internal/core/adt: force finalizing of shared values

When finalizing a value, CUE currently only finalized
direct arcs and skipped shared values. The reasoning
there is that CUE will anyway evaluated these shared
values eventually as the stack unwinds, meaning that
at the end of a CUE evaluation, all these shared values
are evaluated anyway.

However, this logic does not hold for builtins: if a
value is passed to a builtin mid evaluation, a shared
value may still be unprocessed. Basically, because
evaluation has not finished yet, there is no guarantee
that shared values are finalized.

We now ensure that all shared values comply to the
same requirements as those for the current node
under evaluation.

This fixes the tests added for 3648, but also removes
some discrepancies between V2 and V3.

In one case in particular, constraints.txtar:brokenRing,
this CL reverses a fix and now makes V3 mimic the
same bug as V2. We will accept this regression as
not particularly harmful and the net result is
certainly positive.

Fixes #3648

Signed-off-by: Marcel van Lohuizen <[email protected]>
Change-Id: Ie877e7d94107841e0d9cbcf8b6ecdbcfcde5676b
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1207912
Reviewed-by: Matthew Sackman <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>

Author: mpvl

cue/testdata/cycle/comprehension.txtar

@@ -310,10 +310,10 @@ issue2367: {
 }
 
 -- out/evalalpha/stats --
-Leaks:  782
-Freed:  63
-Reused: 63
-Allocs: 782
+Leaks:  777
+Freed:  68
+Reused: 68
+Allocs: 777
 Retain: 0
 
 Unifications: 502
@@ -583,17 +583,13 @@ Result:
               reject: (string){ string }
             }, (#struct){
               resource: (string){ string }
-            }, (#struct){
-              retry: ~(issue1881.p1.#AllOutputs.retry)
             }) }
         }
       }
       #Output: (#struct){ |((#struct){
           reject: (string){ string }
         }, (#struct){
           resource: (string){ string }
-        }, (#struct){
-          retry: ~(issue1881.p1.#AllOutputs.retry)
         }) }
     }
     p2: (struct){
@@ -790,60 +786,16 @@ diff old new
        }
      }
      acrossOr: (struct){
-@@ -254,27 +247,31 @@
+@@ -254,7 +247,7 @@
    issue1881: (struct){
      p1: (struct){
        o: (#struct){
 -        retry: (#struct){
--          output: (#struct){
--            reject: (string){ "ok" }
--          }
--        }
--      }
--      #AllOutputs: (#struct){
--        reject: (string){ string }
--        resource: (string){ string }
--        retry: (#struct){
--          output: (#struct){ |((#struct){
--              reject: (string){ string }
--            }, (#struct){
--              resource: (string){ string }
--            }) }
--        }
--      }
--      #Output: (#struct){ |((#struct){
--          reject: (string){ string }
--        }, (#struct){
--          resource: (string){ string }
 +        retry: (struct){
-+          output: (#struct){
-+            reject: (string){ "ok" }
-+          }
-+        }
-+      }
-+      #AllOutputs: (#struct){
-+        reject: (string){ string }
-+        resource: (string){ string }
-+        retry: (#struct){
-+          output: (#struct){ |((#struct){
-+              reject: (string){ string }
-+            }, (#struct){
-+              resource: (string){ string }
-+            }, (#struct){
-+              retry: ~(issue1881.p1.#AllOutputs.retry)
-+            }) }
-+        }
-+      }
-+      #Output: (#struct){ |((#struct){
-+          reject: (string){ string }
-+        }, (#struct){
-+          resource: (string){ string }
-+        }, (#struct){
-+          retry: ~(issue1881.p1.#AllOutputs.retry)
-         }) }
-     }
-     p2: (struct){
-@@ -290,7 +287,7 @@
+           output: (#struct){
+             reject: (string){ "ok" }
+           }
+@@ -290,7 +283,7 @@
          }
        }
        o: (#struct){
@@ -852,7 +804,7 @@ diff old new
            output: (#struct){
              reject: (string){ "ok" }
            }
-@@ -320,7 +317,7 @@
+@@ -320,7 +313,7 @@
            resource: (string){ string }
          }) }
        o: (#struct){
@@ -871,10 +823,10 @@ diff old new
 -Reused: 1260
 -Allocs: 60
 -Retain: 145
-+Leaks:  782
-+Freed:  63
-+Reused: 63
-+Allocs: 782
++Leaks:  777
++Freed:  68
++Reused: 68
++Allocs: 777
 +Retain: 0
 
