[Win32utils-devel] [ win32utils-Bugs-4598 ] possible wrong condition

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Bugs item #4598, was opened at 2006-05-29 08:20
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http://rubyforge.org/tracker/?func=detail&atid=411&aid=4598&group_id=85

Category: win32-eventlog
Group: None
Status: Open
Resolution: Accepted
Priority: 3
Submitted By: Nobody (None)
Assigned to: Daniel Berger (djberg96)
Summary: possible wrong condition

Initial Comment:
Is this condition right?
(eventlog.rb, line 494

     if flags | EVENTLOG_SEEK_READ > 0
        offset = buf[8,4].unpack('L').first + 1
     end

To me it seems that it is always true as E_S_R == 2.
Maybe this is how it was meant:

     unless flags & EVENTLOG_SEEK_READ > 0

I haven't understood the rest of the code, so I'm not sure about the solution.

Jano Svitok

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>Comment By: Daniel Berger (djberg96)
Date: 2006-06-18 10:07

Message:
Here was the final patch, applied to CVS:

if flags & EVENTLOG_BACKWARDS_READ > 0
   offset = buf[8,4].unpack('L').first - 1
else
   offset = buf[8,4].unpack('L').first + 1
end

This will be in the next release.

Dan

----------------------------------------------------------------------

Comment By: Daniel Berger (djberg96)
Date: 2006-05-29 10:38

Message:
Not only is the code wrong, some testing revealed that code was the source of another bug.  Specifically, a seek + backwards read would loop infinitely.

I believe this is the proper code:

if flags & EVENTLOG_SEEK_READ > 0
   if flags & EVENTLOG_FORWARDS_READ > 0
      offset = buf[8,4].unpack('L').first + 1
   else
      offset = buf[8,4].unpack('L').first - 1
   end
end

I'll add some more tests for this.  Many thanks for the report!

- Dan

----------------------------------------------------------------------

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