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Thread: \x output blowing up

\x output blowing up

From
Martijn van Oosterhout
Date:
Hi,

On CVS tip, whenever I do \x output, it dies with an internal error in
glibc on free. If you run it under valgrind, it complains about these
lines of code:

700                {
701                        char *my_cell = pg_local_malloc(cell_w[i] + 1);
702
703 [Inv write 1 byte]     strcpy(my_cell, *ptr);
704                        if (opt_align[i % col_count] == 'r' && opt_numeric_locale)
705                            format_numeric_locale(my_cell);
706                        if (opt_border < 2)
707                                fprintf(fout, "%s\n", my_cell);
708                        else
709 [Inv read 1 byte]              fprintf(fout, "%-s%*s |\n", my_cell, dwidth - cell_w[i], "");
710                        free(my_cell);
711                }

Now, apart from the fact that the cell width != strlen in multibyte
encodings, there must be something else because this is just "select *
from pg_proc" and there are no multiple characters there AFAIK. I can't
see it though.

Hope this helps,
--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.

Re: \x output blowing up

From
Martijn van Oosterhout
Date:
On Sat, Sep 24, 2005 at 11:45:08PM +0200, Martijn van Oosterhout wrote:
> Hi,
>
> On CVS tip, whenever I do \x output, it dies with an internal error in
> glibc on free. If you run it under valgrind, it complains about these
> lines of code:

<snip>

Ok, I worked out the direct cause, pg_wcswidth only returns the length
upto the first newline and the line it breaks on is the multiline
definition in "_pg_expandarray".

The quick fix should be to only allocate memory if it's going to call
format_numeric_locale(), since then you know it's a number. It makes
the code slightly more convoluated but it should be slightly more
efficient.

I actually have a working psql that handles and displays newlines
properly, but it's too late for 8.1. It fixes all these issues
properly.

Have a nice day,
--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.

Re: \x output blowing up

From
Bruce Momjian
Date:
Well, it seems we are going to have to fix it somehow for 8.1.  It is
not crashing here so I can't work up a patch.  Can you submit a minimal
fix for 8.1?  Thanks.

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

Martijn van Oosterhout wrote:
-- Start of PGP signed section.
> On Sat, Sep 24, 2005 at 11:45:08PM +0200, Martijn van Oosterhout wrote:
> > Hi,
> > 
> > On CVS tip, whenever I do \x output, it dies with an internal error in
> > glibc on free. If you run it under valgrind, it complains about these
> > lines of code:
> 
> <snip>
> 
> Ok, I worked out the direct cause, pg_wcswidth only returns the length
> upto the first newline and the line it breaks on is the multiline
> definition in "_pg_expandarray".
> 
> The quick fix should be to only allocate memory if it's going to call
> format_numeric_locale(), since then you know it's a number. It makes
> the code slightly more convoluated but it should be slightly more
> efficient.
> 
> I actually have a working psql that handles and displays newlines
> properly, but it's too late for 8.1. It fixes all these issues
> properly.
> 
> Have a nice day,
> -- 
> Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> > Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> > tool for doing 5% of the work and then sitting around waiting for someone
> > else to do the other 95% so you can sue them.
-- End of PGP section, PGP failed!

--  Bruce Momjian                        |  http://candle.pha.pa.us pgman@candle.pha.pa.us               |  (610)
359-1001+  If your life is a hard drive,     |  13 Roberts Road +  Christ can be your backup.        |  Newtown Square,
Pennsylvania19073

Re: \x output blowing up

From
Martijn van Oosterhout
Date:
On Sat, Sep 24, 2005 at 07:18:16PM -0400, Bruce Momjian wrote:
>
> Well, it seems we are going to have to fix it somehow for 8.1.  It is
> not crashing here so I can't work up a patch.  Can you submit a minimal
> fix for 8.1?  Thanks.

Ah, it would only happen if your encoding was UTF-8 since that's the
only case psql handles differently. I've attached a patch which fixes
it. With a bit more rearrangement you could probably simplify it a bit
but this works.

Have a nice day,
--
Martijn van Oosterhout   <kleptog@svana.org>   http://svana.org/kleptog/
> Patent. n. Genius is 5% inspiration and 95% perspiration. A patent is a
> tool for doing 5% of the work and then sitting around waiting for someone
> else to do the other 95% so you can sue them.
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