/* $Id: snprintf.c 10396 2020-11-12 20:19:41Z iulius $
 *
 * Replacement for a missing snprintf or vsnprintf.
 *
 * The following implementation of snprintf was taken mostly verbatim from
 * <http://www.fiction.net/blong/programs/>; it is the version of snprintf
 * used in Mutt.  A possibly newer version is used in wget, found at
 * <https://github.com/wertarbyte/wget/blob/master/src/snprintf.c>.
 *
 * Please do not reformat or otherwise change this file more than necessary so
 * that later merges with the original source are easy.  Bug fixes and
 * improvements should be sent back to the original author.
 *
 * The canonical version of this file was maintained (until 2020) in the
 * rra-c-util package, which can be found at
 * <https://www.eyrie.org/~eagle/software/rra-c-util/>.
 */

/*
 * If we're running the test suite, rename snprintf and vsnprintf to avoid
 * conflicts with the system version.
 */
#if TESTING
# undef snprintf
# undef vsnprintf
# define snprintf test_snprintf
# define vsnprintf test_vsnprintf
#endif

/*
 * __attribute__ is available in gcc 2.5 and later, but only with gcc 2.7
 * could you use the __format__ form of the attributes, which is what we use
 * (to avoid confusion with other macros).
 */
#ifndef __attribute__
#    if __GNUC__ < 2 || (__GNUC__ == 2 && __GNUC_MINOR__ < 7)
#        define __attribute__(spec) /* empty */
#    endif
#endif

/*
 * Older Clang doesn't support __attribute__((fallthrough)) properly and
 * complains about the empty statement that it is decorating.  Suppress that
 * warning.  Also suppress warnings about unknown attributes to handle older
 * Clang versions.
 */
#if !defined(__attribute__) && (defined(__llvm__) || defined(__clang__))
#    pragma GCC diagnostic ignored "-Wattributes"
#    pragma GCC diagnostic ignored "-Wmissing-declarations"
#endif

/* Specific to rra-c-util, but only when debugging is enabled. */
#ifdef DEBUG_SNPRINTF
# include "inn/messages.h"
#endif

/*
 * Copyright Patrick Powell 1995
 * This code is based on code written by Patrick Powell (papowell@astart.com)
 * It may be used for any purpose as long as this notice remains intact
 * on all source code distributions
 *
 * There is no SPDX-License-Identifier registered for this license.
 */

/**************************************************************
 * Original:
 * Patrick Powell Tue Apr 11 09:48:21 PDT 1995
 * A bombproof version of doprnt (dopr) included.
 * Sigh.  This sort of thing is always nasty do deal with.  Note that
 * the version here does not include floating point...
 *
 * snprintf() is used instead of sprintf() as it does limit checks
 * for string length.  This covers a nasty loophole.
 *
 * The other functions are there to prevent NULL pointers from
 * causing nast effects.
 *
 * More Recently:
 *  Brandon Long <blong@fiction.net> 9/15/96 for mutt 0.43
 *  This was ugly.  It is still ugly.  I opted out of floating point
 *  numbers, but the formatter understands just about everything
 *  from the normal C string format, at least as far as I can tell from
 *  the Solaris 2.5 printf(3S) man page.
 *
 *  Brandon Long <blong@fiction.net> 10/22/97 for mutt 0.87.1
 *    Ok, added some minimal floating point support, which means this
 *    probably requires libm on most operating systems.  Don't yet
 *    support the exponent (e,E) and sigfig (g,G).  Also, fmtint()
 *    was pretty badly broken, it just wasn't being exercised in ways
 *    which showed it, so that's been fixed.  Also, formatted the code
 *    to mutt conventions, and removed dead code left over from the
 *    original.  Also, there is now a builtin-test, just compile with:
 *           gcc -DTEST_SNPRINTF -o snprintf snprintf.c -lm
 *    and run snprintf for results.
 * 
 *  Thomas Roessler <roessler@guug.de> 01/27/98 for mutt 0.89i
 *    The PGP code was using unsigned hexadecimal formats. 
 *    Unfortunately, unsigned formats simply didn't work.
 *
 *  Michael Elkins <me@cs.hmc.edu> 03/05/98 for mutt 0.90.8
 *    The original code assumed that both snprintf() and vsnprintf() were
 *    missing.  Some systems only have snprintf() but not vsnprintf(), so
 *    the code is now broken down under HAVE_SNPRINTF and HAVE_VSNPRINTF.
 *
 *  Andrew Tridgell (tridge@samba.org) Oct 1998
 *    fixed handling of %.0f
 *    added test for HAVE_LONG_DOUBLE
 *
 *  Russ Allbery <eagle@eyrie.org> 2000-08-26
 *    fixed return value to comply with C99
 *    fixed handling of snprintf(NULL, ...)
 *    added explicit casts for double to long long int conversion
 *    fixed various warnings with GCC 7
 *    fixed various warnings with Clang
 *
 *  Hrvoje Niksic <hniksic@xemacs.org> 2000-11-04
 *    include <config.h> instead of "config.h".
 *    moved TEST_SNPRINTF stuff out of HAVE_SNPRINTF ifdef.
 *    include <stdio.h> for NULL.
 *    added support and test cases for long long.
 *    don't declare argument types to (v)snprintf if stdarg is not used.
 *    use int instead of short int as 2nd arg to va_arg.
 *
 *  alexk (INN) 2002-08-21
 *    use LLONG in fmtfp to handle more characters during floating
 *    point conversion.
 *
 *  herb (Samba) 2002-12-19
 *    actually print args for %g and %e
 *
 *  Hrvoje Niksic <hniksic@xemacs.org> 2005-04-15
 *    use the PARAMS macro to handle prototypes.
 *    write function definitions in the ansi2knr-friendly way.
 *    if string precision is specified, don't read VALUE past it.
 *    fix bug in fmtfp that caused 0.01 to be printed as 0.1.
 *    don't include <ctype.h> because none of it is used.
 *    interpret precision as number of significant digits with %g
 *    omit trailing decimal zeros with %g
 *
 **************************************************************/

