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User-Agent: Mozilla/4.77 [en] (X11; U; Linux 2.4.2-2 i586)

Description of problem:
While all floating-point conversions work for scanning "inf" and "infinity"
(regardless of case), they all fail for "+inf" and "-inf" (and "+infinity"
and "-infinity", regardless of case).

The C standard requires that %a, %e, %f, and %g match an optionally signed
floating-point number, infinity, or NaN, in the same format expected for
the strtod() function.


How reproducible:
Always

Steps to Reproduce:
Compile and run the following program:

#include <stdio.h>
#define __USE_ISOC99 1
#include <math.h>
#include <stdlib.h>

const char *test_strings[] = {
  "inf", "INF", "infinity", "INFINITY", "Inf", "iNfInItY",
  "+inf", "+INF", "+infinity", "+INFINITY", "+Inf", "+InFiNiTy",
  "-inf", "-INF", "-infinity", "-INFINITY", "-Inf", "-INFinitY",
};

const char *test_formats[] = { "%a%n", "%e%n", "%f%n", "%g%n",
			       "%A%n", "%E%n", "%F%n", "%G%n" };

int
main ()
{
  int i, j, l, n;
  float f;
  char *endp;

  for (i = 0; i < sizeof (test_strings) / sizeof (test_strings[0]); i++) {
    f = strtof (test_strings[i], &endp);
    if (*endp)
      fprintf (stderr, "Error: strtof(\"%s\") scanned %d characters\n",
	       test_strings[i], endp - &test_strings[i][0]);
    else if (!isinf(f))
      fprintf (stderr, "Error: strtof(\"%s\") returned %g\n",
	       test_strings[i], f);
    else
      fprintf (stderr, "strtof(\"%s\") passed\n", test_strings[i]);

    for (j = 0; j < sizeof (test_formats) / sizeof (test_formats[0]); j++)
{
      f = 0.0F;
      l = -1;
      n = sscanf (test_strings[i], test_formats[j], &f, &l);
      if (n < 1)
	fprintf (stderr, "Error: sscanf(\"%s\",\"%s\",&f) returned %d\n",
		 test_strings[i], test_formats[j], n);
      if ((l >= 0) && test_strings[i][l])
	fprintf (stderr,
		 "Error: sscanf(\"%s\",\"%s\",&f) scanned %d characters\n",
		 test_strings[i], test_formats[j], l);
      if (!isinf (f) && ((n >= 1) || (f != 0.0F)))
	fprintf (stderr, "Error: sscanf(\"%s\",\"%s\",&f) stored %g\n",
		 test_strings[i], test_formats[j], f);
      if ((n >= 1) && isinf (f))
	fprintf (stderr, "sscanf(\"%s\",\"%s\",&f) passed\n",
		 test_strings[i], test_formats[j]);
    }
  }
}


Actual Results:  (long list; here's the summary: 57 tests passed, 105
errors reported)

strtof("inf") passed
sscanf("inf","%a%n",&f) passed
...
sscanf("iNfInItY","%G%n",&f) passed
strtof("+inf") passed
Error: sscanf("+inf","%a%n",&f) returned 0
...
Error: sscanf("-Inf","%G%n",&f) returned 0
Error: strtof("-INFinitY") scanned 4 characters
Error: sscanf("-INFinitY","%a%n",&f) returned 0


Expected Results:  All 162 tests should pass


Additional info:

c.f. WG14/N869 7.19.6.2#12&14, 7.20.1.3#3-4