Two debug entries for one local variables, is it a bug in GCC or GDB

[asmwarrior]

  On 2010-7-9 13:58, Nenad Vukicevic wrote:
>  I reported something similar back in January:
>
> http://gcc.gnu.org/ml/gcc/2010-01/msg00054.html
>
> As I recall, GCC creates duplicates.
>
> Nenad 
Thanks for the reply. I also found your message,
This bug has been fixed,see:
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39563
You bug report is related to global variables.

My problem is related to a auto variables. Especially the variable will 
be returned.

Something like:

T foo()
{
     T a;
     T b;
     T c;
     ...
     return b;
}

then, the unreturned variable "a" and "c" works well.
But the returned variable "b" will have two debug information entries.