNull = save_isNull;
 			return ExecEvalExpr(wclause->result,
 								econtext,
-								isNull,
-								isDone);
+								isNull);
 		}
 	}
 
@@ -3038,8 +2798,7 @@ ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext,
 	{
 		return ExecEvalExpr(caseExpr->defresult,
 							econtext,
-							isNull,
-							isDone);
+							isNull);
 	}
 
 	*isNull = true;
@@ -3054,10 +2813,8 @@ ExecEvalCase(CaseExprState *caseExpr, ExprContext *econtext,
 static Datum
 ExecEvalCaseTestExpr(ExprState *exprstate,
 					 ExprContext *econtext,
-					 bool *isNull, ExprDoneCond *isDone)
+					 bool *isNull)
 {
-	if (isDone)
-		*isDone = ExprSingleResult;
 	*isNull = econtext->caseValue_isNull;
 	return econtext->caseValue_datum;
 }
@@ -3074,17 +2831,13 @@ ExecEvalCaseTestExpr(ExprState *exprstate,
 static Datum
 ExecEvalGroupingFuncExpr(GroupingFuncExprState *gstate,
 						 ExprContext *econtext,
-						 bool *isNull,
-						 ExprDoneCond *isDone)
+						 bool *isNull)
 {
 	int			result = 0;
 	int			attnum = 0;
 	Bitmapset  *grouped_cols = gstate->aggstate->grouped_cols;
 	ListCell   *lc;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	*isNull = false;
 
 	foreach(lc, (gstate->clauses))
@@ -3106,7 +2859,7 @@ ExecEvalGroupingFuncExpr(GroupingFuncExprState *gstate,
  */
 static Datum
 ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
-			  bool *isNull, ExprDoneCond *isDone)
+			  bool *isNull)
 {
 	ArrayExpr  *arrayExpr = (ArrayExpr *) astate->xprstate.expr;
 	ArrayType  *result;
@@ -3116,10 +2869,8 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
 	int			dims[MAXDIM];
 	int			lbs[MAXDIM];
 
-	/* Set default values for result flags: non-null, not a set result */
+	/* Set non-null as default */
 	*isNull = false;
-	if (isDone)
-		*isDone = ExprSingleResult;
 
 	if (!arrayExpr->multidims)
 	{
@@ -3144,7 +2895,7 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
 		{
 			ExprState  *e = (ExprState *) lfirst(element);
 
-			dvalues[i] = ExecEvalExpr(e, econtext, &dnulls[i], NULL);
+			dvalues[i] = ExecEvalExpr(e, econtext, &dnulls[i]);
 			i++;
 		}
 
@@ -3194,7 +2945,7 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
 			ArrayType  *array;
 			int			this_ndims;
 
-			arraydatum = ExecEvalExpr(e, econtext, &eisnull, NULL);
+			arraydatum = ExecEvalExpr(e, econtext, &eisnull);
 			/* temporarily ignore null subarrays */
 			if (eisnull)
 			{
@@ -3333,7 +3084,7 @@ ExecEvalArray(ArrayExprState *astate, ExprContext *econtext,
 static Datum
 ExecEvalRow(RowExprState *rstate,
 			ExprContext *econtext,
-			bool *isNull, ExprDoneCond *isDone)
+			bool *isNull)
 {
 	HeapTuple	tuple;
 	Datum	   *values;
@@ -3342,10 +3093,8 @@ ExecEvalRow(RowExprState *rstate,
 	ListCell   *arg;
 	int			i;
 
-	/* Set default values for result flags: non-null, not a set result */
+	/* Set non-null as default */
 	*isNull = false;
-	if (isDone)
-		*isDone = ExprSingleResult;
 
 	/* Allocate workspace */
 	natts = rstate->tupdesc->natts;
@@ -3361,7 +3110,7 @@ ExecEvalRow(RowExprState *rstate,
 	{
 		ExprState  *e = (ExprState *) lfirst(arg);
 