 -Unifications: 832
@@ -895,9 +847,6 @@ Conjuncts:    2525
 Disjuncts:    1404
 -- diff/explanation --
 B.a.children: now correctly marked as incomplete
--- diff/todo/p2 --
-issue1881.#AllOutputs.retry: additional entry.
-Might be error in practice and okay.
 -- out/eval --
 Errors:
 selfReferential.insertionError.A: field foo3 not allowed by earlier comprehension or reference cycle

cue/testdata/cycle/constraints.txtar

@@ -588,6 +588,7 @@ Conjuncts:    399
 Disjuncts:    213
 -- out/evalalpha --
 Errors:
+brokenRing.t1.p1.T.b: structural cycle
 cyclicRing.t1.T.b: structural cycle
 mutuallyTriggeringCycle.t1.x.c.b.b.b.b.b: structural cycle
 noCancelSelfInvoke.t1.x.c.b.b: structural cycle
@@ -848,22 +849,34 @@ Result:
     }
     issue1503: (_|_){
       // [structural cycle]
-      a: (#struct){
-        a: (#struct){
-          one: (#struct){
-            link: (#struct){
-              a: (#struct){
-                two: (#struct){
+      a: (_|_){
+        // [structural cycle]
+        a: (_|_){
+          // [structural cycle]
+          one: (_|_){
+            // [structural cycle]
+            link: (_|_){
+              // [structural cycle]
+              a: (_|_){
+                // [structural cycle]
+                two: (_|_){
+                  // [structural cycle]
                   link: ~(selfTriggerCycle.issue1503.#T)
                 }
-                b: (#struct){
-                  link: ~(selfTriggerCycle.issue1503.#T)
+                b: (_|_){
+                  // [structural cycle]
+                  link: (_|_){
+                    // [structural cycle]
+                  }
                 }
               }
             }
           }
-          b: (#struct){
-            link: ~(selfTriggerCycle.issue1503.#T)
+          b: (_|_){
+            // [structural cycle]
+            link: (_|_){
+              // [structural cycle]
+            }
           }
         }
       }
@@ -935,14 +948,20 @@ Result:
       }
     }
   }
-  brokenRing: (struct){
-    t1: (struct){
-      p1: (struct){
+  brokenRing: (_|_){
+    // [structural cycle]
+    t1: (_|_){
+      // [structural cycle]
+      p1: (_|_){
+        // [structural cycle]
         D: (struct){
           a?: ~(brokenRing.t1.p1.T)
         }
-        T: (struct){
-          b: ~(brokenRing.t1.p1.D)
+        T: (_|_){
+          // [structural cycle]
+          b: (_|_){
+            // [structural cycle] brokenRing.t1.p1.T.b: structural cycle
+          }
         }
       }
       p2: (struct){
@@ -996,9 +1015,9 @@ Result:
 diff old new
 --- old
 +++ new
-@@ -1,12 +1,10 @@
+@@ -1,12 +1,11 @@
  Errors:
--brokenRing.t1.p1.T.b: structural cycle
+ brokenRing.t1.p1.T.b: structural cycle
 -cyclicRing.t1.D.a.b: structural cycle
  cyclicRing.t1.T.b: structural cycle
 -mutuallyTriggeringCycle.t1.x.c.b.b.b.b: structural cycle
@@ -1012,7 +1031,7 @@ diff old new
  selfTriggerCycle.t1.#T.b.b: structural cycle
  selfTriggerCycle.t2.b.c.a: structural cycle
 
