From fe63de3ed75513e8791451824b79dc1579b438e0 Mon Sep 17 00:00:00 2001
From: Filip Zubik <filip@x9.cz>
Date: Tue, 24 Mar 2026 14:33:47 +0100
Subject: [PATCH] fix: clear wallpaper cache and add logging to DesktopInfo
 render

Windows reuses TranscodedWallpaper cache and ignores updated BMP
if the path stays the same. Clear cache before SystemParametersInfo
so wallpaper always reloads.

Add per-run logging to desktopinfo.log for diagnostics.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
---
 flash/scripts/07-desktop-info.ps1 | 23 ++++++++++++++++++++++-
 scripts/07-desktop-info.ps1       | 23 ++++++++++++++++++++++-
 2 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/flash/scripts/07-desktop-info.ps1 b/flash/scripts/07-desktop-info.ps1
index 7c379aa..84f2e7f 100644
--- a/flash/scripts/07-desktop-info.ps1
+++ b/flash/scripts/07-desktop-info.ps1
@@ -31,6 +31,12 @@ $renderContent = @'
 # Runs on every user logon via Scheduled Task.
 
 $ErrorActionPreference = "Continue"
+$LogFile = "C:\Windows\Setup\Scripts\desktopinfo.log"
+function Write-Log {
+    param([string]$Message, [string]$Level = "INFO")
+    Add-Content -Path $LogFile -Value "[$(Get-Date -Format 'HH:mm:ss')] [$Level] $Message" -Encoding UTF8
+}
+Write-Log "DesktopInfo render started" -Level INFO
 
 Add-Type -AssemblyName System.Drawing
 Add-Type -AssemblyName System.Windows.Forms
@@ -46,6 +52,7 @@ public class WallpaperApi {
 # -----------------------------------------------------------------------
 # Collect system info
 # -----------------------------------------------------------------------
+Write-Log "Collecting system info"
 $hostname   = $env:COMPUTERNAME
 $userDomain = $env:USERDOMAIN
 $userName   = $env:USERNAME
@@ -69,12 +76,15 @@ $domain = if ($csInfo -and $csInfo.PartOfDomain) { $csInfo.Domain } `
           elseif ($csInfo -and $csInfo.Workgroup) { $csInfo.Workgroup.ToLower() } `
           else { "N/A" }
 
+Write-Log "hostname=$hostname user=$loggedUser os=$osName ram=$($ramGB)GB cpu=${cpuCount}x${cpuSpeed}MHz ips=$ips domain=$domain"
+
 # -----------------------------------------------------------------------
 # Screen dimensions
 # -----------------------------------------------------------------------
 $screen = [System.Windows.Forms.Screen]::PrimaryScreen
 $width  = if ($screen) { $screen.Bounds.Width  } else { 1920 }
 $height = if ($screen) { $screen.Bounds.Height } else { 1080 }
+Write-Log "screen=${width}x${height}"
 
 # -----------------------------------------------------------------------
 # Create bitmap and graphics context
@@ -134,11 +144,22 @@ $g.Dispose()
 # Save and set as wallpaper
 # -----------------------------------------------------------------------
 $bmpPath = "C:\Windows\Setup\Scripts\desktopinfo.bmp"
+Write-Log "Saving BMP: $bmpPath"
 $bmp.Save($bmpPath, [System.Drawing.Imaging.ImageFormat]::Bmp)
 $bmp.Dispose()
 
+# Clear Windows wallpaper cache so it reloads from our BMP
+# Without this, Windows reuses TranscodedWallpaper and ignores the updated file
+$transcodedPath = "$env:APPDATA\Microsoft\Windows\Themes\TranscodedWallpaper"
+if (Test-Path $transcodedPath) {
+    Remove-Item $transcodedPath -Force -ErrorAction SilentlyContinue
+    Write-Log "Cleared TranscodedWallpaper cache"
+}
+
 # SPI_SETDESKTOPWALLPAPER=20, SPIF_UPDATEINIFILE|SPIF_SENDCHANGE=3
-[WallpaperApi]::SystemParametersInfo(20, 0, $bmpPath, 3) | Out-Null
+$result = [WallpaperApi]::SystemParametersInfo(20, 0, $bmpPath, 3)
+Write-Log "SystemParametersInfo result: $result"
+Write-Log "DesktopInfo render complete" -Level INFO
 '@
 