-		values[i] = ExecEvalExpr(e, econtext, &isnull[i], NULL);
+		values[i] = ExecEvalExpr(e, econtext, &isnull[i]);
 		i++;
 	}
 
@@ -3380,7 +3129,7 @@ ExecEvalRow(RowExprState *rstate,
 static Datum
 ExecEvalRowCompare(RowCompareExprState *rstate,
 				   ExprContext *econtext,
-				   bool *isNull, ExprDoneCond *isDone)
+				   bool *isNull)
 {
 	bool		result;
 	RowCompareType rctype = ((RowCompareExpr *) rstate->xprstate.expr)->rctype;
@@ -3389,8 +3138,6 @@ ExecEvalRowCompare(RowCompareExprState *rstate,
 	ListCell   *r;
 	int			i;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
 	*isNull = true;				/* until we get a result */
 
 	i = 0;
@@ -3404,9 +3151,9 @@ ExecEvalRowCompare(RowCompareExprState *rstate,
 								 rstate->collations[i],
 								 NULL, NULL);
 		locfcinfo.arg[0] = ExecEvalExpr(le, econtext,
-										&locfcinfo.argnull[0], NULL);
+										&locfcinfo.argnull[0]);
 		locfcinfo.arg[1] = ExecEvalExpr(re, econtext,
-										&locfcinfo.argnull[1], NULL);
+										&locfcinfo.argnull[1]);
 		if (rstate->funcs[i].fn_strict &&
 			(locfcinfo.argnull[0] || locfcinfo.argnull[1]))
 			return (Datum) 0;	/* force NULL result */
@@ -3450,20 +3197,17 @@ ExecEvalRowCompare(RowCompareExprState *rstate,
  */
 static Datum
 ExecEvalCoalesce(CoalesceExprState *coalesceExpr, ExprContext *econtext,
-				 bool *isNull, ExprDoneCond *isDone)
+				 bool *isNull)
 {
 	ListCell   *arg;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	/* Simply loop through until something NOT NULL is found */
 	foreach(arg, coalesceExpr->args)
 	{
 		ExprState  *e = (ExprState *) lfirst(arg);
 		Datum		value;
 
-		value = ExecEvalExpr(e, econtext, isNull, NULL);
+		value = ExecEvalExpr(e, econtext, isNull);
 		if (!*isNull)
 			return value;
 	}
@@ -3479,7 +3223,7 @@ ExecEvalCoalesce(CoalesceExprState *coalesceExpr, ExprContext *econtext,
  */
 static Datum
 ExecEvalMinMax(MinMaxExprState *minmaxExpr, ExprContext *econtext,
-			   bool *isNull, ExprDoneCond *isDone)
+			   bool *isNull)
 {
 	Datum		result = (Datum) 0;
 	MinMaxExpr *minmax = (MinMaxExpr *) minmaxExpr->xprstate.expr;
@@ -3488,8 +3232,6 @@ ExecEvalMinMax(MinMaxExprState *minmaxExpr, ExprContext *econtext,
 	FunctionCallInfoData locfcinfo;
 	ListCell   *arg;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
 	*isNull = true;				/* until we get a result */
 
 	InitFunctionCallInfoData(locfcinfo, &minmaxExpr->cfunc, 2,
@@ -3504,7 +3246,7 @@ ExecEvalMinMax(MinMaxExprState *minmaxExpr, ExprContext *econtext,
 		bool		valueIsNull;
 		int32		cmpresult;
 
-		value = ExecEvalExpr(e, econtext, &valueIsNull, NULL);
+		value = ExecEvalExpr(e, econtext, &valueIsNull);
 		if (valueIsNull)
 			continue;			/* ignore NULL inputs */
 
