Handle empty right iterators in exists iterator as an EOF

enginetest/queries/script_queries.go

@@ -14657,6 +14657,21 @@ select * from t1 except (
 			},
 		},
 	},
+	{
+		// https://github.com/dolthub/dolt/issues/10258
+		Name: "WHERE NOT EXISTS from empty view",
+		SetUpScript: []string{
+			"CREATE TABLE t1(c0 boolean, c1 boolean);",
+			"insert into t1(c0) values (true), (false)",
+			"create view v0(c0) as select true having false",
+		},
+		Assertions: []ScriptTestAssertion{
+			{
+				Query:    "SELECT * from t1 where not exists (select 1 from v0 where (case t1.c1 when false then v0.c0 else t1.c0 end)) order by c0",
+				Expected: []sql.Row{{0, nil}, {1, nil}},
+			},
+		},
+	},
 	{
 		// https://github.com/dolthub/dolt/issues/10246
 		Dialect: "mysql",

sql/rowexec/join_iters.go

@@ -247,7 +247,6 @@ func newExistsIter(ctx *sql.Context, b sql.NodeExecBuilder, j *plan.JoinNode, ro
 		cond:              j.Filter,
 		scopeLen:          j.ScopeLen,
 		rowSize:           rowSize,
-		nullRej:           j.Filter != nil && plan.IsNullRejecting(j.Filter),
 	}, nil
 }
 
@@ -262,7 +261,6 @@ type existsIter struct {
 	scopeLen          int
 	rowSize           int
 	typ               plan.JoinType
-	nullRej           bool
 	rightIterNonEmpty bool
 }
 
@@ -303,22 +301,7 @@ func (i *existsIter) Next(ctx *sql.Context) (sql.Row, error) {
 				return nil, err
 			}
 			if plan.IsEmptyIter(rIter) {
-				switch {
-				case i.typ.IsSemi():
-					// EXISTS with empty right is always false → skip this left row
-					nextState = esIncLeft
-				case i.typ.IsAnti():
-					if i.nullRej {
-						// Filter is null-rejecting: need to run condition once with nil right so NULL can propagate
-						// and row may be excluded
-						nextState = esCompare
-					} else {
-						// Filter is not null-rejecting: no matches possible, row passes
-						nextState = esRet
-					}
-				default:
-					nextState = esCompare
-				}
+				nextState = esRightIterEOF
 			} else {
 				nextState = esIncRight
 			}