Revert 9246af6799 because

I miss too much. Patch is returned to commitfest process.

src/backend/executor/execQual.c

@@ -268,12 +268,10 @@ ExecEvalArrayRef(ArrayRefExprState *astate,
 	bool		eisnull;
 	ListCell   *l;
 	int			i = 0,
-				j = 0,
-				indexexpr;
+				j = 0;
 	IntArray	upper,
 				lower;
 	int		   *lIndex;
-	AnyArrayType *arrays;
 
 	array_source = ExecEvalExpr(astate->refexpr,
 								econtext,
@@ -295,7 +293,6 @@ ExecEvalArrayRef(ArrayRefExprState *astate,
 	foreach(l, astate->refupperindexpr)
 	{
 		ExprState  *eltstate = (ExprState *) lfirst(l);
-		eisnull = false;
 
 		if (i >= MAXDIM)
 			ereport(ERROR,
@@ -303,23 +300,10 @@ ExecEvalArrayRef(ArrayRefExprState *astate,
 					 errmsg("number of array dimensions (%d) exceeds the maximum allowed (%d)",
 							i + 1, MAXDIM)));
 
-		if (eltstate == NULL && astate->refattrlength <= 0)
-		{
-			if (isAssignment)
-				ereport(ERROR,
-					(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
-					 errmsg("cannot determine upper index for empty array")));
-			arrays = (AnyArrayType *)DatumGetArrayTypeP(array_source);
-			indexexpr = AARR_LBOUND(arrays)[i] + AARR_DIMS(arrays)[i] - 1;
-		}
-		else
-			indexexpr = DatumGetInt32(ExecEvalExpr(eltstate,
-												   econtext,
-												   &eisnull,
-												   NULL));
-
-		upper.indx[i++] = indexexpr;
-
+		upper.indx[i++] = DatumGetInt32(ExecEvalExpr(eltstate,
+													 econtext,
+													 &eisnull,
+													 NULL));
 		/* If any index expr yields NULL, result is NULL or error */
 		if (eisnull)
 		{
@@ -337,7 +321,6 @@ ExecEvalArrayRef(ArrayRefExprState *astate,
 		foreach(l, astate->reflowerindexpr)
 		{
 			ExprState  *eltstate = (ExprState *) lfirst(l);
-			eisnull = false;
 
 			if (j >= MAXDIM)
 				ereport(ERROR,
@@ -345,19 +328,10 @@ ExecEvalArrayRef(ArrayRefExprState *astate,
 						 errmsg("number of array dimensions (%d) exceeds the maximum allowed (%d)",
 								j + 1, MAXDIM)));
 
-			if (eltstate == NULL)
-			{
-				arrays = (AnyArrayType *)DatumGetArrayTypeP(array_source);
-				indexexpr = AARR_LBOUND(arrays)[j];
-			}
-			else
-				indexexpr = DatumGetInt32(ExecEvalExpr(eltstate,
-													   econtext,
-													   &eisnull,
-													   NULL));
-
-			lower.indx[j++] = indexexpr;
-
+			lower.indx[j++] = DatumGetInt32(ExecEvalExpr(eltstate,
+														 econtext,
+														 &eisnull,
+														 NULL));
 			/* If any index expr yields NULL, result is NULL or error */
 			if (eisnull)
 			{

src/backend/nodes/copyfuncs.c

@@ -2403,8 +2403,6 @@ _copyAIndices(const A_Indices *from)
 
 	COPY_NODE_FIELD(lidx);
 	COPY_NODE_FIELD(uidx);
-	COPY_SCALAR_FIELD(lidx_default);
-	COPY_SCALAR_FIELD(uidx_default);
 
 	return newnode;
 }

src/backend/nodes/equalfuncs.c

@@ -2153,8 +2153,6 @@ _equalAIndices(const A_Indices *a, const A_Indices *b)
 {
 	COMPARE_NODE_FIELD(lidx);
 	COMPARE_NODE_FIELD(uidx);
-	COMPARE_SCALAR_FIELD(lidx_default);
-	COMPARE_SCALAR_FIELD(uidx_default);
 
 	return true;
 }

src/backend/nodes/outfuncs.c

@@ -2765,8 +2765,6 @@ _outA_Indices(StringInfo str, const A_Indices *node)
 
 	WRITE_NODE_FIELD(lidx);
 	WRITE_NODE_FIELD(uidx);
-	WRITE_BOOL_FIELD(lidx_default);
-	WRITE_BOOL_FIELD(uidx_default);
 }
 
