From 43a8b62a241046cb533e9ff07c56949ef71ffb59 Mon Sep 17 00:00:00 2001
From: stefan schippers <stefan.schippers@gmail.com>
Date: Wed, 26 Feb 2025 16:01:32 +0100
Subject: [PATCH] proc to_eng: return arg as is if not valid expression

---
 src/xschem.tcl | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/src/xschem.tcl b/src/xschem.tcl
index f2688bd2..4a908d8c 100644
--- a/src/xschem.tcl
+++ b/src/xschem.tcl
@@ -628,6 +628,9 @@ proc from_eng {i} {
 ## convert number to engineering form
 proc to_eng {args} {
   set suffix {}
+  if { [catch {[uplevel #0 expr [join $args]]} i] } {
+    return $args
+  }
   set i [uplevel #0 expr [join $args]]
   set absi [expr {abs($i)}]