#include "config.h"

#include <string.h>
#include <ctype.h>
#include <sys/types.h>

#ifndef NULL
# define NULL 0
#endif

/* varargs declarations: */

#include <stdarg.h>

/* Assume all compilers support long double, per Autoconf documentation. */
#define LDOUBLE long double

#ifdef HAVE_LONG_LONG_INT
# define LLONG long long
#else
# define LLONG long
#endif

int snprintf (char *str, size_t count, const char *fmt, ...);
int vsnprintf (char *str, size_t count, const char *fmt, va_list arg);

static int dopr (char *buffer, size_t maxlen, const char *format, 
                 va_list args);
static int fmtstr (char *buffer, size_t *currlen, size_t maxlen,
		   const char *value, int flags, int min, int max);
static int fmtint (char *buffer, size_t *currlen, size_t maxlen,
		   LLONG value, int base, int min, int max, int flags);
static int fmtfp (char *buffer, size_t *currlen, size_t maxlen,
		  LDOUBLE fvalue, int min, int max, int flags);
static int dopr_outch (char *buffer, size_t *currlen, size_t maxlen, char c );

/*
 * dopr(): poor man's version of doprintf
 */

/* format read states */
#define DP_S_DEFAULT 0
#define DP_S_FLAGS   1
#define DP_S_MIN     2
#define DP_S_DOT     3
#define DP_S_MAX     4
#define DP_S_MOD     5
#define DP_S_MOD_L   6
#define DP_S_CONV    7
#define DP_S_DONE    8

/* format flags - Bits */
#define DP_F_MINUS 	(1 << 0)
#define DP_F_PLUS  	(1 << 1)
#define DP_F_SPACE 	(1 << 2)
#define DP_F_NUM   	(1 << 3)
#define DP_F_ZERO  	(1 << 4)
#define DP_F_UP    	(1 << 5)
#define DP_F_UNSIGNED 	(1 << 6)
#define DP_F_FP_G 	(1 << 7)

/* Conversion Flags */
#define DP_C_SHORT   1
#define DP_C_LONG    2
#define DP_C_LLONG   3
#define DP_C_LDOUBLE 4