 static void

src/backend/parser/gram.y

@@ -13193,35 +13193,6 @@ indirection_el:
 					A_Indices *ai = makeNode(A_Indices);
 					ai->lidx = NULL;
 					ai->uidx = $2;
-					ai->lidx_default = false;
-					ai->uidx_default = false;
-					$$ = (Node *) ai;
-				}
-			| '[' ':' ']'
-				{
-					A_Indices *ai = makeNode(A_Indices);
-					ai->lidx = NULL;
-					ai->uidx = NULL;
-					ai->lidx_default = true;
-					ai->uidx_default = true;
-					$$ = (Node *) ai;
-				}
-			| '[' ':' a_expr ']'
-				{
-					A_Indices *ai = makeNode(A_Indices);
-					ai->lidx = NULL;
-					ai->uidx = $3;
-					ai->lidx_default = true;
-					ai->uidx_default = false;
-					$$ = (Node *) ai;
-				}
-			| '[' a_expr ':' ']'
-				{
-					A_Indices *ai = makeNode(A_Indices);
-					ai->lidx = $2;
-					ai->uidx = NULL;
-					ai->lidx_default = false;
-					ai->uidx_default = true;
 					$$ = (Node *) ai;
 				}
 			| '[' a_expr ':' a_expr ']'
@@ -13229,8 +13200,6 @@ indirection_el:
 					A_Indices *ai = makeNode(A_Indices);
 					ai->lidx = $2;
 					ai->uidx = $4;
-					ai->lidx_default = false;
-					ai->uidx_default = false;
 					$$ = (Node *) ai;
 				}
 		;

src/backend/parser/parse_node.c

@@ -311,7 +311,7 @@ transformArraySubscripts(ParseState *pstate,
 		elementType = transformArrayType(&arrayType, &arrayTypMod);
 
 	/*
-	 * A list containing only single subscripts (uidx) refers to a single array
+	 * A list containing only single subscripts refers to a single array
 	 * element.  If any of the items are double subscripts (lower:upper), then
 	 * the subscript expression means an array slice operation. In this case,
 	 * we supply a default lower bound of 1 for any items that contain only a
@@ -322,7 +322,7 @@ transformArraySubscripts(ParseState *pstate,
 	{
 		A_Indices  *ai = (A_Indices *) lfirst(idx);
 
-		if (ai->lidx != NULL || ai->lidx_default)
+		if (ai->lidx != NULL)
 		{
 			isSlice = true;
 			break;
@@ -335,17 +335,9 @@ transformArraySubscripts(ParseState *pstate,
 	foreach(idx, indirection)
 	{
 		A_Indices  *ai = (A_Indices *) lfirst(idx);
-		Node	   *subexpr = NULL;
+		Node	   *subexpr;
 
 		Assert(IsA(ai, A_Indices));
-		if ((ai->uidx_default || ai->lidx_default) && assignFrom != NULL)
-			ereport(ERROR,
-					(errcode(ERRCODE_ARRAY_SUBSCRIPT_ERROR),
-					 errmsg("array subscript must have both boundaries"),
-					 errhint("You can't omit the upper or lower"
-							 " boundaries when updating or inserting"),
-					 parser_errposition(pstate, exprLocation(arrayBase))));
-
 		if (isSlice)
 		{
 			if (ai->lidx)
@@ -364,7 +356,7 @@ transformArraySubscripts(ParseState *pstate,
 							 errmsg("array subscript must have type integer"),
 						parser_errposition(pstate, exprLocation(ai->lidx))));
 			}
-			else if (ai->lidx_default == false)
+			else
 			{
 				/* Make a constant 1 */
 				subexpr = (Node *) makeConst(INT4OID,
@@ -377,26 +369,19 @@ transformArraySubscripts(ParseState *pstate,
 			}
 			lowerIndexpr = lappend(lowerIndexpr, subexpr);
 		}
-
-		if (ai->uidx_default == false)
-		{
-			subexpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
-			/* If it's not int4 already, try to coerce */
-			subexpr = coerce_to_target_type(pstate,
-											subexpr, exprType(subexpr),
-											INT4OID, -1,
-											COERCION_ASSIGNMENT,
-											COERCE_IMPLICIT_CAST,
-											-1);
-			if (subexpr == NULL)
-				ereport(ERROR,
-						(errcode(ERRCODE_DATATYPE_MISMATCH),
-						 errmsg("array subscript must have type integer"),
-						 parser_errposition(pstate, exprLocation(ai->uidx))));
-		}
-		else
-			subexpr = NULL;
-
+		subexpr = transformExpr(pstate, ai->uidx, pstate->p_expr_kind);
+		/* If it's not int4 already, try to coerce */
+		subexpr = coerce_to_target_type(pstate,
+										subexpr, exprType(subexpr),
+										INT4OID, -1,
+										COERCION_ASSIGNMENT,
+										COERCE_IMPLICIT_CAST,
+										-1);
+		if (subexpr == NULL)
+			ereport(ERROR,
+					(errcode(ERRCODE_DATATYPE_MISMATCH),
+					 errmsg("array subscript must have type integer"),
+					 parser_errposition(pstate, exprLocation(ai->uidx))));
 		upperIndexpr = lappend(upperIndexpr, subexpr);
 	}
 

src/backend/parser/parse_target.c

@@ -650,7 +650,7 @@ transformAssignmentIndirection(ParseState *pstate,
 		if (IsA(n, A_Indices))
 		{
 			subscripts = lappend(subscripts, n);
-			if (((A_Indices *) n)->lidx != NULL || ((A_Indices *) n)->lidx_default)
+			if (((A_Indices *) n)->lidx != NULL)
 				isSlice = true;
 		}
 		else if (IsA(n, A_Star))