From cd22560af5f13a7c024b97e2f3de2b1fe2439eb3 Mon Sep 17 00:00:00 2001
From: metagn <metagngn@gmail.com>
Date: Sun, 8 Sep 2024 21:17:26 +0300
Subject: [PATCH] fix string literal assignment with different lengths on ARC
 (#24083)

fixes #24080
---
 lib/system/strs_v2.nim       |  2 +-
 tests/arc/tstringliteral.nim | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 1 deletion(-)
 create mode 100644 tests/arc/tstringliteral.nim

diff --git a/lib/system/strs_v2.nim b/lib/system/strs_v2.nim
index dbee107774c34..404b4f78dc675 100644
--- a/lib/system/strs_v2.nim
+++ b/lib/system/strs_v2.nim
@@ -166,7 +166,7 @@ proc setLengthStrV2(s: var NimStringV2, newLen: int) {.compilerRtl.} =
   s.len = newLen
 
 proc nimAsgnStrV2(a: var NimStringV2, b: NimStringV2) {.compilerRtl.} =
-  if a.p == b.p: return
+  if a.p == b.p and a.len == b.len: return
   if isLiteral(b):
     # we can shallow copy literals:
     frees(a)
diff --git a/tests/arc/tstringliteral.nim b/tests/arc/tstringliteral.nim
new file mode 100644
index 0000000000000..c5fac22d82c59
--- /dev/null
+++ b/tests/arc/tstringliteral.nim
@@ -0,0 +1,17 @@
+discard """
+  matrix: "--mm:arc; --mm:orc"
+"""
+
+block: # issue #24080
+  var a = (s: "a")
+  var b = "a"
+  a.s.setLen 0
+  b = a.s
+  doAssert b == ""
+
+block: # issue #24080, longer string
+  var a = (s: "abc")
+  var b = "abc"
+  a.s.setLen 2
+  b = a.s
+  doAssert b == "ab"