#define char_to_int(p) (p - '0')
#define MAX(p,q) ((p >= q) ? p : q)
#define MIN(p,q) ((p <= q) ? p : q)

static int dopr (char *buffer, size_t maxlen, const char *format, va_list args)
{
  char ch;
  LLONG value;
  LDOUBLE fvalue;
  char *strvalue;
  int min;
  int max;
  unsigned int state;
  int flags;
  int cflags;
  int total;
  size_t currlen;
  
  state = DP_S_DEFAULT;
  currlen = flags = cflags = min = 0;
  max = -1;
  ch = *format++;
  total = 0;

  while (state != DP_S_DONE)
  {
    if (ch == '\0')
      state = DP_S_DONE;

    switch(state) 
    {
    case DP_S_DEFAULT:
      if (ch == '%') 
	state = DP_S_FLAGS;
      else 
	total += dopr_outch (buffer, &currlen, maxlen, ch);
      ch = *format++;
      break;
    case DP_S_FLAGS:
      switch (ch) 
      {
      case '-':
	flags |= DP_F_MINUS;
        ch = *format++;
	break;
      case '+':
	flags |= DP_F_PLUS;
        ch = *format++;
	break;
      case ' ':
	flags |= DP_F_SPACE;
        ch = *format++;
	break;
      case '#':
	flags |= DP_F_NUM;
        ch = *format++;
	break;
      case '0':
	flags |= DP_F_ZERO;
        ch = *format++;
	break;
      default:
	state = DP_S_MIN;
	break;
      }
      break;
    case DP_S_MIN:
      if ('0' <= ch && ch <= '9') 
      {
	min = 10*min + char_to_int (ch);
	ch = *format++;
      } 
      else if (ch == '*') 
      {
	min = va_arg (args, int);
	ch = *format++;
	state = DP_S_DOT;
      } 
      else 
	state = DP_S_DOT;
      break;
    case DP_S_DOT:
      if (ch == '.') 
      {
	state = DP_S_MAX;
	ch = *format++;
      } 
      else 
	state = DP_S_MOD;
      break;
    case DP_S_MAX:
      if ('0' <= ch && ch <= '9')
      {
	if (max < 0)
	  max = 0;
	max = 10*max + char_to_int (ch);
	ch = *format++;
      } 
      else if (ch == '*') 
      {
	max = va_arg (args, int);
	ch = *format++;
	state = DP_S_MOD;
      } 
      else 
	state = DP_S_MOD;
      break;
    case DP_S_MOD:
      switch (ch) 
      {
      case 'h':
	cflags = DP_C_SHORT;
	ch = *format++;
	break;
      case 'l':
	cflags = DP_C_LONG;
	ch = *format++;
	break;
      case 'L':
	cflags = DP_C_LDOUBLE;
	ch = *format++;
	break;
      default:
	break;
      }
      if (cflags != DP_C_LONG)
        state = DP_S_CONV;
      else
        state = DP_S_MOD_L;
      break;
    case DP_S_MOD_L:
      switch (ch)
      {
      case 'l':
        cflags = DP_C_LLONG;
        ch = *format++;
        break;
      default:
        break;
      }
      state = DP_S_CONV;
      break;
    case DP_S_CONV:
      switch (ch) 
      {
      case 'd':
      case 'i':
	if (cflags == DP_C_SHORT) 
	  value = (short int) va_arg (args, int);
	else if (cflags == DP_C_LONG)
	  value = va_arg (args, long int);
        else if (cflags == DP_C_LLONG)
          value = va_arg (args, LLONG);
	else
	  value = va_arg (args, int);
	total += fmtint (buffer, &currlen, maxlen, value, 10, min, max, flags);
	break;
      case 'o':
	flags |= DP_F_UNSIGNED;
	if (cflags == DP_C_SHORT)
	  value = (unsigned short int) va_arg (args, unsigned int);
	else if (cflags == DP_C_LONG)
	  value = va_arg (args, unsigned long int);
        else if (cflags == DP_C_LLONG)
          value = va_arg (args, unsigned LLONG);
	else
	  value = va_arg (args, unsigned int);
	total += fmtint (buffer, &currlen, maxlen, value, 8, min, max, flags);
	break;
      case 'u':
	flags |= DP_F_UNSIGNED;
