encoding/openapi: fix generation bug in CRD path

This could lead to duplicate path elements.

Tested in new evaluator code.

Change-Id: I0875d135c483bcab772d8fe656f41ed88a57cb20
Reviewed-on: https://cue-review.googlesource.com/c/cue/+/6584
Reviewed-by: CUE cueckoo <cueckoo@gmail.com>
Reviewed-by: Marcel van Lohuizen <mpvl@golang.org>

encoding/openapi/build.go

@@ -211,8 +211,8 @@ func (b *builder) schema(core *builder, name string, v cue.Value) *ast.StructLit
 	var c *builder
 	if core == nil && b.ctx.structural {
 		c = newCoreBuilder(b.ctx)
-		c.buildCore(v)     // initialize core structure
-		c.coreSchema(name) // build the
+		c.buildCore(v) // initialize core structure
+		c.coreSchema()
 	} else {
 		c = newRootBuilder(b.ctx)
 		c.core = core

encoding/openapi/crd.go

@@ -55,25 +55,29 @@ func newCoreBuilder(c *buildContext) *builder {
 	return b
 }
 
-// coreSchema creates the core part of a structural OpenAPI.
-func (b *builder) coreSchema(name string) *ast.StructLit {
+func (b *builder) coreSchemaWithName(name string) *ast.StructLit {
 	oldPath := b.ctx.path
 	b.ctx.path = append(b.ctx.path, name)
-	defer func() { b.ctx.path = oldPath }()
+	s := b.coreSchema()
+	b.ctx.path = oldPath
+	return s
+}
 
+// coreSchema creates the core part of a structural OpenAPI.
+func (b *builder) coreSchema() *ast.StructLit {
 	switch b.kind {
 	case cue.ListKind:
 		if b.items != nil {
 			b.setType("array", "")
-			schema := b.items.coreSchema("*")
+			schema := b.items.coreSchemaWithName("*")
 			b.setSingle("items", schema, false)
 		}
 
 	case cue.StructKind:
 		p := &OrderedMap{}
 		for _, k := range b.keys {
 			sub := b.properties[k]
-			p.Set(k, sub.coreSchema(k))
+			p.Set(k, sub.coreSchemaWithName(k))
 		}
 		if p.len() > 0 || b.items != nil {
 			b.setType("object", "")
@@ -83,7 +87,7 @@ func (b *builder) coreSchema(name string) *ast.StructLit {
 		}
 		// TODO: in Structural schema only one of these is allowed.
 		if b.items != nil {
-			schema := b.items.coreSchema("*")
+			schema := b.items.coreSchemaWithName("*")
 			b.setSingle("additionalProperties", schema, false)
 		}
 	}