-@@ -152,18 +150,10 @@
+@@ -152,18 +151,10 @@
        #D: (#struct){
        }
        #E: (#struct){
@@ -1035,7 +1054,7 @@ diff old new
        }
        #S: (#struct){
          y: (#struct){
-@@ -201,18 +191,15 @@
+@@ -201,18 +192,15 @@
          // [structural cycle]
          c: (_|_){
            // [structural cycle]
@@ -1060,7 +1079,7 @@ diff old new
          }
        }
      }
-@@ -221,12 +208,7 @@
+@@ -221,12 +209,7 @@
      // [structural cycle]
      t1: (_|_){
        // [structural cycle]
@@ -1074,7 +1093,7 @@ diff old new
        #T: (_|_){
          // [structural cycle]
          b: (_|_){
-@@ -266,13 +248,7 @@
+@@ -266,13 +249,7 @@
                  c: (_|_){
                    // [structural cycle]
                    b: (_|_){
@@ -1089,49 +1108,47 @@ diff old new
                    }
                  }
                }
-@@ -283,25 +259,22 @@
-     }
-     issue1503: (_|_){
-       // [structural cycle]
--      a: (_|_){
--        // [structural cycle]
--        a: (_|_){
--          // [structural cycle]
+@@ -287,20 +264,29 @@
+         // [structural cycle]
+         a: (_|_){
+           // [structural cycle]
 -          b: (_|_){
 -            // [structural cycle]
 -            link: (_|_){
 -              // [structural cycle]
 -            }
 -          }
--          one: (_|_){
--            // [structural cycle]
--            link: (_|_){
--              // [structural cycle]
+           one: (_|_){
+             // [structural cycle]
+             link: (_|_){
+               // [structural cycle]
 -              a: (struct){
 -                two: (struct){
 -                }
 -              }
--            }
-+      a: (#struct){
-+        a: (#struct){
-+          one: (#struct){
-+            link: (#struct){
-+              a: (#struct){
-+                two: (#struct){
++              a: (_|_){
++                // [structural cycle]
++                two: (_|_){
++                  // [structural cycle]
 +                  link: ~(selfTriggerCycle.issue1503.#T)
 +                }
-+                b: (#struct){
-+                  link: ~(selfTriggerCycle.issue1503.#T)
++                b: (_|_){
++                  // [structural cycle]
++                  link: (_|_){
++                    // [structural cycle]
++                  }
 +                }
 +              }
 +            }
 +          }
-+          b: (#struct){
-+            link: ~(selfTriggerCycle.issue1503.#T)
++          b: (_|_){
++            // [structural cycle]
++            link: (_|_){
++              // [structural cycle]
+             }
            }
          }
-       }
-@@ -336,7 +309,10 @@
+@@ -336,7 +322,10 @@
                b: (_|_){
                  // [structural cycle]
                  b: (_|_){
@@ -1143,55 +1160,34 @@ diff old new
                  }
                }
              }
-@@ -370,34 +346,19 @@
-       }
-     }
-   }
--  brokenRing: (_|_){
--    // [structural cycle]
--    t1: (_|_){
--      // [structural cycle]
--      p1: (_|_){
--        // [structural cycle]
--        D: (struct){
+@@ -377,12 +366,7 @@
+       p1: (_|_){
+         // [structural cycle]
+         D: (struct){
 -          a?: (_|_){
 -            // [structural cycle]
 -            b: (_|_){
 -              // [structural cycle] brokenRing.t1.p1.D.a.b: structural cycle
 -            }
 -          }
--        }
--        T: (_|_){
--          // [structural cycle]
--          b: (_|_){
--            // [structural cycle] brokenRing.t1.p1.T.b: structural cycle
--          }
--        }
--      }
--      p2: (struct){
--        T: (struct){
++          a?: ~(brokenRing.t1.p1.T)
+         }
+         T: (_|_){
+           // [structural cycle]
+@@ -393,11 +377,7 @@
+       }
+       p2: (struct){
+         T: (struct){
 -          b: (struct){
 -            a?: (_|_){
 -              // [structural cycle] brokenRing.t1.p2.T.b.a: structural cycle
 -            }
 -          }
-+  brokenRing: (struct){
-+    t1: (struct){
-+      p1: (struct){
-+        D: (struct){
-+          a?: ~(brokenRing.t1.p1.T)
-+        }
-+        T: (struct){
-+          b: ~(brokenRing.t1.p1.D)
-+        }
-+      }
-+      p2: (struct){
-+        T: (struct){
 +          b: ~(brokenRing.t1.p2.D)
          }
          D: (struct){
            a?: (_|_){
-@@ -431,12 +392,7 @@
+@@ -431,12 +411,7 @@
        // [structural cycle]
        D: (_|_){
          // [structural cycle]

