Changed the handling of Win32 function SetErrorMode to be more correct. The f...

tools/test.py

 #!/usr/bin/env python
 #
 # Copyright 2008 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 399 matching lines @@
     pass
   return prev_error_mode
   
 def RunProcess(context, timeout, args, **rest):
   if context.verbose: print "#", " ".join(args)
   popen_args = args
   prev_error_mode = SEM_INVALID_VALUE;
   if utils.IsWindows():
     popen_args = '"' + subprocess.list2cmdline(args) + '"'
     if context.suppress_dialogs:
-      # Try to change the error mode to avoid dialogs on fatal errors.
-      Win32SetErrorMode(SEM_NOGPFAULTERRORBOX)
+      # Try to change the error mode to avoid dialogs on fatal errors. Don't
+      # touch any existing error mode flags by merging the existing error mode.
+      # See http://blogs.msdn.com/oldnewthing/archive/2004/07/27/198410.aspx.
+      error_mode = SEM_NOGPFAULTERRORBOX;
+      prev_error_mode = Win32SetErrorMode(error_mode);
+      Win32SetErrorMode(error_mode | prev_error_mode);
   process = subprocess.Popen(
     shell = utils.IsWindows(),
     args = popen_args,
     **rest
   )
   if utils.IsWindows() and context.suppress_dialogs and prev_error_mode != SEM_INVALID_VALUE:
     Win32SetErrorMode(prev_error_mode)
   # Compute the end time - if the process crosses this limit we
   # consider it timed out.
   if timeout is None: end_time = None
@@ skipping 869 matching lines @@
     for entry in timed_tests[:20]:
       t = FormatTime(entry.duration)
       sys.stderr.write("%4i (%s) %s\n" % (index, t, entry.GetLabel()))
       index += 1
 
   return result
 
 
 if __name__ == '__main__':
   sys.exit(Main())