From 753e1ceff6b66d622cbe3ff8a946373299a0a86f Mon Sep 17 00:00:00 2001
From: WerWolv <werwolv98@gmail.com>
Date: Sat, 17 Jan 2026 21:47:06 +0100
Subject: [PATCH] build: Allow MSI installer to downgrade installations

---
 cmake/build_helpers.cmake              |  4 +-
 resources/dist/windows/WIX.template.in | 53 ++++++++++++++++++++++++++
 resources/dist/windows/wix_patch.xml   |  6 ---
 3 files changed, 56 insertions(+), 7 deletions(-)
 create mode 100644 resources/dist/windows/WIX.template.in
 delete mode 100644 resources/dist/windows/wix_patch.xml

diff --git a/cmake/build_helpers.cmake b/cmake/build_helpers.cmake
index 8340073fc..80feda4e9 100644
--- a/cmake/build_helpers.cmake
+++ b/cmake/build_helpers.cmake
@@ -202,12 +202,14 @@ macro(configurePackingResources)
             set(CPACK_PACKAGE_NAME "ImHex")
             set(CPACK_PACKAGE_VENDOR "WerWolv")
             set(CPACK_WIX_VERSION 4)
+            set(CPACK_WIX_PRODUCT_GUID "*")
             set(CPACK_WIX_UPGRADE_GUID "05000E99-9659-42FD-A1CF-05C554B39285")
             set(CPACK_WIX_PRODUCT_ICON "${PROJECT_SOURCE_DIR}/resources/dist/windows/icon.ico")
             set(CPACK_WIX_UI_BANNER "${PROJECT_SOURCE_DIR}/resources/dist/windows/wix_banner.png")
             set(CPACK_WIX_UI_DIALOG "${PROJECT_SOURCE_DIR}/resources/dist/windows/wix_dialog.png")
             set(CPACK_WIX_CULTURES "en-US;de-DE;ja-JP;it-IT;pt-BR;zh-CN;zh-TW;ru-RU")
-            set(CPACK_WIX_PATCH_FILE "${PROJECT_SOURCE_DIR}/resources/dist/windows/wix_patch.xml")
+            set(CPACK_WIX_TEMPLATE "${PROJECT_SOURCE_DIR}/resources/dist/windows/WIX.template.in")
+            set(CPACK_WIX_EXTENSIONS "WixToolset.UI.wixext")
 
             set(CPACK_PACKAGE_INSTALL_DIRECTORY "ImHex")
             set_property(INSTALL "$<TARGET_FILE_NAME:main>"
diff --git a/resources/dist/windows/WIX.template.in b/resources/dist/windows/WIX.template.in
new file mode 100644
index 000000000..27b897ee8
--- /dev/null
+++ b/resources/dist/windows/WIX.template.in
@@ -0,0 +1,53 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<?include "cpack_variables.wxi"?>
+
+<Wix
+    xmlns="http://wixtoolset.org/schemas/v4/wxs"@CPACK_WIX_CUSTOM_XMLNS_EXPANDED@
+    >
+
+    <Package
+        Name="$(var.CPACK_PACKAGE_NAME)"
+        Version="$(var.CPACK_PACKAGE_VERSION)"
+        Manufacturer="$(var.CPACK_PACKAGE_VENDOR)"
+        UpgradeCode="$(var.CPACK_WIX_UPGRADE_GUID)"
+        ProductCode="$(var.CPACK_WIX_PRODUCT_GUID)"
+        InstallerVersion="500"
+        Language="1033"
+        Compressed="yes"
+        >
+
+        <?ifndef CPACK_WIX_CAB_PER_COMPONENT?>
+        <Media Id="1" Cabinet="media1.cab" EmbedCab="yes"/>
+        <?endif?>
+
+        <MajorUpgrade
+            Schedule="afterInstallInitialize"
+            AllowDowngrades="yes"/>
+
+        <Property Id="REINSTALLMODE" Value="amus"/>
+
+        <WixVariable Id="WixUILicenseRtf" Value="$(var.CPACK_WIX_LICENSE_RTF)"/>
+        <Property Id="WIXUI_INSTALLDIR" Value="INSTALL_ROOT"/>
+
+        <?ifdef CPACK_WIX_PRODUCT_ICON?>
+        <Property Id="ARPPRODUCTICON" Value="ProductIcon.ico" />
+        <Icon Id="ProductIcon.ico" SourceFile="$(var.CPACK_WIX_PRODUCT_ICON)"/>
+        <?endif?>
+
+        <?ifdef CPACK_WIX_UI_BANNER?>
+        <WixVariable Id="WixUIBannerBmp" Value="$(var.CPACK_WIX_UI_BANNER)"/>
+        <?endif?>
+
+        <?ifdef CPACK_WIX_UI_DIALOG?>
+        <WixVariable Id="WixUIDialogBmp" Value="$(var.CPACK_WIX_UI_DIALOG)"/>
+        <?endif?>
+
+        <FeatureRef Id="ProductFeature" />
+
+        <ui:WixUI Id="WixUI_InstallDir" />
+
+        <?include "properties.wxi"?>
+        <?include "product_fragment.wxi"?>
+    </Package>
+</Wix>
\ No newline at end of file
diff --git a/resources/dist/windows/wix_patch.xml b/resources/dist/windows/wix_patch.xml
deleted file mode 100644
index ff0219ba5..000000000
--- a/resources/dist/windows/wix_patch.xml
+++ /dev/null
@@ -1,6 +0,0 @@
-<CPackWiXPatch>
-    <CPackWiXFragment Id="#PRODUCT">
-        <SetProperty Id="REINSTALL" Value="ALL" After="CostFinalize" />
-        <SetProperty Id="REINSTALLMODE" Value="amus" After="CostFinalize" />
-    </CPackWiXFragment>
-</CPackWiXPatch>
\ No newline at end of file