@@ -3540,14 +3282,12 @@ ExecEvalMinMax(MinMaxExprState *minmaxExpr, ExprContext *econtext,
 static Datum
 ExecEvalSQLValueFunction(ExprState *svfExpr,
 						 ExprContext *econtext,
-						 bool *isNull, ExprDoneCond *isDone)
+						 bool *isNull)
 {
 	Datum		result = (Datum) 0;
 	SQLValueFunction *svf = (SQLValueFunction *) svfExpr->expr;
 	FunctionCallInfoData fcinfo;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
 	*isNull = false;
 
 	/*
@@ -3608,7 +3348,7 @@ ExecEvalSQLValueFunction(ExprState *svfExpr,
  */
 static Datum
 ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
-			bool *isNull, ExprDoneCond *isDone)
+			bool *isNull)
 {
 	XmlExpr    *xexpr = (XmlExpr *) xmlExpr->xprstate.expr;
 	Datum		value;
@@ -3616,8 +3356,6 @@ ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
 	ListCell   *arg;
 	ListCell   *narg;
 
-	if (isDone)
-		*isDone = ExprSingleResult;
 	*isNull = true;				/* until we get a result */
 
 	switch (xexpr->op)
@@ -3630,7 +3368,7 @@ ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
 				{
 					ExprState  *e = (ExprState *) lfirst(arg);
 
-					value = ExecEvalExpr(e, econtext, &isnull, NULL);
+					value = ExecEvalExpr(e, econtext, &isnull);
 					if (!isnull)
 						values = lappend(values, DatumGetPointer(value));
 				}
@@ -3655,7 +3393,7 @@ ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
 					ExprState  *e = (ExprState *) lfirst(arg);
 					char	   *argname = strVal(lfirst(narg));
 
-					value = ExecEvalExpr(e, econtext, &isnull, NULL);
+					value = ExecEvalExpr(e, econtext, &isnull);
 					if (!isnull)
 					{
 						appendStringInfo(&buf, "<%s>%s</%s>",
@@ -3698,13 +3436,13 @@ ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
 				Assert(list_length(xmlExpr->args) == 2);
 
 				e = (ExprState *) linitial(xmlExpr->args);
-				value = ExecEvalExpr(e, econtext, &isnull, NULL);
+				value = ExecEvalExpr(e, econtext, &isnull);
 				if (isnull)
 					return (Datum) 0;
 				data = DatumGetTextP(value);
 
 				e = (ExprState *) lsecond(xmlExpr->args);
-				value = ExecEvalExpr(e, econtext, &isnull, NULL);
+				value = ExecEvalExpr(e, econtext, &isnull);
 				if (isnull)		/* probably can't happen */
 					return (Datum) 0;
 				preserve_whitespace = DatumGetBool(value);
@@ -3728,7 +3466,7 @@ ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
 				if (xmlExpr->args)
 				{
 					e = (ExprState *) linitial(xmlExpr->args);
-					value = ExecEvalExpr(e, econtext, &isnull, NULL);
+					value = ExecEvalExpr(e, econtext, &isnull);
 					if (isnull)
 						arg = NULL;
 					else
@@ -3755,20 +3493,20 @@ ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
 				Assert(list_length(xmlExpr->args) == 3);
 
 				e = (ExprState *) linitial(xmlExpr->args);
-				value = ExecEvalExpr(e, econtext, &isnull, NULL);
+				value = ExecEvalExpr(e, econtext, &isnull);
 				if (isnull)
 					return (Datum) 0;
 				data = DatumGetXmlP(value);
 
 				e = (ExprState *) lsecond(xmlExpr->args);
-				value = ExecEvalExpr(e, econtext, &isnull, NULL);
+				value = ExecEvalExpr(e, econtext, &isnull);
 				if (isnull)
 					version = NULL;
 				else
 					version = DatumGetTextP(value);
 
 				e = (ExprState *) lthird(xmlExpr->args);
-				value = ExecEvalExpr(e, econtext, &isnull, NULL);
+				value = ExecEvalExpr(e, econtext, &isnull);
 				standalone = DatumGetInt32(value);
 
