http://d.puremagic.com/issues/show_bug.cgi?id=2065

           Summary: Return value of std.file.exists() is inverted.
           Product: D
           Version: 2.014
          Platform: PC
               URL: http://dsource.org/projects/phobos/changeset/683
        OS/Version: Windows
            Status: NEW
          Severity: normal
          Priority: P2
         Component: Phobos
        AssignedTo: andrei@metalanguage.com
        ReportedBy: torhu@yahoo.com


In r683, the Windows version of this function is changed into return the wrong value.

The correct return statement would be "return result != 0xFFFFFFFF;"

The relevant docs: http://msdn.microsoft.com/en-us/library/aa915578.aspx


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=2065


andrei@metalanguage.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED




------- Comment #1 from andrei@metalanguage.com  2008-05-03 11:25 -------
(In reply to comment #0)
> In r683, the Windows version of this function is changed into return the wrong value.
> 
> The correct return statement would be "return result != 0xFFFFFFFF;"
> 
> The relevant docs: http://msdn.microsoft.com/en-us/library/aa915578.aspx

Ouch. How did that ever go through? The fix will go into the next release. Thanks!


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=2065





------- Comment #2 from bugzilla@digitalmars.com  2008-05-12 15:47 -------
I'm having a hard time seeing how:

return (result == 0xFFFFFFFF) ? 0 : 1;

is different from:

return result != 0xFFFFFFFF;


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=2065





------- Comment #3 from andrei@metalanguage.com  2008-05-12 15:55 -------
(In reply to comment #2)
> I'm having a hard time seeing how:
> 
> return (result == 0xFFFFFFFF) ? 0 : 1;
> 
> is different from:
> 
> return result != 0xFFFFFFFF;

I see that revision 682 and before had:

return (result == 0xFFFFFFFF) ? 0 : 1;

which is correct. In revision 683 I fixed exists to return bool instead of int (just like $DEITY intended it) and in the process I introduced the bug:

return result == 0xFFFFFFFF;

The one I recently checked into dsource has:

return result != 0xFFFFFFFF;

which should fix the bug. Sorry for the mistake.


-- 

On 12/05/2008, d-bugmail@puremagic.com <d-bugmail@puremagic.com> wrote:
>  I'm having a hard time seeing how:
>
>  return (result == 0xFFFFFFFF) ? 0 : 1;
>
>  is different from:
>
>  return result != 0xFFFFFFFF;

It's certainly conceptually different. The first one returns an int, with possible values 0 and 1. The second one returns a bool with possible values false and true.

http://d.puremagic.com/issues/show_bug.cgi?id=2065





------- Comment #5 from andrei@metalanguage.com  2008-05-12 16:41 -------
(In reply to comment #4)
> On 12/05/2008, d-bugmail@puremagic.com <d-bugmail@puremagic.com> wrote:
> >  I'm having a hard time seeing how:
> >
> >  return (result == 0xFFFFFFFF) ? 0 : 1;
> >
> >  is different from:
> >
> >  return result != 0xFFFFFFFF;
> 
> It's certainly conceptually different. The first one returns an int, with possible values 0 and 1. The second one returns a bool with possible values false and true.
> 

In fact it seems the constants 0 and 1 are implicitly convertible to bool but no other integral values, which is a nice touch. I tried this program and was pleasantly surprised:

void main()
{
    bool a = 0;
    bool b = 1;
    bool c = 2;
}

It does not compile, but it does if you remove the definition of c. This is the kind of smarts that I'd like to extend to inferring data ranges and signedness.


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=2065


andrei@metalanguage.com changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|                            |FIXED




------- Comment #6 from andrei@metalanguage.com  2008-05-17 11:24 -------
Fixed in 2.014.


-- 

http://d.puremagic.com/issues/show_bug.cgi?id=2065





------- Comment #7 from bugzilla@digitalmars.com  2008-05-22 05:03 -------
Fixed dmd 1.030 and 2.014


--