Fix crash when run with multiple monitors

1 files changed, 10 insertions, 4 deletions

diff --git a/src/clients/mod.rs b/src/clients/mod.rs
index 37a88c0..053b4de 100644
--- a/src/clients/mod.rs
+++ b/src/clients/mod.rs
@@ -359,11 +359,17 @@ impl ClientState {
     /// Set the new amount of screens, without unmanaging any clients.
     fn truncate_screens(&mut self, new_size: usize) {
         // hack: working around double borrow stuff
-        let mut moved_clients = vec![];
-        for old in self.mons.drain(new_size - self.mons.len()..self.mons.len()) {
-            moved_clients.extend(old.clients.into_iter());
+        if new_size < self.mons.len() {
+            let mut moved_clients = vec![];
+            for old in self.mons.drain(new_size - self.mons.len()..self.mons.len()) {
+                moved_clients.extend(old.clients.into_iter());
+            }
+            self.mons[0].clients.extend(moved_clients);
+        } else if new_size > self.mons.len() {
+            for _ in 0..new_size - self.mons.len() {
+                self.mons.push(MonitorInfo::default());
+            }
         }
-        self.mons[0].clients.extend(moved_clients);
     }
 
     /// Set the given screen's geometry, resizing the monitor list if necessary.