 				*isNull = false;
@@ -3787,7 +3525,7 @@ ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
 				Assert(list_length(xmlExpr->args) == 1);
 
 				e = (ExprState *) linitial(xmlExpr->args);
-				value = ExecEvalExpr(e, econtext, &isnull, NULL);
+				value = ExecEvalExpr(e, econtext, &isnull);
 				if (isnull)
 					return (Datum) 0;
 
@@ -3805,7 +3543,7 @@ ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
 				Assert(list_length(xmlExpr->args) == 1);
 
 				e = (ExprState *) linitial(xmlExpr->args);
-				value = ExecEvalExpr(e, econtext, &isnull, NULL);
+				value = ExecEvalExpr(e, econtext, &isnull);
 				if (isnull)
 					return (Datum) 0;
 				else
@@ -3832,14 +3570,10 @@ ExecEvalXml(XmlExprState *xmlExpr, ExprContext *econtext,
 static Datum
 ExecEvalNullIf(FuncExprState *nullIfExpr,
 			   ExprContext *econtext,
-			   bool *isNull, ExprDoneCond *isDone)
+			   bool *isNull)
 {
 	Datum		result;
 	FunctionCallInfo fcinfo;
-	ExprDoneCond argDone;
-
-	if (isDone)
-		*isDone = ExprSingleResult;
 
 	/*
 	 * Initialize function cache if first time through
@@ -3856,11 +3590,7 @@ ExecEvalNullIf(FuncExprState *nullIfExpr,
 	 * Evaluate arguments
 	 */
 	fcinfo = &nullIfExpr->fcinfo_data;
-	argDone = ExecEvalFuncArgs(fcinfo, nullIfExpr->args, econtext);
-	if (argDone != ExprSingleResult)
-		ereport(ERROR,
-				(errcode(ERRCODE_DATATYPE_MISMATCH),
-				 errmsg("NULLIF does not support set arguments")));
+	ExecEvalFuncArgs(fcinfo, nullIfExpr->args, econtext);
 	Assert(fcinfo->nargs == 2);
 
 	/* if either argument is NULL they can't be equal */
@@ -3890,16 +3620,12 @@ ExecEvalNullIf(FuncExprState *nullIfExpr,
 static Datum
 ExecEvalNullTest(NullTestState *nstate,
 				 ExprContext *econtext,
-				 bool *isNull,
-				 ExprDoneCond *isDone)
+				 bool *isNull)
 {
 	NullTest   *ntest = (NullTest *) nstate->xprstate.expr;
 	Datum		result;
 
-	result = ExecEvalExpr(nstate->arg, econtext, isNull, isDone);
-
-	if (isDone && *isDone == ExprEndResult)
-		return result;			/* nothing to check */
+	result = ExecEvalExpr(nstate->arg, econtext, isNull);
 
 	if (ntest->argisrow && !(*isNull))
 	{
@@ -3999,16 +3725,12 @@ ExecEvalNullTest(NullTestState *nstate,
 static Datum
 ExecEvalBooleanTest(GenericExprState *bstate,
 					ExprContext *econtext,
-					bool *isNull,
-					ExprDoneCond *isDone)
+					bool *isNull)
 {
 	BooleanTest *btest = (BooleanTest *) bstate->xprstate.expr;
 	Datum		result;
 
-	result = ExecEvalExpr(bstate->arg, econtext, isNull, isDone);
-
-	if (isDone && *isDone == ExprEndResult)
-		return result;			/* nothing to check */
+	result = ExecEvalExpr(bstate->arg, econtext, isNull);
 
 	switch (btest->booltesttype)
 	{
@@ -4084,16 +3806,13 @@ ExecEvalBooleanTest(GenericExprState *bstate,
  */
 static Datum
 ExecEvalCoerceToDomain(CoerceToDomainState *cstate, ExprContext *econtext,
-					   bool *isNull, ExprDoneCond *isDone)
+					   bool *isNull)
 {
 	CoerceToDomain *ctest = (CoerceToDomain *) cstate->xprstate.expr;
 	Datum		result;
 	ListCell   *l;
 