	if (cflags == DP_C_SHORT)
	  value = (unsigned short int) va_arg (args, unsigned int);
	else if (cflags == DP_C_LONG)
	  value = va_arg (args, unsigned long int);
        else if (cflags == DP_C_LLONG)
          value = va_arg (args, unsigned LLONG);
	else
	  value = va_arg (args, unsigned int);
	total += fmtint (buffer, &currlen, maxlen, value, 10, min, max, flags);
	break;
      case 'X':
	flags |= DP_F_UP;
        __attribute__((fallthrough));
        /* fall through */
      case 'x':
	flags |= DP_F_UNSIGNED;
	if (cflags == DP_C_SHORT)
	  value = (unsigned short int) va_arg (args, unsigned int);
	else if (cflags == DP_C_LONG)
	  value = va_arg (args, unsigned long int);
        else if (cflags == DP_C_LLONG)
          value = va_arg (args, unsigned LLONG);
	else
	  value = va_arg (args, unsigned int);
	total += fmtint (buffer, &currlen, maxlen, value, 16, min, max, flags);
	break;
      case 'f':
	if (cflags == DP_C_LDOUBLE)
	  fvalue = va_arg (args, LDOUBLE);
	else
	  fvalue = (LDOUBLE) va_arg (args, double);
	total += fmtfp (buffer, &currlen, maxlen, fvalue, min, max, flags);
	break;
      case 'E':
	flags |= DP_F_UP;
        __attribute__((fallthrough));
        /* fall through */
      case 'e':
	if (cflags == DP_C_LDOUBLE)
	  fvalue = va_arg (args, LDOUBLE);
	else
	  fvalue = (LDOUBLE) va_arg (args, double);
        total += fmtfp (buffer, &currlen, maxlen, fvalue, min, max, flags);
	break;
      case 'G':
	flags |= DP_F_UP;
        __attribute__((fallthrough));
        /* fall through */
      case 'g':
        flags |= DP_F_FP_G;
	if (cflags == DP_C_LDOUBLE)
	  fvalue = va_arg (args, LDOUBLE);
	else
	  fvalue = (LDOUBLE) va_arg (args, double);
	if (max == 0)
	  /* C99 says: if precision [for %g] is zero, it is taken as one */
	  max = 1;
	total += fmtfp (buffer, &currlen, maxlen, fvalue, min, max, flags);
	break;
      case 'c':
	total += dopr_outch (buffer, &currlen, maxlen,
			     (char) va_arg (args, int));
	break;
      case 's':
	strvalue = va_arg (args, char *);
	total += fmtstr (buffer, &currlen, maxlen, strvalue, flags, min, max);
	break;
      case 'p':
	strvalue = va_arg (args, void *);
	total += fmtint (buffer, &currlen, maxlen, (long) strvalue, 16, min,
                         max, flags);
	break;
      case 'n':
	if (cflags == DP_C_SHORT) 
	{
	  short int *num;
	  num = va_arg (args, short int *);
	  *num = (short) currlen;
        } 
	else if (cflags == DP_C_LONG) 
	{
	  long int *num;
	  num = va_arg (args, long int *);
	  *num = currlen;
        }
        else if (cflags == DP_C_LLONG) 
        {
          LLONG *num;
          num = va_arg (args, LLONG *);
          *num = currlen;
        } 
	else 
	{
	  int *num;
	  num = va_arg (args, int *);
	  *num = (int) currlen;
        }
	break;
      case '%':
	total += dopr_outch (buffer, &currlen, maxlen, ch);
	break;
      case 'w':
	/* not supported yet, treat as next char */
	format++;
	break;
      default:
	/* Unknown, skip */
	break;
      }
      ch = *format++;
      state = DP_S_DEFAULT;
      flags = cflags = min = 0;
      max = -1;
      break;
    case DP_S_DONE:
      break;
    default:
      /* hmm? */
      break; /* some picky compilers need this */
    }
  }
  if (buffer != NULL)
  {
    if (currlen < maxlen - 1) 
      buffer[currlen] = '\0';
    else 
      buffer[maxlen - 1] = '\0';
  }
  return total;
}

