Issue #1686 - Kill iexplore.exe and AdblockplusEngine.exe processes from the installer

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"
@@ skipping 260 matching lines @@
     case 3 :
       {
         /*
         * Send WM_CLOSE to every admissible window.
         */
         send_message m( WM_CLOSE, 0, 0 ) ;
         iterate_our_windows( m ) ;
       }
       break ;
 
-    default :
+    case 4:
       /*
-      * We're out of ways to try to shut down.
+      * We're out of ways to try to shut down. Oh well. Take cover. It gets violent here.

[Eric, 2015/03/20 08:53:16]

Should restore the first half of the comment to its original location.

       */
-      return false ;
+      for (auto it = pid_set.begin(); it != pid_set.end(); ++it)
+      {
+        HANDLE tmpHandle = OpenProcess(PROCESS_TERMINATE, FALSE, *it);
+        if (!tmpHandle) continue;
+        Windows_Handle procHandle(tmpHandle);
+        TerminateProcess(tmpHandle, 0);

[Eric, 2015/03/20 08:53:16]

Given how unreliable it's turning out to be to shut down IE, it would be a good
idea to log the error code associated with a failure of TerminateProcess() here.
That would mean changing the signature of ShutDown() to pass a log instance. Had
I realized what trouble this would be, I would have done that the first time.

The error that would most useful to log here would be absence of the
PROCESS_TERMINATE access right. In practice, that would require running an MSI
as administrator, but if that's the trick to make it work, there's no
information coming out of a failure here that would even provide a clue toward
that.

[sergei, 2015/04/02 08:04:09]

Merely want to add that MSI is already configured to run with elevated
privileges and running MSI as Administrator still could be not enough to
terminate the process.

[sergei, 2015/04/02 08:04:09]

As well as it would be good to log the state to better understand which part
failed to shut down IE.

[Eric, 2015/05/14 15:09:25]

The process 'msiexec.exe' runs with elevated privileges. Custom actions, such as
the present code, run in a separate container process and do not necessarily
have the same privileges.

There are ways of doing that, but we're not using them. Given that the whole
purpose of this CA is to avoid an annoyance (rebooting), it's not clear to me
that forcibly closing IE is worth it; the cure (side-effects of premature
termination of IE) may be worse than the disease (the annoyance of rebooting).

+      }
+      break;
+
+    default:
+      return false;
     }
 
     /*
     * Wait loop.
     */
     for ( unsigned int j = 0 ; j < 50 ; ++ j )
     {
-      std::this_thread::sleep_for( std::chrono::milliseconds( 100 ) ) ;
+      std::this_thread::sleep_for( std::chrono::milliseconds( 30 ) ) ;
       Refresh() ;
       if ( ! IsRunning() )
       {
         return true ;
       }
     }
     // Assert is_running()
   }
   // No control path leaves the for-loop.
 } ;