[Bug 46508] New: wine uninstaller crashes when attempting to remove apps/ games installed through NSIS installer

https://bugs.winehq.org/show_bug.cgi?id=46508

Bug ID: 46508
           Summary: wine uninstaller crashes when attempting to remove
                    apps/games installed through NSIS installer
           Product: Wine-staging
           Version: 4.0
          Hardware: x86
               URL: https://sourceforge.net/projects/apexdc/files/ApexDC%2
                    B%2B/1.2.1/ApexDC%2B%2B_1.2.1_setup.exe/download
                OS: Linux
            Status: NEW
          Keywords: download, Installer
          Severity: normal
          Priority: P2
         Component: -unknown
          Assignee: [e-mail]
          Reporter: [e-mail]
                CC: [e-mail], [e-mail]
      Distribution: ArchLinux

Created attachment 63358
  --> https://bugs.winehq.org/attachment.cgi?id=63358
backtrace

I came across this problem when I was trying to uninstall some of my games
which were obtained from DotEmu. Apparently, their games was using an older
version of the NSIS (Nullsoft Scriptable Install System) installer (v2.37).

The problem: I'm starting with 'wine uninstaller' and select the game to be
removed. I click on the <Modify/Repair> button which launches the NSIS
uninstaller program. At this point Wine's uninstaller process crashes leaving
the NSIS uninstaller still running and functioning. Despite of the crash
removing of the selected program was successful.

The bug is not present in vanilla Wine, only in Staging.

The patch to blame:
https://github.com/wine-staging/wine-staging/blob/master/patches/user32-msgb...

To reproduce the problem I dug up an old version of ApexDC++ . The installer is
NSIS v2.45, but the same problem is present.

https://sourceforge.net/projects/apexdc/files/ApexDC%2B%2B/1.2.1/ApexDC%2B%2...

ApexDC++_1.2.1_setup.exe
mdsum: 5867d2696df30a27f7d533caffd12af0