internal/core/adt: check for nil state in parent disjunction

Currently, as nodeContext values are never
reclaimed, the value will always be non-nil.
In certain cases with API usage, though, a
node may have a parent Vertex that is
finalized and whose state field has already
been cleared.

We add. a test to expose this. Without the
added check, the test would fail with the
upcoming memory management
implementation.

Issue #3334

Signed-off-by: Marcel van Lohuizen <[email protected]>
Change-Id: Ibaae384409263fe7aa0ee01a96f49b9000daa387
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1218219
Unity-Result: CUE porcuepine <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>
Reviewed-by: Daniel Martí <[email protected]>

Author: mpvl

internal/core/adt/api_test.go

@@ -0,0 +1,73 @@
+// Copyright 2025 CUE Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package adt_test
+
+import (
+	"testing"
+
+	"cuelang.org/go/cue"
+	"cuelang.org/go/cue/cuecontext"
+)
+
+func closeAll(v cue.Value) cue.Value {
+	path := cue.MakePath(cue.Def("#x"))
+	return v.Context().CompileString("#x: _").FillPath(path, v).LookupPath(path)
+}
+
+type editConfig struct {
+	Edits []cue.Value `json:"edits,omitempty"`
+}
+
+// Modifying values can cause a mix of non-finalized nodes as children of
+// a finalized parent. Ensure that this does not cause issues.
+func TestAPIModifyingValues(t *testing.T) {
+	ctx := cuecontext.New(cuecontext.CUE_DEBUG("logeval=1"))
+
+	v := ctx.CompileString(`
+        edits: [{
+            type: "replace"
+            data!: "^wrong"
+        }]
+    `)
+	if err := v.Err(); err != nil {
+		t.Fatal(err)
+	}
+	closed := closeAll(ctx.EncodeType(editConfig{}))
+
+	v = v.Unify(closed)
+	if err := v.Err(); err != nil {
+		t.Fatal(err)
+	}
+
+	var cfg editConfig
+	if err := v.Decode(&cfg); err != nil {
+		t.Fatal(err)
+	}
+
+	w := ctx.CompileString(`
+        type!: "fill" | "replace"
+        data!: _
+    `)
+
+	if err := w.Err(); err != nil {
+		t.Fatal(err)
+	}
+	x := cfg.Edits[0]
+	x = x.Unify(w)
+
+	if err := x.Err(); err != nil {
+		t.Fatal(err)
+	}
+}

internal/core/adt/disjunct2.go

@@ -267,7 +267,11 @@ func (n *nodeContext) processDisjunctions() *Bottom {
 	var outerRunMode runMode
 	for p := n.node; p != nil; p = p.Parent {
 		if p.IsDisjunct {
-			outerRunMode = p.state.runMode
+			if p.state == nil {
+				outerRunMode = finalize
+			} else {
+				outerRunMode = p.state.runMode
+			}
 			break
 		}
 	}