simplex-chat/plans/desktop-oshi-windows-npe.md

Desktop: crash at startup on Windows when WMI does not answer

Fixes #7580.

Problem

The desktop app exits at startup on some Windows 10 machines:

java.lang.ExceptionInInitializerError
    at com.jthemedetecor.OsThemeDetector.getDetector(OsThemeDetector.java:43)
    at chat.simplex.common.platform.Resources_desktopKt.<clinit>(Resources.desktop.kt:29)
    ...
Caused by: java.lang.NullPointerException: Cannot invoke "String.compareTo(String)" because "buildNumber" is null
    at oshi.software.os.OperatingSystem$OSVersionInfo.<init>(OperatingSystem.java:510)
    at oshi.software.os.windows.WindowsOperatingSystem.queryFamilyVersionInfo(WindowsOperatingSystem.java:172)
    ...
    at com.jthemedetecor.util.OsInfo.<clinit>(OsInfo.java:27)

Cause

jSystemThemeDetector:3.8 depends on oshi-core:5.8.6. Its OsInfo static initialiser calls OperatingSystem.getVersionInfo().

In oshi 5.8.6, WindowsOperatingSystem.queryFamilyVersionInfo() starts with buildNumber = null and sets it only if the WMI query for Win32_OperatingSystem returns a row. WmiQueryHandler.queryWMI returns an empty result on any COMException (invalid namespace/class, access denied, broken WMI repository or service) or on a timeout. The OSVersionInfo constructor then runs:

if ("10".equals(version) && buildNumber.compareTo("22000") >= 0) {

It throws when os.name is "Windows 10" and WMI returned nothing. So only machines with a failing WMI query crash; a healthy WMI returns the build number.

The app calls OsThemeDetector.getDetector() in top-level val initialisers (Resources.desktop.kt, Theme.desktop.kt). The failure is an Error raised while the class loads, so nothing catches it. settings lives in the same file, so the first preference read in runMigrations fails and the app exits.

Fix

Add com.github.oshi:oshi-core:6.4.13 to desktopMain. Gradle conflict resolution replaces the transitive 5.8.6 with it.

• The buildNumber.compareTo check is in every oshi release up to 6.3.0 and was removed in 6.3.1. There the constructor just stores the null build number.
• 6.4.13 is built against JNA 5.14.0, the version the app already pins (jna, jna-platform). 6.3.1 used 5.12.1 and 6.6.x uses 5.16.0.
• jSystemThemeDetector 3.8 uses only SystemInfo.<init>, getOperatingSystem, getCurrentPlatform, OperatingSystem.getFamily, getVersionInfo, OSVersionInfo.getVersion and PlatformEnum.{WINDOWS,MACOS,LINUX}. All of them exist unchanged in 6.4.13.

Verification

• new OSVersionInfo("10", "", null) throws the reported NPE with oshi 5.8.6 and returns 10 with 6.4.13.
• With 6.4.13, jSystemThemeDetector 3.8 and JNA 5.14.0 on the classpath, OsThemeDetector.getDetector() loads and returns a detector.
• :common:dependencyInsight --configuration desktopRuntimeClasspath --dependency oshi-core shows 5.8.6 -> 6.4.13.