From 07b197958d89714aa8a7185b7a4f7087067fce99 Mon Sep 17 00:00:00 2001
From: Lorenz Stechauner <lorenz.stechauner@necronda.net>
Date: Tue, 11 Aug 2026 18:09:51 +0200
Subject: [PATCH] Printing: Try to duplex print with manual dialog

---
 Elwig/Helpers/Printing/Win32Printer.cs | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/Elwig/Helpers/Printing/Win32Printer.cs b/Elwig/Helpers/Printing/Win32Printer.cs
index 4bf2f7d..3e90a19 100644
--- a/Elwig/Helpers/Printing/Win32Printer.cs
+++ b/Elwig/Helpers/Printing/Win32Printer.cs
@@ -163,15 +163,17 @@ namespace Elwig.Helpers.Printing {
 
             public bool TrySetDuplex(Duplexing duplex) {
                 var devMode = Marshal.PtrToStructure<DEVMODE>(_devMode);
+                switch (duplex) {
+                    case Duplexing.OneSided: devMode.dmDuplex = DMDUP_SIMPLEX; break;
+                    case Duplexing.TwoSidedShortEdge: devMode.dmDuplex = DMDUP_HORIZONTAL; break;
+                    case Duplexing.TwoSidedLongEdge: devMode.dmDuplex = DMDUP_VERTICAL; break;
+                }
                 if ((devMode.dmFields & DM_DUPLEX) != 0) {
-                    switch (duplex) {
-                        case Duplexing.OneSided: devMode.dmDuplex = DMDUP_SIMPLEX; break;
-                        case Duplexing.TwoSidedShortEdge: devMode.dmDuplex = DMDUP_HORIZONTAL; break;
-                        case Duplexing.TwoSidedLongEdge: devMode.dmDuplex = DMDUP_VERTICAL; break;
-                    }
                     Marshal.StructureToPtr(devMode, _devMode, false);
                     return true;
                 } else {
+                    devMode.dmFields |= DM_DUPLEX;
+                    Marshal.StructureToPtr(devMode, _devMode, false);
                     return false;
                 }
             }