From 99eadd7609f1fa0e905f4239405ec63b24e992a0 Mon Sep 17 00:00:00 2001
From: ramox81 <184937705+ramox81@users.noreply.github.com>
Date: Tue, 22 Sep 2026 13:40:42 +0300
Subject: [PATCH] SHELL: do not index an empty selection when the command
 starts

`bool::then_some` evaluates its argument eagerly, so starting SHELL or
SOLIDEDIT with nothing selected indexed an empty vector and aborted the
application. The single-solid target now comes from a slice match.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
---
 src/app/commands/draw.rs | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/app/commands/draw.rs b/src/app/commands/draw.rs
index c51425fc7..cd0655e1c 100644
--- a/src/app/commands/draw.rs
+++ b/src/app/commands/draw.rs
@@ -2006,7 +2006,13 @@ impl OpenCADStudio {
                         )
                     })
                     .collect::<Vec<_>>();
-                let target = (selected.len() == 1).then_some(selected[0]);
+                // `then_some` evaluates its argument eagerly: indexing an empty
+                // selection here crashed the app when SHELL was started with
+                // nothing selected.
+                let target = match selected.as_slice() {
+                    [handle] => Some(*handle),
+                    _ => None,
+                };
                 let new_cmd = if cmd == "SHELL" {
                     ShellCommand::direct(target)
                 } else {