From a7167def2397caac0c004c12fd20d675bbcc4d7a Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lukas=20Br=C3=BCbach?= <Bruebach.Lukas@bdosecurity.de>
Date: Fri, 12 Jun 2026 15:19:49 +0200
Subject: [PATCH] Another go.

Took 4 minutes
---
 cmake/NSIS.template.in | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/cmake/NSIS.template.in b/cmake/NSIS.template.in
index 7b52b7bcc..68af2da16 100644
--- a/cmake/NSIS.template.in
+++ b/cmake/NSIS.template.in
@@ -112,6 +112,18 @@ ${Else}
     StrCpy $ReinstallMode 0
 ${EndIf}
 
+; When launched with /R by the client, explicitly parse /D= from the raw
+; parameter string. Qt's QProcess::startDetached with a pre-formed command
+; string does not guarantee the NSIS stub's built-in /D= handler sees the
+; value, so we extract it ourselves here where GetOptions is reliable.
+${If} $ReinstallMode = 1
+    ClearErrors
+    ${GetOptions} $9 "/D=" $R1
+    ${IfNot} ${Errors}
+        StrCpy $InstDir $R1
+    ${EndIf}
+${EndIf}
+
 ${If} $InstDir == ""
     ; User did not use /D to specify a directory,
     ; we need to set a default based on the install mode