From 2114414099993d5da4627645454214a7ff306f1e Mon Sep 17 00:00:00 2001
From: ringabout <43030857+ringabout@users.noreply.github.com>
Date: Fri, 26 Jan 2024 19:46:39 +0800
Subject: [PATCH] fixes #19977; rework inlining of 'var openarray' iterators
 for C++ (#23258)

fixes #19977

(cherry picked from commit f7c6e04cfbc44c225c123d724745840585561ac5)
---
 compiler/transf.nim              | 3 ++-
 tests/iter/titervaropenarray.nim | 2 +-
 2 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/compiler/transf.nim b/compiler/transf.nim
index 961ac49672..56d8d35abc 100644
--- a/compiler/transf.nim
+++ b/compiler/transf.nim
@@ -472,7 +472,8 @@ proc transformYield(c: PTransf, n: PNode): PNode =
 
 proc transformAddrDeref(c: PTransf, n: PNode, kinds: TNodeKinds): PNode =
   result = transformSons(c, n)
-  if c.graph.config.backend == backendCpp or sfCompileToCpp in c.module.flags: return
+  # inlining of 'var openarray' iterators; bug #19977
+  if n.typ.kind != tyOpenArray and (c.graph.config.backend == backendCpp or sfCompileToCpp in c.module.flags): return
   var n = result
   case n[0].kind
   of nkObjUpConv, nkObjDownConv, nkChckRange, nkChckRangeF, nkChckRange64:
diff --git a/tests/iter/titervaropenarray.nim b/tests/iter/titervaropenarray.nim
index ad1192bd80..b2fe71cebf 100644
--- a/tests/iter/titervaropenarray.nim
+++ b/tests/iter/titervaropenarray.nim
@@ -1,6 +1,6 @@
 discard """
   output: "123"
-  targets: "c"
+  targets: "c cpp"
 """
 # Try to break the transformation pass:
 iterator iterAndZero(a: var openArray[int]): int =