-	result = ExecEvalExpr(cstate->arg, econtext, isNull, isDone);
-
-	if (isDone && *isDone == ExprEndResult)
-		return result;			/* nothing to check */
+	result = ExecEvalExpr(cstate->arg, econtext, isNull);
 
 	/* Make sure we have up-to-date constraints */
 	UpdateDomainConstraintRef(cstate->constraint_ref);
@@ -4138,8 +3857,8 @@ ExecEvalCoerceToDomain(CoerceToDomainState *cstate, ExprContext *econtext,
 									 cstate->constraint_ref->tcache->typlen);
 					econtext->domainValue_isNull = *isNull;
 
-					conResult = ExecEvalExpr(con->check_expr,
-											 econtext, &conIsNull, NULL);
+					conResult = ExecEvalExpr(con->check_expr, econtext,
+											 &conIsNull);
 
 					if (!conIsNull &&
 						!DatumGetBool(conResult))
@@ -4174,10 +3893,8 @@ ExecEvalCoerceToDomain(CoerceToDomainState *cstate, ExprContext *econtext,
 static Datum
 ExecEvalCoerceToDomainValue(ExprState *exprstate,
 							ExprContext *econtext,
-							bool *isNull, ExprDoneCond *isDone)
+							bool *isNull)
 {
-	if (isDone)
-		*isDone = ExprSingleResult;
 	*isNull = econtext->domainValue_isNull;
 	return econtext->domainValue_datum;
 }
@@ -4191,8 +3908,7 @@ ExecEvalCoerceToDomainValue(ExprState *exprstate,
 static Datum
 ExecEvalFieldSelect(FieldSelectState *fstate,
 					ExprContext *econtext,
-					bool *isNull,
-					ExprDoneCond *isDone)
+					bool *isNull)
 {
 	FieldSelect *fselect = (FieldSelect *) fstate->xprstate.expr;
 	AttrNumber	fieldnum = fselect->fieldnum;
@@ -4205,9 +3921,8 @@ ExecEvalFieldSelect(FieldSelectState *fstate,
 	Form_pg_attribute attr;
 	HeapTupleData tmptup;
 
-	tupDatum = ExecEvalExpr(fstate->arg, econtext, isNull, isDone);
+	tupDatum = ExecEvalExpr(fstate->arg, econtext, isNull);
 
-	/* this test covers the isDone exception too: */
 	if (*isNull)
 		return tupDatum;
 
@@ -4270,8 +3985,7 @@ ExecEvalFieldSelect(FieldSelectState *fstate,
 static Datum
 ExecEvalFieldStore(FieldStoreState *fstate,
 				   ExprContext *econtext,
-				   bool *isNull,
-				   ExprDoneCond *isDone)
+				   bool *isNull)
 {
 	FieldStore *fstore = (FieldStore *) fstate->xprstate.expr;
 	HeapTuple	tuple;
@@ -4284,10 +3998,7 @@ ExecEvalFieldStore(FieldStoreState *fstate,
 	ListCell   *l1,
 			   *l2;
 
-	tupDatum = ExecEvalExpr(fstate->arg, econtext, isNull, isDone);
-
-	if (isDone && *isDone == ExprEndResult)
-		return tupDatum;
+	tupDatum = ExecEvalExpr(fstate->arg, econtext, isNull);
 
 	/* Lookup tupdesc if first time through or after rescan */
 	tupDesc = get_cached_rowtype(fstore->resulttype, -1,
@@ -4347,8 +4058,7 @@ ExecEvalFieldStore(FieldStoreState *fstate,
 
 		values[fieldnum - 1] = ExecEvalExpr(newval,
 											econtext,
-											&isnull[fieldnum - 1],
-											NULL);
+											&isnull[fieldnum - 1]);
 	}
 
 	econtext->caseValue_datum = save_datum;
@@ -4371,9 +4081,9 @@ ExecEvalFieldStore(FieldStoreState *fstate,
 static Datum
 ExecEvalRelabelType(GenericExprState *exprstate,
 					ExprContext *econtext,
-					bool *isNull, ExprDoneCond *isDone)
+					bool *isNull)
 {
-	return ExecEvalExpr(exprstate->arg, econtext, isNull, isDone);
+	return ExecEvalExpr(exprstate->arg, econtext, isNull);
 }
 
