Make sure IE and Engine are actually being closed by custom action

installer/src/installer-lib/process.cpp

 #include <stdexcept>
 #include <functional>
 #include <wctype.h>
 // <thread> is C++11, but implemented in VS2012
 #include <thread>
 
 #include "installer-lib.h"
 #include "process.h"
+#include "handle.h"
+#include "session.h"
 
 //-------------------------------------------------------
 //-------------------------------------------------------
 typedef int (__stdcall *IsImmersiveDynamicFunc)(HANDLE);
 bool process_by_any_exe_not_immersive::operator()( const PROCESSENTRY32W & process )
 {
   if (processNames.find(process.szExeFile) != processNames.end())
   {   
     // Make sure the process is still alive
-    HANDLE procHandle = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, process.th32ProcessID);
+    Windows_Handle procHandle = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, process.th32ProcessID);
     if ((procHandle == NULL) || (procHandle == INVALID_HANDLE_VALUE)) return false;
 
     DWORD exitCode;
     if (!GetExitCodeProcess(procHandle, &exitCode)) return false;
 
     if (exitCode != STILL_ACTIVE) return false;
 
     // Check if this is a Windows Store app process (we don't care for IE in Modern UI)
-    HINSTANCE user32Dll = LoadLibrary(L"user32.dll");
+    Windows_Module_Handle user32Dll(LoadLibrary(L"user32.dll"));
     if (!user32Dll) return true;
 
     IsImmersiveDynamicFunc IsImmersiveDynamicCall = (IsImmersiveDynamicFunc)GetProcAddress(user32Dll, "IsImmersiveProcess");
     if (!IsImmersiveDynamicCall) return true;
 
     BOOL retValue = !IsImmersiveDynamicCall(procHandle);
-    CloseHandle(procHandle);
 
     return retValue;
   }
 }
 
 //-------------------------------------------------------
 // creator_process
 //-------------------------------------------------------
 DWORD creator_process( HWND window )
 {
@@ skipping 254 matching lines @@
       if ( ! is_running() )
       {
         return true ;
       }
     }
     // Assert is_running()
   }
   // No control path leaves the for-loop.
 } ;