From 5eee3e06fc1972a3812e7fc60d9f30eed80f6dce Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Paulo?= <rockcavera@gmail.com>
Date: Sun, 21 Apr 2024 16:30:12 -0300
Subject: [PATCH] fix #23518 - `<expr> is` crashes nimsuggest (#23523)

This solution should resolve the nimsuggest crash issue. However,
perhaps the problem is in the parser?

fix #23518

(cherry picked from commit 60af04635f44e655c7928da36fc9394e11367d18)
---
 compiler/semexprs.nim | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/compiler/semexprs.nim b/compiler/semexprs.nim
index a179c68d7b..69f7efa970 100644
--- a/compiler/semexprs.nim
+++ b/compiler/semexprs.nim
@@ -512,8 +512,9 @@ proc isOpImpl(c: PContext, n: PNode, flags: TExprFlags): PNode =
   result.typ = n.typ
 
 proc semIs(c: PContext, n: PNode, flags: TExprFlags): PNode =
-  if n.len != 3:
+  if n.len != 3 or n[2].kind == nkEmpty:
     localError(c.config, n.info, "'is' operator takes 2 arguments")
+    return errorNode(c, n)
 
   let boolType = getSysType(c.graph, n.info, tyBool)
   result = n