Re: gawk: Locale-dependant bug with string to floating point conversion

[Aharon Robbins]

Greetings.

Jim's patch is incorrect.  The problem is that gawk needs a strtod()
that DOESN'T convert hexadecimal or other non-decimal numbers.  Having
one that does breaks awk semantics.

The correct fix will be to de-hardcode the '.' in the replacement strtod().

I'll add that to my list for the next patch.

Progress, I guess.  (Time marches on, fruit flies like a banana.)

Thanks,

Arnold

> To: Debian Bug Tracking System <address@hidden>,
>    Michael Mauch <address@hidden>
> Cc: address@hidden, Arnold Robbins <address@hidden>
> Subject: gawk: Locale-dependant bug with string to floating point conversion
> From: Jim Meyering <address@hidden>
> Date: Thu, 29 Apr 2004 10:28:30 +0200
>
> Package: gawk
> Version: 1:3.1.3-3
> Severity: normal
> Tags: patch
>
> This bug was originally reported by Michael Mauch here:
>
>   http://mail.gnu.org/archive/html/bug-gnu-utils/2004-04/msg00060.html
>
> It also affects string-to-floating-point conversions.
> This works fine in the C locale:
>
>   $ LC_ALL=c gawk 'BEGIN {print 0+".1"}'
>   0.1
>
> But not in some other locales (assuming you have them installed):
>
>   $ LC_ALL=af_ZA      gawk 'BEGIN {print 0+".1", 0+",1"}'
>   0 0
>   $ address@hidden gawk 'BEGIN {print 0+".1", 0+",1"}'
>   0 0
>
> With the fix below, it works:
>
>   $ LC_ALL=af_ZA ./gawk 'BEGIN {print 0+".1", 0+",1"}'
>   0 0,1
>
> First, gawk is mistakenly using a replacement strtod function,
> when the libc one would work just fine.
> Then, the replacement function hard-codes `.' as the decimal point.
>
> When running configure, I see this:
>
>   checking for strtod with C89 semantics... no
>
> Gawk's configure-time test for a working strtod seems to be reversed.
> Here's a patch to make gawk use libc's strtod when possible.
>
> Eventually, gawk's replacement strtod should be fixed to honor the
> locale-specified decimal point.
>
> 2004-04-29  Jim Meyering  <address@hidden>
>
>       * strtod.m4 (GAWK_FUNC_STRTOD_C89): Fix reversed test.
>
> --- strtod.m4.~1~     2004-04-29 08:57:29.232172928 +0200
> +++ strtod.m4 2004-04-29 08:57:50.402123674 +0200
> @@ -45,7 +45,7 @@ main ()
>    char *str = "0x345a";
>  
>    d = strtod(str, 0);
> -  if (d == 0)
> +  if (d == 13402)
>       exit (0);
>    else
>       exit (1);
>
>
> -- System Information:
> Debian Release: testing/unstable
>   APT prefers unstable
>   APT policy: (500, 'unstable'), (1, 'experimental')
> Architecture: i386 (i686)
> Kernel: Linux 2.6.5
> Locale: LANG=C, LC_CTYPE=C
>
> Versions of packages gawk depends on:
> ii  libc6                       2.3.2.ds1-12 GNU C Library: Shared libraries 
> an
>
> -- no debconf information
>
>
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