cue: do not unify "accept" schema with result in UnifyAccept

EvalV2 used the accept schema solely for validation,
while EvalV3 would unify the accept schema with the
result. This would cause more conjuncts to be unified
with the schema, which caused some tools using the
API to report more conjuncts.

EvalV3 is now more in line with EvalV2.

This fixes most of Issue 3847, but there is an
unrelated issue that affects it that we will
address in a separate CL.

Issue #3847

Signed-off-by: Marcel van Lohuizen <[email protected]>
Change-Id: I918b6b7fa84e862378f19a69a509e009c6028231
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1212214
Reviewed-by: Matthew Sackman <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

Author: mpvl

cue/types.go

@@ -1766,24 +1766,20 @@ func (v Value) UnifyAccept(w Value, accept Value) Value {
 		n.AddConjunct(cv)
 		n.AddConjunct(cw)
 
-		n.Finalize(ctx)
-
-		n.Parent = v.v.Parent
-		n.Label = v.v.Label
-
-		if err := n.Err(ctx); err != nil {
-			return makeValue(v.idx, n, v.parent_)
-		}
-		if err := allowed(ctx, accept.v, n); err != nil {
-			return newErrValue(accept, err)
-		}
-
 	case internal.EvalV3:
 		n.AddOpenConjunct(ctx, v.v)
 		n.AddOpenConjunct(ctx, w.v)
-		ca := adt.MakeRootConjunct(nil, accept.v)
-		n.AddConjunct(ca)
-		n.Finalize(ctx)
+	}
+	n.Finalize(ctx)
+
+	n.Parent = v.v.Parent
+	n.Label = v.v.Label
+
+	if err := n.Err(ctx); err != nil {
+		return makeValue(v.idx, n, v.parent_)
+	}
+	if err := allowed(ctx, accept.v, n); err != nil {
+		return newErrValue(accept, err)
 	}
 
 	return makeValue(v.idx, n, v.parent_)

cue/types_test.go

@@ -2409,8 +2409,9 @@ func TestUnifyAccept(t *testing.T) {
 // Issue #3829
 func TestConjunctDedup(t *testing.T) {
 	type testCase struct {
-		value string
-		want  string
+		value     string
+		want      string
+		conjuncts string // only tested if not ""
 	}
 	testCases := []testCase{{
 		value: `
@@ -2423,6 +2424,16 @@ func TestConjunctDedup(t *testing.T) {
 	f1: int
 	f:  string
 }`,
+	}, {
+		// Issue #3847
+		value: `
+		import "struct"
+
+		#t: struct.MinFields(4)
+		#t: struct.MaxFields(9)
+		`,
+		want:      `struct.MinFields(4) & struct.MaxFields(9)`,
+		conjuncts: `[struct.MinFields(4) struct.MaxFields(9)]`,
 	}}
 
 	matrix := cuetdtest.FullMatrix
@@ -2446,6 +2457,12 @@ func TestConjunctDedup(t *testing.T) {
 				}
 			}
 			t.Equal(fmt.Sprint(v), tc.want)
+
+			_, args = v.Expr()
+			if tc.conjuncts == "" {
+				return
+			}
+			t.Equal(fmt.Sprint(args), tc.conjuncts)
 		})
 	})
 }

encoding/openapi/testdata/embed.txtar

@@ -1,5 +1,3 @@
-#skip-v3
-#skip-v3-noshare
 -- in.cue --
 #Foo: string
 

encoding/openapi/testdata/struct.txtar

@@ -1,4 +1,4 @@
-#skip-v3-noshare
+#skip-v3
 -- in.cue --
 import "struct"