internal/core/adt: fix initArcs for errors in optional fields

An error in an optional field is okay. Yet, initArcs, which
pre-initialized the arcs of the previously existing structure,
would consider it to be erroneous.
This would result in disjunction processing to be skipped.
However, there was no actual error.
This, in turn, would cause typo checking to be triggered,
which result in missing fields, as some of the "evidence"
for allowing a field was now missing.

Fixes #4022

Signed-off-by: Marcel van Lohuizen <[email protected]>
Change-Id: I6f6c21f7eab1fa8117e27bd143f5eb32f00248b5
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1220129
Unity-Result: CUE porcuepine <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>
Reviewed-by: Daniel Martí <[email protected]>
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1220255

Author: mpvl

cue/testdata/disjunctions/errors.txtar

@@ -166,14 +166,6 @@ MisalignedConjunct: 1
 NumCloseIDs: 11
 -- out/evalalpha --
 Errors:
-issue4022.full.out.apiVersion: field not allowed:
-    ./optionalerror.cue:24:3
-issue4022.full.out.metadata: field not allowed:
-    ./optionalerror.cue:10:3
-    ./optionalerror.cue:23:3
-issue4022.reduced.out.metadata: field not allowed:
-    ./optionalerror.cue:2:18
-    ./optionalerror.cue:6:7
 issue516.x: 2 errors in empty disjunction:
 issue516.x.match: field not allowed:
     ./in.cue:23:5
@@ -379,10 +371,8 @@ Result:
         }
       }) }
   }
-  issue4022: (_|_){
-    // [eval]
-    reduced: (_|_){
-      // [eval]
+  issue4022: (struct){
+    reduced: (struct){
       #NonNamespaced: (#struct){
         metadata: (#struct){
           namespace?: (_|_){
@@ -399,21 +389,16 @@ Result:
             }
           }
         }) }
-      out: (_|_){
-        // [eval]
-        metadata: (_|_){
-          // [eval] issue4022.reduced.out.metadata: field not allowed:
-          //     ./optionalerror.cue:2:18
-          //     ./optionalerror.cue:6:7
+      out: (#struct){
+        metadata: (#struct){
           namespace?: (_|_){
             // [user] explicit error (_|_ literal) in source:
             //     ./optionalerror.cue:2:40
           }
         }
       }
     }
-    full: (_|_){
-      // [eval]
+    full: (struct){
       #NonNamespaced: (#struct){
         metadata: (#struct){
           name!: (string){ string }
@@ -432,22 +417,15 @@ Result:
             }
           }
         }) }
-      out: (_|_){
-        // [eval]
-        metadata: (_|_){
-          // [eval] issue4022.full.out.metadata: field not allowed:
-          //     ./optionalerror.cue:10:3
-          //     ./optionalerror.cue:23:3
+      out: (#struct){
+        metadata: (#struct){
           name: (string){ "foo" }
           namespace?: (_|_){
             // [user] explicit error (_|_ literal) in source:
             //     ./optionalerror.cue:12:16
           }
         }
-        apiVersion: (_|_){
-          // [eval] issue4022.full.out.apiVersion: field not allowed:
-          //     ./optionalerror.cue:24:3
-        }
+        apiVersion: (string){ "v1" }
       }
     }
   }
@@ -456,16 +434,8 @@ Result:
 diff old new
 --- old
 +++ new
-@@ -1,15 +1,18 @@
+@@ -1,15 +1,10 @@
  Errors:
-+issue4022.full.out.apiVersion: field not allowed:
-+    ./optionalerror.cue:24:3
-+issue4022.full.out.metadata: field not allowed:
-+    ./optionalerror.cue:10:3
-+    ./optionalerror.cue:23:3
-+issue4022.reduced.out.metadata: field not allowed:
-+    ./optionalerror.cue:2:18
-+    ./optionalerror.cue:6:7
  issue516.x: 2 errors in empty disjunction:
  issue516.x.match: field not allowed:
 -    ./in.cue:20:6
@@ -480,7 +450,7 @@ diff old new
      ./in.cue:3:19
      ./in.cue:12:12
 