 /* ----------------------------------------------------------------
@@ -4385,16 +4095,13 @@ ExecEvalRelabelType(GenericExprState *exprstate,
 static Datum
 ExecEvalCoerceViaIO(CoerceViaIOState *iostate,
 					ExprContext *econtext,
-					bool *isNull, ExprDoneCond *isDone)
+					bool *isNull)
 {
 	Datum		result;
 	Datum		inputval;
 	char	   *string;
 
-	inputval = ExecEvalExpr(iostate->arg, econtext, isNull, isDone);
-
-	if (isDone && *isDone == ExprEndResult)
-		return inputval;		/* nothing to do */
+	inputval = ExecEvalExpr(iostate->arg, econtext, isNull);
 
 	if (*isNull)
 		string = NULL;			/* output functions are not called on nulls */
@@ -4419,16 +4126,14 @@ ExecEvalCoerceViaIO(CoerceViaIOState *iostate,
 static Datum
 ExecEvalArrayCoerceExpr(ArrayCoerceExprState *astate,
 						ExprContext *econtext,
-						bool *isNull, ExprDoneCond *isDone)
+						bool *isNull)
 {
 	ArrayCoerceExpr *acoerce = (ArrayCoerceExpr *) astate->xprstate.expr;
 	Datum		result;
 	FunctionCallInfoData locfcinfo;
 
-	result = ExecEvalExpr(astate->arg, econtext, isNull, isDone);
+	result = ExecEvalExpr(astate->arg, econtext, isNull);
 
-	if (isDone && *isDone == ExprEndResult)
-		return result;			/* nothing to do */
 	if (*isNull)
 		return result;			/* nothing to do */
 
@@ -4496,7 +4201,7 @@ ExecEvalArrayCoerceExpr(ArrayCoerceExprState *astate,
  */
 static Datum
 ExecEvalCurrentOfExpr(ExprState *exprstate, ExprContext *econtext,
-					  bool *isNull, ExprDoneCond *isDone)
+					  bool *isNull)
 {
 	ereport(ERROR,
 			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
@@ -4513,14 +4218,13 @@ ExecEvalCurrentOfExpr(ExprState *exprstate, ExprContext *econtext,
 Datum
 ExecEvalExprSwitchContext(ExprState *expression,
 						  ExprContext *econtext,
-						  bool *isNull,
-						  ExprDoneCond *isDone)
+						  bool *isNull)
 {
 	Datum		retDatum;
 	MemoryContext oldContext;
 
 	oldContext = MemoryContextSwitchTo(econtext->ecxt_per_tuple_memory);
-	retDatum = ExecEvalExpr(expression, econtext, isNull, isDone);
+	retDatum = ExecEvalExpr(expression, econtext, isNull);
 	MemoryContextSwitchTo(oldContext);
 	return retDatum;
 }
@@ -5387,7 +5091,7 @@ ExecQual(List *qual, ExprContext *econtext, bool resultForNull)
 		Datum		expr_value;
 		bool		isNull;
 