static int fmtstr (char *buffer, size_t *currlen, size_t maxlen,
                   const char *value, int flags, int min, int max)
{
  int padlen, strln;     /* amount to pad */
  int cnt = 0;
  int total = 0;
  
  if (value == 0)
  {
    value = "(null)";
  }

  if (max < 0)
    strln = (int) strlen (value);
  else
    /* When precision is specified, don't read VALUE past precision. */
    /*strln = strnlen (value, max);*/
    for (strln = 0; strln < max && value[strln]; ++strln);
  padlen = min - strln;
  if (padlen < 0) 
    padlen = 0;
  if (flags & DP_F_MINUS) 
    padlen = -padlen; /* Left Justify */

  while (padlen > 0)
  {
    total += dopr_outch (buffer, currlen, maxlen, ' ');
    --padlen;
  }
  while (*value && ((max < 0) || (cnt < max)))
  {
    total += dopr_outch (buffer, currlen, maxlen, *value++);
    ++cnt;
  }
  while (padlen < 0)
  {
    total += dopr_outch (buffer, currlen, maxlen, ' ');
    ++padlen;
  }
  return total;
}

/* Have to handle DP_F_NUM (ie 0x and 0 alternates) */

static int fmtint (char *buffer, size_t *currlen, size_t maxlen,
		   LLONG value, int base, int min, int max, int flags)
{
  char signvalue = 0;
  unsigned LLONG uvalue;
  char convert[24];
  unsigned int place = 0;
  int spadlen = 0; /* amount to space pad */
  int zpadlen = 0; /* amount to zero pad */
  const char *digits;
  int total = 0;
  
  if (max < 0)
    max = 0;

  uvalue = value;

  if(!(flags & DP_F_UNSIGNED))
  {
    if( value < 0 ) {
      signvalue = '-';
      uvalue = -value;
    }
    else
      if (flags & DP_F_PLUS)  /* Do a sign (+/i) */
	signvalue = '+';
    else
      if (flags & DP_F_SPACE)
	signvalue = ' ';
  }
  
  if (flags & DP_F_UP)
    /* Should characters be upper case? */
    digits = "0123456789ABCDEF";
  else
    digits = "0123456789abcdef";

  do {
    convert[place++] = digits[uvalue % (unsigned)base];
    uvalue = (uvalue / (unsigned)base );
  } while(uvalue && (place < sizeof (convert)));
  if (place == sizeof (convert)) place--;
  convert[place] = 0;

  zpadlen = max - place;
  spadlen = min - MAX ((unsigned int)max, place) - (signvalue ? 1 : 0);
  if (zpadlen < 0) zpadlen = 0;
  if (spadlen < 0) spadlen = 0;
  if (flags & DP_F_ZERO)
  {
    zpadlen = MAX(zpadlen, spadlen);
    spadlen = 0;
  }
  if (flags & DP_F_MINUS) 
    spadlen = -spadlen; /* Left Justifty */

#ifdef DEBUG_SNPRINTF
  debug ("zpad: %d, spad: %d, min: %d, max: %d, place: %u\n",
         zpadlen, spadlen, min, max, place);
#endif

  /* Spaces */
  while (spadlen > 0) 
  {
    total += dopr_outch (buffer, currlen, maxlen, ' ');
    --spadlen;
  }

  /* Sign */
  if (signvalue) 
    total += dopr_outch (buffer, currlen, maxlen, signvalue);

  /* Zeros */
  if (zpadlen > 0) 
  {
    while (zpadlen > 0)
    {
      total += dopr_outch (buffer, currlen, maxlen, '0');
      --zpadlen;
    }
  }

  /* Digits */
  while (place > 0) 
    total += dopr_outch (buffer, currlen, maxlen, convert[--place]);
  
  /* Left Justified spaces */
  while (spadlen < 0) {
    total += dopr_outch (buffer, currlen, maxlen, ' ');
    ++spadlen;
  }

  return total;
}

static LDOUBLE abs_val (LDOUBLE value)
{
  LDOUBLE result = value;

  if (value < 0)
    result = -value;

  return result;
}

static LLONG pow10_int (unsigned int exp)
{
  LDOUBLE result = 1;

  while (exp)
  {
    result *= 10;
    exp--;
  }
  
  return (LLONG) result;
}

static LLONG round_int (LDOUBLE value)
{
  LLONG intpart;

  intpart = (LLONG) value;
  value = value - intpart;
  if (value >= (LDOUBLE) 0.5)
    intpart++;

  return intpart;
}

/*
 * GCC 7.1 issues this warning at the point of the function definition header
 * (not in any actual code), and I can't figure out what's triggering it since
 * the comparison form doesn't appear anywhere in this code.  Since this is
 * rarely-used portability code, suppress the warning.
 */
#pragma GCC diagnostic ignored "-Wstrict-overflow"

static int fmtfp (char *buffer, size_t *currlen, size_t maxlen,
		  LDOUBLE fvalue, int min, int max, int flags)
{
  char signvalue = 0;
  LDOUBLE ufvalue;
  char iconvert[24];
  char fconvert[24];
  size_t iplace = 0;
  size_t fplace = 0;
  long padlen = 0; /* amount to pad */
  long zpadlen = 0; 
  int total = 0;
  LLONG intpart;
  LLONG fracpart;
  LLONG mask10;
  int leadingfrac0s = 0; /* zeroes at the start of fractional part */
  int omitzeros = 0;
  size_t omitcount = 0;
  
