util:CloseApplication is looking for process in all sessions, not only in current session

[HamletHakobyan]

• Which version of WiX are you building with?

v3.11.1.2318

• Which version of Visual Studio are you building with (if any)?

v16.6.2

• Which version of the WiX Toolset Visual Studio Extension are you building with (if any)?

2019

• Which version of .NET are you building with?

v4.7

• If the problem occurs when installing your packages built with WiX, what is the version of Windows the package is running on?

Windows Server 2016 v1607

• Describe the problem and the steps to reproduce it.

I have a CloseApplication action declared as follow:

(NOT Installed) AND (NOT REINSTALL) AND (NOT WIX_UPGRADE_DETECTED)

There are two users that are logged in (two active sessions). When in the first session I open Outlook and have trying to install my app in per user scenario on second session, the msi installer ask me to close Outlook inspite of that I have no opened Outlook in the current session.

• Describe the behavior you expected and how it differed from the actual behavior.

I've expected to see prompt to close Outlook only if it is running in the current session. So the util shouldn't search the Outlook process system-wide but only in the current session.

[HamletHakobyan]

Ok.

I probably found to cause of issue. CloseApplication is searching for processes by name using CreateToolhelp32Snapshot function from Tlhelp32.h passing TH32CS_SNAPPROCESS. From Microsoft docs:

• TH32CS_SNAPPROCESS - Includes all processes in the system in the snapshot. To enumerate the processes, see Process32First.

After that we sent close messages to all processes found by search. Instead, IMO, we need to filter out processes by using ProcessIdToSessionId function to close applications only from current session.

[barnson]

Add an option to allow per-user and per-machine packages to restrict to the current session.