From 7e5eab571e6e8e57928b40f535802aec04e04633 Mon Sep 17 00:00:00 2001
From: Andreas Rumpf <rumpf_a@web.de>
Date: Fri, 24 Sep 2021 16:27:34 +0200
Subject: [PATCH] closes #18690; make view types stricter [backport] (#18891)

* closes #18690

* don't allow capturing of view types [backport]
---
 compiler/lambdalifting.nim |  6 ++----
 tests/views/tviews1.nim    | 13 ++++++++++++-
 2 files changed, 14 insertions(+), 5 deletions(-)

diff --git a/compiler/lambdalifting.nim b/compiler/lambdalifting.nim
index c555cedfe1..a622f6de6b 100644
--- a/compiler/lambdalifting.nim
+++ b/compiler/lambdalifting.nim
@@ -12,7 +12,7 @@
 import
   intsets, strutils, options, ast, astalgo, msgs,
   idents, renderer, types, magicsys, lowerings, tables, modulegraphs, lineinfos,
-  transf, liftdestructors
+  transf, liftdestructors, typeallowed
 
 discard """
   The basic approach is that captured vars need to be put on the heap and
@@ -191,9 +191,7 @@ proc interestingVar(s: PSym): bool {.inline.} =
     s.typ.kind notin {tyStatic, tyTypeDesc}
 
 proc illegalCapture(s: PSym): bool {.inline.} =
-  result = skipTypes(s.typ, abstractInst).kind in
-                   {tyVar, tyOpenArray, tyVarargs, tyLent} or
-      s.kind == skResult
+  result = classifyViewType(s.typ) != noView or s.kind == skResult
 
 proc isInnerProc(s: PSym): bool =
   if s.kind in {skProc, skFunc, skMethod, skConverter, skIterator} and s.magic == mNone:
diff --git a/tests/views/tviews1.nim b/tests/views/tviews1.nim
index 49d79c5b58..3dbf664fc7 100644
--- a/tests/views/tviews1.nim
+++ b/tests/views/tviews1.nim
@@ -6,7 +6,8 @@ discard """
 2
 3
 3
-15'''
+15
+(oa: [1, 3, 4])'''
   targets: "c cpp"
 """
 
@@ -38,3 +39,13 @@ var y: var int = foo(x)
 y = 15
 echo foo(x)
 # bug #16132
+
+# bug #18690
+
+type
+  F = object
+    oa: openarray[int]
+
+let s1 = @[1,3,4,5,6]
+var test = F(oa: toOpenArray(s1, 0, 2))
+echo test