From de47861fe373e553beacf579652b18c77510f0cb Mon Sep 17 00:00:00 2001
From: Krzysztof Kondrak <krzysztof.kondrak@gmail.com>
Date: Mon, 28 Dec 2015 16:50:51 +0100
Subject: [PATCH] Ignore the "Class already exists" error in multiple-window
 application

---
 src/windows.rs | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/src/windows.rs b/src/windows.rs
index 9444f89..0a4afca 100644
--- a/src/windows.rs
+++ b/src/windows.rs
@@ -249,8 +249,14 @@ impl Window {
             };
 
             if user32::RegisterClassW(&class) == 0 {
-                println!("Unable to register class, error {}", kernel32::GetLastError() as u32);
-                return None;
+                let err_code = kernel32::GetLastError() as u32;
+                
+                // ignore the "Class already exists" error for multiple windows
+                if err_code != 1410
+                {
+                    println!("Unable to register class, error {}", kernel32::GetLastError() as u32);
+                    return None;
+                }
             }
 
             let new_width = width * scale_factor as usize;