  /* 
   * AIX manpage says the default is 0, but Solaris says the default
   * is 6, and sprintf on AIX defaults to 6
   */
  if (max < 0)
    max = 6;

  ufvalue = abs_val (fvalue);

  if (fvalue < 0)
    signvalue = '-';
  else
    if (flags & DP_F_PLUS)  /* Do a sign (+/i) */
      signvalue = '+';
    else
      if (flags & DP_F_SPACE)
	signvalue = ' ';

#if 0
  if (flags & DP_F_UP) caps = 1; /* Should characters be upper case? */
#endif

  intpart = (LLONG) ufvalue;

  /* With %g precision is the number of significant digits, which
     includes the digits in intpart. */
  if (flags & DP_F_FP_G)
    {
      if (intpart != 0)
	{
	  /* For each digit of INTPART, print one less fractional digit. */
	  LLONG temp;
	  for (temp = intpart; temp != 0; temp /= 10)
	    --max;
	  if (max < 0)
	    max = 0;
	}
      else
	{
	  /* For each leading 0 in fractional part, print one more
	     fractional digit. */
	  LDOUBLE temp;
	  if (ufvalue > 0)
	    for (temp = ufvalue; temp < (LDOUBLE) 0.1; temp *= 10)
	      ++max;
	}
    }

  /* C99: trailing zeros are removed from the fractional portion of the
     result unless the # flag is specified */
  if ((flags & DP_F_FP_G) && !(flags & DP_F_NUM))
    omitzeros = 1;

#if SIZEOF_LONG_LONG > 0
# define MAX_DIGITS 18		/* grok more digits with long long */
#else
# define MAX_DIGITS 9		/* just long */
#endif

  /* 
   * Sorry, we only support several digits past the decimal because of
   * our conversion method
   */
  if (max > MAX_DIGITS)
    max = MAX_DIGITS;

  /* Factor of 10 with the needed number of digits, e.g. 1000 for max==3 */
  mask10 = pow10_int (max);

  /* We "cheat" by converting the fractional part to integer by
   * multiplying by a factor of 10
   */
  fracpart = round_int (mask10 * (ufvalue - intpart));

  if (fracpart >= mask10)
  {
    intpart++;
    fracpart -= mask10;
  }
  else if (fracpart != 0)
    /* If fracpart has less digits than the 10* mask, we need to
       manually insert leading 0s.  For example 2.01's fractional part
       requires one leading zero to distinguish it from 2.1. */
    while (fracpart < mask10 / 10)
      {
	++leadingfrac0s;
	mask10 /= 10;
      }

#ifdef DEBUG_SNPRINTF
# ifdef HAVE_LONG_LONG_INT
  debug ("fmtfp: %Lf =? %lld.%lld\n", fvalue, intpart, fracpart);
# else
  debug ("fmtfp: %Lf =? %ld.%ld\n", fvalue, intpart, fracpart);
# endif
#endif

  /* Convert integer part */
  do {
    iconvert[iplace++] = (char) ('0' + (intpart % 10));
    intpart = (intpart / 10);
  } while(intpart && (iplace < sizeof(iconvert)));
  if (iplace == sizeof(iconvert)) iplace--;
  iconvert[iplace] = 0;

  /* Convert fractional part */
  do {
    fconvert[fplace++] = (char) ('0' + (fracpart % 10));
    fracpart = (fracpart / 10);
  } while(fracpart && (fplace < sizeof(fconvert)));
  while (leadingfrac0s-- > 0 && fplace < sizeof(fconvert))
    fconvert[fplace++] = '0';
  if (fplace == sizeof(fconvert)) fplace--;
  fconvert[fplace] = 0;
  if (omitzeros)
    while (omitcount < fplace && fconvert[omitcount] == '0')
      ++omitcount;