 $renderContent | Set-Content -Path $RenderScript -Encoding UTF8 -Force
diff --git a/scripts/07-desktop-info.ps1 b/scripts/07-desktop-info.ps1
index 7c379aa..84f2e7f 100644
--- a/scripts/07-desktop-info.ps1
+++ b/scripts/07-desktop-info.ps1
@@ -31,6 +31,12 @@ $renderContent = @'
 # Runs on every user logon via Scheduled Task.
 
 $ErrorActionPreference = "Continue"
+$LogFile = "C:\Windows\Setup\Scripts\desktopinfo.log"
+function Write-Log {
+    param([string]$Message, [string]$Level = "INFO")
+    Add-Content -Path $LogFile -Value "[$(Get-Date -Format 'HH:mm:ss')] [$Level] $Message" -Encoding UTF8
+}
+Write-Log "DesktopInfo render started" -Level INFO
 
 Add-Type -AssemblyName System.Drawing
 Add-Type -AssemblyName System.Windows.Forms
@@ -46,6 +52,7 @@ public class WallpaperApi {
 # -----------------------------------------------------------------------
 # Collect system info
 # -----------------------------------------------------------------------
+Write-Log "Collecting system info"
 $hostname   = $env:COMPUTERNAME
 $userDomain = $env:USERDOMAIN
 $userName   = $env:USERNAME
@@ -69,12 +76,15 @@ $domain = if ($csInfo -and $csInfo.PartOfDomain) { $csInfo.Domain } `
           elseif ($csInfo -and $csInfo.Workgroup) { $csInfo.Workgroup.ToLower() } `
           else { "N/A" }
 
+Write-Log "hostname=$hostname user=$loggedUser os=$osName ram=$($ramGB)GB cpu=${cpuCount}x${cpuSpeed}MHz ips=$ips domain=$domain"
+
 # -----------------------------------------------------------------------
 # Screen dimensions
 # -----------------------------------------------------------------------
 $screen = [System.Windows.Forms.Screen]::PrimaryScreen
 $width  = if ($screen) { $screen.Bounds.Width  } else { 1920 }
 $height = if ($screen) { $screen.Bounds.Height } else { 1080 }
+Write-Log "screen=${width}x${height}"
 
 # -----------------------------------------------------------------------
 # Create bitmap and graphics context
@@ -134,11 +144,22 @@ $g.Dispose()
 # Save and set as wallpaper
 # -----------------------------------------------------------------------
 $bmpPath = "C:\Windows\Setup\Scripts\desktopinfo.bmp"
+Write-Log "Saving BMP: $bmpPath"
 $bmp.Save($bmpPath, [System.Drawing.Imaging.ImageFormat]::Bmp)
 $bmp.Dispose()
 
+# Clear Windows wallpaper cache so it reloads from our BMP
+# Without this, Windows reuses TranscodedWallpaper and ignores the updated file
+$transcodedPath = "$env:APPDATA\Microsoft\Windows\Themes\TranscodedWallpaper"
+if (Test-Path $transcodedPath) {
+    Remove-Item $transcodedPath -Force -ErrorAction SilentlyContinue
+    Write-Log "Cleared TranscodedWallpaper cache"
+}
+
 # SPI_SETDESKTOPWALLPAPER=20, SPIF_UPDATEINIFILE|SPIF_SENDCHANGE=3
-[WallpaperApi]::SystemParametersInfo(20, 0, $bmpPath, 3) | Out-Null
+$result = [WallpaperApi]::SystemParametersInfo(20, 0, $bmpPath, 3)
+Write-Log "SystemParametersInfo result: $result"
+Write-Log "DesktopInfo render complete" -Level INFO
 '@
 
 $renderContent | Set-Content -Path $RenderScript -Encoding UTF8 -Force