Installer: Improve minor-upgrade experience

[Rondom]

I am sorry that I do not have any concrete suggestions here. I think this is a good issue for a downstream user of Dokan without any kernel skills to contribute to the project ;-).

Updating from one version, e.g. 1.x.x to another minor (1.y.z) or minor-minor (1.x.y) version is currently not very smooth.

Current behaviour is:

• Installation fails with error message telling him what to do
• User needs to go to Programs/Features to uninstall the old version
• Reboot
• Install new version

We cannot reliably replace the running Dokan driver, even if the driver supported unloading/PnP, because there might still be volumes mounted.

I am not familiar with MSI, but maybe it possible to automate this. Contributions welcome ;-)
Back from my dusty memory I remember a mechanism to exchange files during boot to avoid the Windows-problem of not being able to replace files that are in use. At least that is how it worked in Windows 9x/ME using WININIT.EXE/INI (there you see how outdated my knowledge is....).

I think that 20 years later maybe MSI provides a transaction-safe way of accomplishing a clean upgrade i.e. automating the upgrade/reinstall making sure that everything is consistent i.e. in case of failure either the old or new version are installed and not a mish-mash of both.

[js69]

See answer to #322 - this should be handled in a custom bootstrapper.

For my own application's bundle I have created a IsDokanInstalled method to show a warning in case an older Dokan version than the one in the bundle is detected.

[Rondom]

Ooooh 😢 I guess I was too naïve 😄

Maybe we can leave those issues open nonetheless? I mean, maybe some of the downstream users are willing to contribute a solution Dokan can use for its bootstrapper as well? Downstream projects can then decide whether to use the Dokan bootstrapper or to incorporate a similar mechanism into their bootstrapper.

Here is what my googling found:
http://stackoverflow.com/questions/16166186/wix-burn-after-restart-force-reboot-continuing-installation

[Rondom]

For example I see that @keybase (@zanderz, @taruti) has some code in their bootstrapper for detecting old versions. Which versions, I don't know...

/~https://github.com/keybase/client/blob/master/packaging/windows/WIXInstallers/KeybaseBundle/Bundle.wxs

[js69]

They Keybase stuff searches for a fixed product code which means it finds only a very specific Dokan setup version.
Stub code for what my custom bootstrapper does to check Dokan1 installs generically:

string windowspath = Environment.GetEnvironmentVariable("windir");
string dokansyspath = Path.Combine(windowspath, @"System32\drivers\dokan1.sys");
if (Environment.Is64BitOperatingSystem)
{
    dokansyspath = Path.Combine(windowspath, @"Sysnative\drivers\dokan1.sys");
}
bool dokan1SysExists = MyFileExists(dokansyspath);
if (dokan1SysExists)
{
    Log(LogLevel.Verbose, "Dokan driver file exists: " + dokansyspath);
}

string dokanProductCode = FindUninstallProductCode("Dokan Library");
string dokanDisplayVersion = String.Empty;
string dokanFullVersion = String.Empty;
string dokanSetupVersion = GetBundleString("DokanVersion");

if (!String.IsNullOrEmpty(dokanProductCode))
{
    dokanFullVersion = GetRegvalueContent("HKLM", @"Software\Microsoft\Windows\CurrentVersion\Uninstall\" + dokanProductCode, "DisplayVersion");
    if (String.IsNullOrEmpty(dokanFullVersion))
    {
        dokanFullVersion = GetRegvalueContent("HKLM", @"Software\Microsoft\Windows\CurrentVersion\Uninstall\" + dokanProductCode, "FullVersion");
        Log(LogLevel.Verbose, "Dokan FullVersion=" + dokanFullVersion);
    }
    else
    {
        Log(LogLevel.Verbose, "Dokan DisplayVersion=" + dokanFullVersion);
    }

    if (String.IsNullOrEmpty(dokanFullVersion))
    {
        Log(LogLevel.Verbose, "No Dokan DisplayVersion of FullVersion found");
    }
    else
    {
        if (!String.IsNullOrEmpty(dokanSetupVersion))
        {
            Log(LogLevel.Verbose, "Bundle DokanVersion=" + dokanSetupVersion);
            Version installedDokanVersion = new Version(dokanFullVersion);
            Version setupDokanVersion = new Version(dokanSetupVersion);
            var compareresult = setupDokanVersion.CompareTo(installedDokanVersion);
            if (compareresult == 0)
            {
                Log(LogLevel.Verbose, "Same DokanVersion installed and in Bundle, will be skipped during setup");
                dokan1SysExists = false;
            }
            else if (compareresult > 0)
            {
                Log(LogLevel.Verbose, "Newer DokanVersion in Bundle than already installed");
                string errorMessage = ResolveText("ErrorDokanDetected");
                BootstrapperDispatcher.BeginInvoke(new Action(() => FatalErrorMessage("DokanVersionError", errorMessage)));
            }
            else if (compareresult < 0)
            {
                Log(LogLevel.Verbose, "Older DokanVersion in Bundle than already installed");
                dokan1SysExists = false;
            }
        }
        else
        {
            Log(LogLevel.Verbose, "No Bundle DokanVersion found");
        }
    }
}
else
{
    Log(LogLevel.Verbose, "No Dokan ProductCode found");
}

if (dokan1SysExists)
{
    string errorMessage = ResolveText("ErrorDokanDetected");

    // show warning, then terminate
    BootstrapperDispatcher.BeginInvoke(new Action(() => FatalErrorMessage("DokanVersionError", errorMessage)));
}