-		expr_value = ExecEvalExpr(clause, econtext, &isNull, NULL);
+		expr_value = ExecEvalExpr(clause, econtext, &isNull);
 
 		if (isNull)
 		{
@@ -5445,17 +5149,11 @@ ExecCleanTargetListLength(List *targetlist)
 /*
  * ExecTargetList
  *		Evaluates a targetlist with respect to the given
- *		expression context.  Returns TRUE if we were able to create
- *		a result, FALSE if we have exhausted a set-valued expression.
+ *		expression context.
  *
- * Results are stored into the passed values and isnull arrays.
- * The caller must provide an itemIsDone array that persists across calls.
+ * tupdesc must describe the rowtype of the expected result.
  *
- * As with ExecEvalExpr, the caller should pass isDone = NULL if not
- * prepared to deal with sets of result tuples.  Otherwise, a return
- * of *isDone = ExprMultipleResult signifies a set element, and a return
- * of *isDone = ExprEndResult signifies end of the set of tuple.
- * We assume that *isDone has been initialized to ExprSingleResult by caller.
+ * Results are stored into the passed values and isnull arrays.
  *
  * Since fields of the result tuple might be multiply referenced in higher
  * plan nodes, we have to force any read/write expanded values to read-only
@@ -5464,19 +5162,16 @@ ExecCleanTargetListLength(List *targetlist)
  * actually-multiply-referenced Vars and insert an expression node that
  * would do that only where really required.
  */
-static bool
+static void
 ExecTargetList(List *targetlist,
 			   TupleDesc tupdesc,
 			   ExprContext *econtext,
 			   Datum *values,
-			   bool *isnull,
-			   ExprDoneCond *itemIsDone,
-			   ExprDoneCond *isDone)
+			   bool *isnull)
 {
 	Form_pg_attribute *att = tupdesc->attrs;
 	MemoryContext oldContext;
 	ListCell   *tl;
-	bool		haveDoneSets;
 
 	/*
 	 * Run in short-lived per-tuple context while computing expressions.
@@ -5486,8 +5181,6 @@ ExecTargetList(List *targetlist,
 	/*
 	 * evaluate all the expressions in the target list
 	 */
-	haveDoneSets = false;		/* any exhausted set exprs in tlist? */
-
 	foreach(tl, targetlist)
 	{
 		GenericExprState *gstate = (GenericExprState *) lfirst(tl);
@@ -5496,117 +5189,14 @@ ExecTargetList(List *targetlist,
 
 		values[resind] = ExecEvalExpr(gstate->arg,
 									  econtext,
-									  &isnull[resind],
-									  &itemIsDone[resind]);
+									  &isnull[resind]);
 
 		values[resind] = MakeExpandedObjectReadOnly(values[resind],
 													isnull[resind],
 													att[resind]->attlen);
-
-		if (itemIsDone[resind] != ExprSingleResult)
-		{
-			/* We have a set-valued expression in the tlist */
-			if (isDone == NULL)
-				ereport(ERROR,
-						(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
-						 errmsg("set-valued function called in context that cannot accept a set")));
-			if (itemIsDone[resind] == ExprMultipleResult)
-			{
-				/* we have undone sets in the tlist, set flag */
-				*isDone = ExprMultipleResult;
-			}
-			else
-			{
-				/* we have done sets in the tlist, set flag for that */
-				haveDoneSets = true;
-			}
-		}
 	}
 