-@@ -19,17 +22,12 @@
+@@ -19,17 +14,12 @@
    issue570: (_|_){
      // [eval]
      results: (_|_){
@@ -499,7 +469,7 @@ diff old new
      }
      #Output: (#struct){ |((#struct){
          result: (_){ _ }
-@@ -40,7 +38,9 @@
+@@ -40,7 +30,9 @@
          result: (list){
          }
        }, (#struct){
@@ -510,7 +480,7 @@ diff old new
          }
          error: (string){ string }
        }) }
-@@ -59,18 +59,10 @@
+@@ -59,18 +51,10 @@
      x: (_|_){
        // [eval] issue516.x: 2 errors in empty disjunction:
        // issue516.x.match: field not allowed:
@@ -530,7 +500,7 @@ diff old new
          metrics: (struct){
            foo: (struct){
            }
-@@ -136,13 +128,11 @@
+@@ -136,13 +120,11 @@
      reduced: (struct){
        list: (_|_){
          // [incomplete] issue3581.reduced.list: 2 errors in empty disjunction:
@@ -547,116 +517,46 @@ diff old new
        }
        c: (_){ _ }
      }
-@@ -186,7 +176,6 @@
+@@ -186,7 +168,6 @@
        p1: (struct){ |((struct){
            a?: (_|_){
              // [eval] issue3599.reduced.p1.a: conflicting values 2 and 1:
 -            //     ./issue3599.cue:32:2
              //     ./issue3599.cue:32:9
              //     ./issue3599.cue:32:11
            }
-@@ -194,7 +183,6 @@
+@@ -194,7 +175,6 @@
            a: (string){ string }
            b?: (_|_){
              // [eval] issue3599.reduced.p1.b: conflicting values 2 and 1:
 -            //     ./issue3599.cue:32:2
              //     ./issue3599.cue:32:35
              //     ./issue3599.cue:32:37
            }
-@@ -202,7 +190,6 @@
+@@ -202,7 +182,6 @@
        p2: (struct){ |((struct){
            a?: (_|_){
              // [eval] issue3599.reduced.p2.a: conflicting values 2 and 1:
 -            //     ./issue3599.cue:37:2
              //     ./issue3599.cue:37:9
              //     ./issue3599.cue:37:11
            }
-@@ -210,7 +197,6 @@
+@@ -210,7 +189,6 @@
            a: (string){ string }
            b?: (_|_){
              // [eval] issue3599.reduced.p2.b: conflicting values 2 and 1:
 -            //     ./issue3599.cue:37:2
              //     ./issue3599.cue:37:35
              //     ./issue3599.cue:37:37
            }
-@@ -221,14 +207,15 @@
+@@ -221,7 +199,6 @@
          a: (int){ 1 }
          let B#1 = (_|_){
            // [eval] issue3599.let.B: conflicting values 2 and 1:
 -          //     ./issue3599.cue:40:2
            //     ./issue3599.cue:40:29
            //     ./issue3599.cue:40:31
          }
-       }) }
-   }
--  issue4022: (struct){
--    reduced: (struct){
-+  issue4022: (_|_){
-+    // [eval]
-+    reduced: (_|_){
-+      // [eval]
-       #NonNamespaced: (#struct){
-         metadata: (#struct){
-           namespace?: (_|_){
-@@ -245,16 +232,21 @@
-             }
-           }
-         }) }
--      out: (#struct){
--        metadata: (#struct){
--          namespace?: (_|_){
--            // [user] explicit error (_|_ literal) in source:
--            //     ./optionalerror.cue:2:40
--          }
--        }
--      }
--    }
--    full: (struct){
-+      out: (_|_){
-+        // [eval]
-+        metadata: (_|_){
-+          // [eval] issue4022.reduced.out.metadata: field not allowed:
-+          //     ./optionalerror.cue:2:18
-+          //     ./optionalerror.cue:6:7
-+          namespace?: (_|_){
-+            // [user] explicit error (_|_ literal) in source:
-+            //     ./optionalerror.cue:2:40
-+          }
-+        }
-+      }
-+    }
-+    full: (_|_){
-+      // [eval]
-       #NonNamespaced: (#struct){
-         metadata: (#struct){
-           name!: (string){ string }
-@@ -273,8 +265,12 @@
-             }
-           }
-         }) }
--      out: (#struct){
--        metadata: (#struct){
-+      out: (_|_){
-+        // [eval]
-+        metadata: (_|_){
-+          // [eval] issue4022.full.out.metadata: field not allowed:
-+          //     ./optionalerror.cue:10:3
-+          //     ./optionalerror.cue:23:3
-           name: (string){ "foo" }
-           namespace?: (_|_){
-             // [user] explicit error (_|_ literal) in source:
-@@ -281,7 +277,10 @@
-             //     ./optionalerror.cue:12:16
-           }
-         }
--        apiVersion: (string){ "v1" }
-+        apiVersion: (_|_){
-+          // [eval] issue4022.full.out.apiVersion: field not allowed:
-+          //     ./optionalerror.cue:24:3
-+        }
-       }
-     }
-   }
 -- diff/todo/p3 --
 Missing error positions.
 -- diff/explanation --

internal/core/adt/disjunct2.go

@@ -216,19 +216,17 @@ func (n *nodeContext) scheduleDisjunction(d envDisjunct) {
 }
 
 func initArcs(ctx *OpContext, v *Vertex) bool {
-	ok := true
 	for _, a := range v.Arcs {
 		s := a.getState(ctx)
 		if s != nil && s.errs != nil {
-			ok = false
 			if a.ArcType == ArcMember {
-				break
+				return false
 			}
 		} else if !initArcs(ctx, a) {
-			ok = false
+			return false
 		}
 	}
-	return ok
+	return true
 }
 
 func (n *nodeContext) processDisjunctions() *Bottom {