cue/testdata/cycle/structural.txtar

@@ -685,6 +685,7 @@ e4.b.0.0.0: conflicting values [{c:1}] and {} (mismatched types list and struct)
     ./in.cue:423:6
     ./in.cue:424:10
 e4.b.0.0.0: structural cycle
+issue2545.#B.A: structural cycle
 nestedList.v1e.y.0: 4 errors in empty disjunction:
 nestedList.v1e.y.0: conflicting values [[2],1] and int (mismatched types list and int):
     ./in.cue:438:11
@@ -1404,12 +1405,16 @@ Result:
       }
     }
   }
-  issue2545: (struct){
+  issue2545: (_|_){
+    // [structural cycle]
     #A: (#struct){
       B?: ~(issue2545.#B)
     }
-    #B: (#struct){
-      A: ~(issue2545.#A)
+    #B: (_|_){
+      // [structural cycle]
+      A: (_|_){
+        // [structural cycle] issue2545.#B.A: structural cycle
+      }
     }
   }
   e1: (_|_){
@@ -1869,7 +1874,7 @@ diff old new
  e1.a.c: structural cycle
  e1.b.c: structural cycle
  e2.a.c: structural cycle
-@@ -32,62 +37,94 @@
+@@ -32,62 +37,95 @@
      ./in.cue:415:5
      ./in.cue:416:5
  e3.b.c: structural cycle
@@ -1916,7 +1921,6 @@ diff old new
      ./in.cue:423:6
 -    ./in.cue:424:6
 -    ./in.cue:424:10
--issue2545.#B.A: structural cycle
 +    ./in.cue:424:10
 +e4.b.0.0.0: 4 errors in empty disjunction:
 +e4.b.0.0.0: conflicting values [{c:1}] and {c:1} (mismatched types list and struct):
@@ -1926,6 +1930,7 @@ diff old new
 +    ./in.cue:423:6
 +    ./in.cue:424:10
 +e4.b.0.0.0: structural cycle
+ issue2545.#B.A: structural cycle
  nestedList.v1e.y.0: 4 errors in empty disjunction:
 -nestedList.v1e.y.0: conflicting values int and [[2],1] (mismatched types int and list):
 +nestedList.v1e.y.0: conflicting values [[2],1] and int (mismatched types list and int):
@@ -1991,7 +1996,7 @@ diff old new
 
