fixes #20681

compiler/semexprs.nim

@@ -3077,8 +3077,6 @@ proc semExpr(c: PContext, n: PNode, flags: TExprFlags = {}, expectedType: PType
   of nkCurly: result = semSetConstr(c, n, expectedType)
   of nkBracket:
     result = semArrayConstr(c, n, flags, expectedType)
-    if n.typ != nil and n.typ.skipTypes(abstractRange).kind == tySequence:
-      result.typ = n.typ # keeps tySequence type for []
   of nkObjConstr: result = semObjConstr(c, n, flags, expectedType)
   of nkLambdaKinds: result = semProcAux(c, n, skProc, lambdaPragmas, flags)
   of nkDerefExpr: result = semDeref(c, n)

tests/objects/tobject_default_value.nim

@@ -418,21 +418,12 @@ template main {.dirty.} =
     var z {.noinit.}: Pure = Pure(id: 77)
     doAssert z.id == 77
 
+  block: # bug #20681
+    type A = object
+      d: DateTime = DateTime()
 
-  block:
-    type TokenData = object
-      campaignMemberships = Table[string, string]()
-
-    let x = default(TokenData)
-    doAssert x.campaignMemberships.len == 0
-
-  when false: # todo fixme
-    block:
-      type TokenData = object
-        campaignMemberships = newTable[string, string]()
-
-      let x = default(TokenData)
-      doAssert x.campaignMemberships.len == 0
+    let x = default(A)
+    doAssert $x == "(d: Uninitialized DateTime)"
 
 
 static: main()