From 0cf39669df6334e4aa1de274d7eac4865719b859 Mon Sep 17 00:00:00 2001
From: Bung <crc32@qq.com>
Date: Sun, 2 Oct 2022 05:19:07 +0800
Subject: [PATCH] Fix #19224 For loops over a hardcoded empty array crash the
 compiler (#20476)

* Fix #11684 For loops over a hardcoded empty array crash the compiler

* Update t19224.nim

(cherry picked from commit 567c3f055ded0d81d15d6d5bc18377ca8c607c6d)
---
 compiler/semstmts.nim    |  3 +++
 tests/errmsgs/t19224.nim | 12 ++++++++++++
 2 files changed, 15 insertions(+)
 create mode 100644 tests/errmsgs/t19224.nim

diff --git a/compiler/semstmts.nim b/compiler/semstmts.nim
index b628bd1c18..7b5b2f0bc9 100644
--- a/compiler/semstmts.nim
+++ b/compiler/semstmts.nim
@@ -767,6 +767,9 @@ proc semForVars(c: PContext, n: PNode; flags: TExprFlags): PNode =
   var iterAfterVarLent = iter.skipTypes({tyGenericInst, tyAlias, tyLent, tyVar})
   # n.len == 3 means that there is one for loop variable
   # and thus no tuple unpacking:
+  if iterAfterVarLent.kind == tyEmpty:
+    localError(c.config, n[^2].info, "cannot infer element type of $1" %
+               renderTree(n[^2], {renderNoComments}))
   if iterAfterVarLent.kind != tyTuple or n.len == 3:
     if n.len == 3:
       if n[0].kind == nkVarTuple:
diff --git a/tests/errmsgs/t19224.nim b/tests/errmsgs/t19224.nim
new file mode 100644
index 0000000000..7a9ecb2e70
--- /dev/null
+++ b/tests/errmsgs/t19224.nim
@@ -0,0 +1,12 @@
+discard """
+cmd: "nim check --hints:off $file"
+errormsg: ""
+nimout: '''
+t19224.nim(10, 10) Error: cannot infer element type of items([])
+t19224.nim(12, 10) Error: cannot infer element type of items(@[])
+'''
+"""
+
+for _ in []: discard
+
+for _ in @[]: discard