-	if (haveDoneSets)
-	{
-		/*
-		 * note: can't get here unless we verified isDone != NULL
-		 */
-		if (*isDone == ExprSingleResult)
-		{
-			/*
-			 * all sets are done, so report that tlist expansion is complete.
-			 */
-			*isDone = ExprEndResult;
-			MemoryContextSwitchTo(oldContext);
-			return false;
-		}
-		else
-		{
-			/*
-			 * We have some done and some undone sets.  Restart the done ones
-			 * so that we can deliver a tuple (if possible).
-			 */
-			foreach(tl, targetlist)
-			{
-				GenericExprState *gstate = (GenericExprState *) lfirst(tl);
-				TargetEntry *tle = (TargetEntry *) gstate->xprstate.expr;
-				AttrNumber	resind = tle->resno - 1;
-
-				if (itemIsDone[resind] == ExprEndResult)
-				{
-					values[resind] = ExecEvalExpr(gstate->arg,
-												  econtext,
-												  &isnull[resind],
-												  &itemIsDone[resind]);
-
-					values[resind] = MakeExpandedObjectReadOnly(values[resind],
-															  isnull[resind],
-														att[resind]->attlen);
-
-					if (itemIsDone[resind] == ExprEndResult)
-					{
-						/*
-						 * Oh dear, this item is returning an empty set. Guess
-						 * we can't make a tuple after all.
-						 */
-						*isDone = ExprEndResult;
-						break;
-					}
-				}
-			}
-
-			/*
-			 * If we cannot make a tuple because some sets are empty, we still
-			 * have to cycle the nonempty sets to completion, else resources
-			 * will not be released from subplans etc.
-			 *
-			 * XXX is that still necessary?
-			 */
-			if (*isDone == ExprEndResult)
-			{
-				foreach(tl, targetlist)
-				{
-					GenericExprState *gstate = (GenericExprState *) lfirst(tl);
-					TargetEntry *tle = (TargetEntry *) gstate->xprstate.expr;
-					AttrNumber	resind = tle->resno - 1;
-
-					while (itemIsDone[resind] == ExprMultipleResult)
-					{
-						values[resind] = ExecEvalExpr(gstate->arg,
-													  econtext,
-													  &isnull[resind],
-													  &itemIsDone[resind]);
-						/* no need for MakeExpandedObjectReadOnly */
-					}
-				}
-
-				MemoryContextSwitchTo(oldContext);
-				return false;
-			}
-		}
-	}
-
-	/* Report success */
 	MemoryContextSwitchTo(oldContext);
-
-	return true;
 }
 
 /*
@@ -5623,7 +5213,7 @@ ExecTargetList(List *targetlist,
  *		result slot.
  */
 TupleTableSlot *
-ExecProject(ProjectionInfo *projInfo, ExprDoneCond *isDone)
+ExecProject(ProjectionInfo *projInfo)
 {
 	TupleTableSlot *slot;
 	ExprContext *econtext;
@@ -5640,14 +5230,9 @@ ExecProject(ProjectionInfo *projInfo, ExprDoneCond *isDone)
 	slot = projInfo->pi_slot;
 	econtext = projInfo->pi_exprContext;
 
-	/* Assume single result row until proven otherwise */
-	if (isDone)
-		*isDone = ExprSingleResult;
-
 	/*
 	 * Clear any former contents of the result slot.  This makes it safe for
-	 * us to use the slot's Datum/isnull arrays as workspace. (Also, we can
-	 * return the slot as-is if we decide no rows can be projected.)
+	 * us to use the slot's Datum/isnull arrays as workspace.
 	 */
 	ExecClearTuple(slot);
 
@@ -5711,26 +5296,19 @@ ExecProject(ProjectionInfo *projInfo, ExprDoneCond *isDone)
 	}
 
 	/*
-	 * If there are any generic expressions, evaluate them.  It's possible
-	 * that there are set-returning functions in such expressions; if so and
-	 * we have reached the end of the set, we return the result slot, which we
-	 * already marked empty.
+	 * If there are any generic expressions, evaluate them.
 	 */
 	if (projInfo->pi_targetlist)
 	{
-		if (!ExecTargetList(projInfo->pi_targetlist,
-							slot->tts_tupleDescriptor,
-							econtext,
-							slot->tts_values,
-							slot->tts_isnull,
-							projInfo->pi_itemIsDone,
-							isDone))
-			return slot;		/* no more result rows, return empty slot */
+		ExecTargetList(projInfo->pi_targetlist,
+					   slot->tts_tupleDescriptor,
+					   econtext,
+					   slot->tts_values,
+					   slot->tts_isnull);
 	}
 
 	/*
-	 * Successfully formed a result row.  Mark the result slot as containing a
-	 * valid virtual tuple.
+	 * Mark the result slot as containing a valid virtual tuple.
 	 */
 	return ExecStoreVirtualTuple(slot);
 }