  Result:
  (_|_){
-@@ -129,10 +166,7 @@
+@@ -129,10 +167,7 @@
    a7: (struct){
      a: (string){ "foo" }
      b: (struct){
@@ -2003,7 +2008,7 @@ diff old new
        y: (string){ "foo" }
      }
      c: (struct){
-@@ -169,11 +203,17 @@
+@@ -169,11 +204,17 @@
      }
    }
    b4: (_|_){
@@ -2026,7 +2031,7 @@ diff old new
        }
      }
      x: (_|_){
-@@ -241,10 +281,9 @@
+@@ -241,10 +282,9 @@
          // [eval]
          0: (_|_){
            // [eval] b6.b.a.0: conflicting values 1 and [1] (mismatched types int and list):
@@ -2038,7 +2043,7 @@ diff old new
            0: (_|_){
              // [structural cycle] b6.b.a.0.0: structural cycle
            }
-@@ -262,11 +301,20 @@
+@@ -262,11 +302,20 @@
      }
    }
    b7: (_|_){
@@ -2064,7 +2069,7 @@ diff old new
        }
      }
      a: (_|_){
-@@ -277,9 +325,7 @@
+@@ -277,9 +326,7 @@
      }
    }
    b8: (struct){
@@ -2075,7 +2080,7 @@ diff old new
      a: (struct){
        f: (string){ string }
      }
-@@ -305,7 +351,7 @@
+@@ -305,7 +352,7 @@
      #ref: (#struct){
        ref: (string){ string }
      }
@@ -2084,7 +2089,7 @@ diff old new
          c: (#list){
            0: ((string|struct)){ |((string){ string }, (#struct){
                ref: (string){ string }
-@@ -328,7 +374,13 @@
+@@ -328,7 +375,13 @@
          }) }
      }
      c: (#struct){
@@ -2099,7 +2104,7 @@ diff old new
      }
      d: (struct){
        d: (struct){
-@@ -338,9 +390,7 @@
+@@ -338,9 +391,7 @@
    }
    b11: (struct){
      #list: (#struct){
@@ -2110,7 +2115,7 @@ diff old new
      }
    }
    b12: (struct){
-@@ -357,7 +407,11 @@
+@@ -357,7 +408,11 @@
            value: (int){ 3 }
            tail: (#struct){
              value: (int){ 4 }
@@ -2123,7 +2128,7 @@ diff old new
              sum: (int){ 4 }
            }
            sum: (int){ 7 }
-@@ -429,10 +483,7 @@
+@@ -429,10 +484,7 @@
            link: (#struct){
              a: (#struct){
                two: (#struct){
@@ -2135,7 +2140,7 @@ diff old new
                }
              }
            }
-@@ -506,10 +557,7 @@
+@@ -506,10 +558,7 @@
            link: (#struct){
              a: (#list){
                0: (#struct){
@@ -2147,7 +2152,7 @@ diff old new
                }
              }
            }
-@@ -600,47 +648,27 @@
+@@ -600,47 +649,27 @@
              // [structural cycle]
              h: (int){ int }
              t: (_|_){
@@ -2212,7 +2217,7 @@ diff old new
          c: (_|_){
            // [structural cycle]
            d: (_|_){
-@@ -667,28 +695,25 @@
+@@ -667,28 +696,25 @@
      }
      x: (_|_){
        // [structural cycle]
@@ -2246,7 +2251,7 @@ diff old new
        #List: (#struct){
          Next: (null){ null }
        }
-@@ -697,9 +722,7 @@
+@@ -697,9 +723,7 @@
        // [structural cycle]
        t1: (struct){
          #Foo: (#struct){
@@ -2257,7 +2262,7 @@ diff old new
          }
        }
        t2: (_|_){
-@@ -707,10 +730,7 @@
+@@ -707,10 +731,7 @@
          Foo: (_|_){
            // [structural cycle]
            ref: (_|_){
@@ -2269,7 +2274,7 @@ diff old new
            }
          }
        }
-@@ -717,9 +737,7 @@
+@@ -717,9 +738,7 @@
      }
      comprehension: (struct){
        #list: (#struct){
@@ -2280,7 +2285,7 @@ diff old new
        }
      }
    }
-@@ -745,8 +763,7 @@
+@@ -745,8 +764,7 @@
        }
      }
      let _schema_1#1 = (_|_){
@@ -2290,7 +2295,7 @@ diff old new
      }
    }
    fieldsSumInfinite: (_|_){
-@@ -757,7 +774,8 @@
+@@ -757,7 +775,8 @@
        fries: (float){ 2.00 }
        sprite: (float){ 1.00 }
        total: (_|_){
@@ -2300,44 +2305,32 @@ diff old new
        }
      }
    }
-@@ -772,27 +790,16 @@
+@@ -772,9 +791,7 @@
        head: (int){ 3 }
        tail: (struct){
          head: (int){ 2 }
 -        tail?: (_|_){
 -          // [structural cycle] listOptOK.a.tail.tail: structural cycle
 -        }
--      }
--    }
--  }
--  issue2545: (_|_){
--    // [structural cycle]
 +        tail?: ~(listOptOK.list)
-+      }
-+    }
-+  }
-+  issue2545: (struct){
+       }
+     }
+   }
+@@ -781,12 +798,7 @@
+   issue2545: (_|_){
+     // [structural cycle]
      #A: (#struct){
 -      B?: (_|_){
 -        // [structural cycle]
 -        A: (_|_){
 -          // [structural cycle] issue2545.#A.B.A: structural cycle
 -        }
 -      }
--    }
--    #B: (_|_){
--      // [structural cycle]
--      A: (_|_){
--        // [structural cycle] issue2545.#B.A: structural cycle
--      }
 +      B?: ~(issue2545.#B)
-+    }
-+    #B: (#struct){
-+      A: ~(issue2545.#A)
      }
-   }
-   e1: (_|_){
-@@ -831,11 +838,12 @@
+     #B: (_|_){
+       // [structural cycle]
+@@ -831,11 +843,12 @@
        // [eval] e3.a: conflicting values [a] and {c:a} (mismatched types list and struct):
        //     ./in.cue:412:5
        //     ./in.cue:413:5
@@ -2355,7 +2348,7 @@ diff old new
        }
      }
      b: (_|_){
-@@ -842,11 +850,12 @@
+@@ -842,11 +855,12 @@
        // [eval] e3.b: conflicting values [b] and {c:b} (mismatched types list and struct):
        //     ./in.cue:415:5
        //     ./in.cue:416:5
@@ -2373,7 +2366,7 @@ diff old new
        }
      }
    }
-@@ -855,38 +864,72 @@
+@@ -855,38 +869,72 @@
      a: (_|_){
        // [eval]
        0: (_|_){
@@ -2468,7 +2461,7 @@ diff old new
          0: (struct){
            c: (int){ 1 }
          }
-@@ -913,17 +956,16 @@
+@@ -913,17 +961,16 @@
          // [eval]
          0: (_|_){
            // [eval] nestedList.v1e.y.0: 4 errors in empty disjunction:
@@ -2491,7 +2484,7 @@ diff old new
            1: (int){ 1 }
          }
          1: (int){ 1 }
-@@ -935,17 +977,16 @@
+@@ -935,17 +982,16 @@
          // [eval]
          0: (_|_){
            // [eval] nestedList.v2e.y.0: 4 errors in empty disjunction:
@@ -2514,7 +2507,7 @@ diff old new
            1: (int){ 1 }
          }
          1: (int){ 1 }
-@@ -999,7 +1040,10 @@
+@@ -999,7 +1045,10 @@
          head: (int){ 3 }
          tail: (struct){
            head: (int){ 4 }
@@ -2526,7 +2519,7 @@ diff old new
          }
        }
      }
-@@ -1013,7 +1057,10 @@
+@@ -1013,7 +1062,10 @@
        head: (int){ 2 }
        tail: (struct){
          head: (int){ 3 }
@@ -2538,7 +2531,7 @@ diff old new
        }
      }
    }
-@@ -1027,8 +1074,12 @@
+@@ -1027,8 +1079,12 @@
        head: (int){ 2 }
        tail: (struct){ |((struct){
            head: (int){ 3 }
@@ -2553,7 +2546,7 @@ diff old new
          }, (struct){
            head: (int){ 3 }
          }) }
-@@ -1050,9 +1101,7 @@
+@@ -1050,9 +1106,7 @@
        // [structural cycle]
        f: (_|_){
          // [structural cycle]
@@ -2564,7 +2557,7 @@ diff old new
        }
        g: (_|_){
          // [structural cycle]
-@@ -1073,10 +1122,7 @@
+@@ -1073,10 +1127,7 @@
            x: (_){ _ }
            y: (_){ _ }
          }
@@ -2576,7 +2569,7 @@ diff old new
        }
      }
      t2: (struct){
-@@ -1089,10 +1135,7 @@
+@@ -1089,10 +1140,7 @@
            x: (_){ _ }
            y: (_){ _ }
          }
@@ -2588,7 +2581,7 @@ diff old new
        }
      }
      t3: (struct){
-@@ -1107,16 +1150,8 @@
+@@ -1107,16 +1155,8 @@
            y: (_){ _ }
            z: (_){ _ }
          }
@@ -2607,7 +2600,7 @@ diff old new
        }
      }
      t4: (struct){
-@@ -1132,51 +1167,11 @@
+@@ -1132,51 +1172,11 @@
              y: (_){ _ }
              z: (_){ _ }
            }
@@ -2664,7 +2657,7 @@ diff old new
        }
      }
      t5: (struct){
-@@ -1187,18 +1182,8 @@
+@@ -1187,18 +1187,8 @@
          }
        }
        C: (struct){
@@ -2685,7 +2678,7 @@ diff old new
        }
      }
    }
-@@ -1221,19 +1206,19 @@
+@@ -1221,19 +1211,19 @@
      }
    }
    n4: (struct){