  /* -1 for decimal point, another -1 if we are printing a sign */
  padlen = min - iplace - (max - omitcount) - 1 - ((signvalue) ? 1 : 0);
  if (!omitzeros)
    zpadlen = max - fplace;
  if (zpadlen < 0)
    zpadlen = 0;
  if (padlen < 0) 
    padlen = 0;
  if (flags & DP_F_MINUS) 
    padlen = -padlen; /* Left Justifty */

  if ((flags & DP_F_ZERO) && (padlen > 0)) 
  {
    if (signvalue) 
    {
      total += dopr_outch (buffer, currlen, maxlen, signvalue);
      --padlen;
      signvalue = 0;
    }
    while (padlen > 0)
    {
      total += dopr_outch (buffer, currlen, maxlen, '0');
      --padlen;
    }
  }
  while (padlen > 0)
  {
    total += dopr_outch (buffer, currlen, maxlen, ' ');
    --padlen;
  }
  if (signvalue) 
    total += dopr_outch (buffer, currlen, maxlen, signvalue);

  while (iplace > 0) 
    total += dopr_outch (buffer, currlen, maxlen, iconvert[--iplace]);

  /*
   * Decimal point.  This should probably use locale to find the correct
   * char to print out.
   */
  if (max > 0 && (fplace > omitcount || zpadlen > 0))
  {
    total += dopr_outch (buffer, currlen, maxlen, '.');

    while (fplace > omitcount) 
      total += dopr_outch (buffer, currlen, maxlen, fconvert[--fplace]);
  }

  while (zpadlen > 0)
  {
    total += dopr_outch (buffer, currlen, maxlen, '0');
    --zpadlen;
  }

  while (padlen < 0) 
  {
    total += dopr_outch (buffer, currlen, maxlen, ' ');
    ++padlen;
  }

  return total;
}

static int dopr_outch (char *buffer, size_t *currlen, size_t maxlen, char c)
{
  if (*currlen + 1 < maxlen)
    buffer[(*currlen)++] = c;
  return 1;
}

int vsnprintf (char *str, size_t count, const char *fmt, va_list args)
{
  if (str != NULL)
    str[0] = 0;
  return dopr(str, count, fmt, args);
}

int snprintf (char *str, size_t count, const char *fmt,...)
{
  va_list ap;
  int total;
    
  va_start(ap, fmt);
  total = vsnprintf(str, count, fmt, ap);
  va_end(ap);
  return total;
}

#ifdef TEST_SNPRINTF
#ifndef LONG_STRING
#define LONG_STRING 1024
#endif
int main (void)
{
  char buf1[LONG_STRING];
  char buf2[LONG_STRING];
  char *fp_fmt[] = {
    "%-1.5f",
    "%1.5f",
    "%123.9f",
    "%10.5f",
    "% 10.5f",
    "%+22.9f",
    "%+4.9f",
    "%01.3f",
    "%4f",
    "%3.1f",
    "%3.2f",
    "%.0f",
    "%.1f",
    NULL
  };
  double fp_nums[] = { -1.5, 134.21, 91340.2, 341.1234, 0203.9, 0.96, 0.996, 
    0.9996, 1.996, 4.136, 0};
  char *int_fmt[] = {
    "%-1.5d",
    "%1.5d",
    "%123.9d",
    "%5.5d",
    "%10.5d",
    "% 10.5d",
    "%+22.33d",
    "%01.3d",
    "%4d",
    NULL
  };
  long int_nums[] = { -1, 134, 91340, 341, 0203, 0};
  int x, y;
  int fail = 0;
  int num = 0;

  printf ("Testing snprintf format codes against system sprintf...\n");

  for (x = 0; fp_fmt[x] != NULL ; x++)
    for (y = 0; fp_nums[y] != 0 ; y++)
    {
      snprintf (buf1, sizeof (buf1), fp_fmt[x], fp_nums[y]);
      sprintf (buf2, fp_fmt[x], fp_nums[y]);
      if (strcmp (buf1, buf2))
      {
	printf("snprintf doesn't match Format: %s\n\tsnprintf = %s\n\tsprintf  = %s\n", 
	    fp_fmt[x], buf1, buf2);
	fail++;
      }
      num++;
    }

  for (x = 0; int_fmt[x] != NULL ; x++)
    for (y = 0; int_nums[y] != 0 ; y++)
    {
      snprintf (buf1, sizeof (buf1), int_fmt[x], int_nums[y]);
      sprintf (buf2, int_fmt[x], int_nums[y]);
      if (strcmp (buf1, buf2))
      {
	printf("snprintf doesn't match Format: %s\n\tsnprintf = %s\n\tsprintf  = %s\n", 
	    int_fmt[x], buf1, buf2);
	fail++;
      }
      num++;
    }
  printf ("%d tests failed out of %d.\n", fail, num);
  return 0;
}
#endif /* TEST_SNPRINTF */
