From 72e577dcc6a6733182059ab51b28a03c6077edc1 Mon Sep 17 00:00:00 2001
From: Lucas Fernandes Nogueira <lucas@tauri.studio>
Date: Wed, 4 May 2022 06:48:53 -0700
Subject: [PATCH] fix(bundler): properly reinstall files on MSI downgrades,
 closes #3868 (#4044)

---
 .changes/fix-windows-downgrades.md                    | 5 +++++
 tooling/bundler/src/bundle/windows/templates/main.wxs | 6 +++++-
 2 files changed, 10 insertions(+), 1 deletion(-)
 create mode 100644 .changes/fix-windows-downgrades.md

diff --git a/.changes/fix-windows-downgrades.md b/.changes/fix-windows-downgrades.md
new file mode 100644
index 000000000..c09942302
--- /dev/null
+++ b/.changes/fix-windows-downgrades.md
@@ -0,0 +1,5 @@
+---
+"tauri-bundler": patch
+---
+
+Fix app downgrades when using the Windows installer.
diff --git a/tooling/bundler/src/bundle/windows/templates/main.wxs b/tooling/bundler/src/bundle/windows/templates/main.wxs
index f6eea5204..3c0f76c9a 100644
--- a/tooling/bundler/src/bundle/windows/templates/main.wxs
+++ b/tooling/bundler/src/bundle/windows/templates/main.wxs
@@ -25,8 +25,12 @@
                  InstallScope="perMachine"
                  SummaryCodepage="!(loc.TauriCodepage)"/>
 
+        <!-- https://docs.microsoft.com/en-us/windows/win32/msi/reinstallmode -->
+        <!-- force all files to be reinstalled; rewrite all registry entries; reinstall all shortcuts -->
+        <Property Id="REINSTALLMODE" Value="amus" />
+
         {{#if allow_downgrades}}
-            <MajorUpgrade AllowDowngrades="yes" />
+            <MajorUpgrade AllowDowngrades="yes" Schedule="afterInstallInitialize" />
         {{else}}
             <MajorUpgrade DowngradeErrorMessage="!(loc.DowngradeErrorMessage)" AllowSameVersionUpgrades="yes" />
         {{/if}}