cue/testdata/eval/disjunctions.txtar

@@ -623,9 +623,6 @@ Result:
         }, (#struct){
           _ok: (bool){ true }
           let Ok#2 = (bool){ true }
-        }, (#struct){
-          _ok: (bool){ true }
-          let Ok#2 = (bool){ true }
         }, (#struct){
           _ok: (bool){ true }
           let Ok#2multi = 〈0;_ok〉
@@ -733,16 +730,6 @@ diff old new
          }
        }
      }
-@@ -371,6 +353,9 @@
-           let Ok#2 = (bool){ true }
-         }, (#struct){
-           _ok: (bool){ true }
-+          let Ok#2 = (bool){ true }
-+        }, (#struct){
-+          _ok: (bool){ true }
-           let Ok#2multi = 〈0;_ok〉
-           x: (bool){ true }
-         }) }
 -- diff/todo/p1 --
 issue3597.t1.foo: duplicate disjunct
 -- diff/todo/p3 --

cue/testdata/resolve/048_builtins.txtar

@@ -134,10 +134,6 @@ stringListErrors.c.result: cannot use int (type int) as string in argument 2 to
 decimalListErrors.a.result: invalid list element 0 in argument 0 to call: cannot use value string (string) as number:
     ./in.cue:43:11
     ./in.cue:42:7
-issue3648.reduced.foo.a: error in call to list.Concat: not properly initialized (state: unprocessed, value: *adt.Vertex):
-    ./issue3648.cue:7:6
-issue3648.full.foo.allRedirects: error in call to list.Concat: not properly initialized (state: unprocessed, value: *adt.Vertex):
-    ./issue3648.cue:17:17
 
 Result:
 (_|_){
@@ -248,32 +244,25 @@ Result:
       }
     }
   }
-  issue3648: (_|_){
-    // [eval]
-    reduced: (_|_){
-      // [eval]
-      foo: (_|_){
-        // [eval]
-        a: (_|_){
-          // [eval] issue3648.reduced.foo.a: error in call to list.Concat: not properly initialized (state: unprocessed, value: *adt.Vertex):
-          //     ./issue3648.cue:7:6
+  issue3648: (struct){
+    reduced: (struct){
+      foo: (struct){
+        a: (#list){
+          0: (struct){
+          }
         }
         b: (#list){
           0: (struct){
           }
         }
       }
     }
-    full: (_|_){
-      // [eval]
+    full: (struct){
       #Redirect: (#struct){
         path?: (string){ string }
       }
-      foo: (_|_){
-        // [eval]
-        allRedirects: (_|_){
-          // [eval] issue3648.full.foo.allRedirects: error in call to list.Concat: not properly initialized (state: unprocessed, value: *adt.Vertex):
-          //     ./issue3648.cue:17:17
+      foo: (struct){
+        allRedirects: (#list){
         }
         redirects: (list){
         }
@@ -299,18 +288,7 @@ diff old new
      ./in.cue:20:14
      ./in.cue:20:24
  a3.a: invalid value "bar" (out of bound =~"oo"):
-@@ -26,6 +22,10 @@
- decimalListErrors.a.result: invalid list element 0 in argument 0 to call: cannot use value string (string) as number:
-     ./in.cue:43:11
-     ./in.cue:42:7
-+issue3648.reduced.foo.a: error in call to list.Concat: not properly initialized (state: unprocessed, value: *adt.Vertex):
-+    ./issue3648.cue:7:6
-+issue3648.full.foo.allRedirects: error in call to list.Concat: not properly initialized (state: unprocessed, value: *adt.Vertex):
-+    ./issue3648.cue:17:17
- 
- Result:
- (_|_){
-@@ -70,13 +70,9 @@
+@@ -70,13 +66,9 @@
      a: (_|_){
        // [eval] o3.a: 2 errors in empty disjunction:
        // o3.a: conflicting values "bar" and "foo":
@@ -324,48 +302,6 @@ diff old new
        //     ./in.cue:20:14
        //     ./in.cue:20:24
      }
-@@ -140,12 +136,15 @@
-       }
-     }
-   }
--  issue3648: (struct){
--    reduced: (struct){
--      foo: (struct){
--        a: (#list){
--          0: (struct){
--          }
-+  issue3648: (_|_){
-+    // [eval]
-+    reduced: (_|_){
-+      // [eval]
-+      foo: (_|_){
-+        // [eval]
-+        a: (_|_){
-+          // [eval] issue3648.reduced.foo.a: error in call to list.Concat: not properly initialized (state: unprocessed, value: *adt.Vertex):
-+          //     ./issue3648.cue:7:6
-         }
-         b: (#list){
-           0: (struct){
-@@ -153,12 +152,16 @@
-         }
-       }
-     }
--    full: (struct){
-+    full: (_|_){
-+      // [eval]
-       #Redirect: (#struct){
-         path?: (string){ string }
-       }
--      foo: (struct){
--        allRedirects: (#list){
-+      foo: (_|_){
-+        // [eval]
-+        allRedirects: (_|_){
-+          // [eval] issue3648.full.foo.allRedirects: error in call to list.Concat: not properly initialized (state: unprocessed, value: *adt.Vertex):
-+          //     ./issue3648.cue:17:17
-         }
-         redirects: (list){
-         }
 -- diff/todo/p2 --
 Missing error positions.
 -- out/eval --

internal/core/adt/unify.go

@@ -355,6 +355,10 @@ func (v *Vertex) unify(c *OpContext, needs condition, mode runMode) bool {
 		}
 		v.status = w.status
 
+		// Ensure that shared nodes comply to the same requirements as we
+		// need for the current node.
+		w.unify(c, needs, mode)
+
 		return true
 	}