Commit 68701e51 authored by Jay Satiro's avatar Jay Satiro Committed by Daniel Stenberg
Browse files

mprintf: Fix processing of width and prec args 

Prior to this change a width arg could be erroneously output, and also
width and precision args could not be used together without crashing.

"%0*d%s", 2, 9, "foo"

Before: "092"
After: "09foo"

"%*.*s", 5, 2, "foo"

Before: crash
After: "   fo"

Test 557 is updated to verify this and more
parent 117a0ffe

lib/mprintf.c

+40 −20
Original line number Diff line number Diff line
@@ -460,22 +460,24 @@ static long dprintf_Pass1(const char *format, va_stack_t *vto, char **endpos, 
      if(flags & FLAGS_WIDTHPARAM) {

        /* we have the width specified from a parameter, so we make that

           parameter's info setup properly */

        vto[i].width = width - 1;

        i = width - 1;

        vto[i].type = FORMAT_WIDTH;

        vto[i].flags = FLAGS_NEW;

        vto[i].precision = vto[i].width = 0; /* can't use width or precision

                                                of width! */

        long k = width - 1;

        vto[i].width = k;

        vto[k].type = FORMAT_WIDTH;

        vto[k].flags = FLAGS_NEW;

        /* can't use width or precision of width! */

        vto[k].width = 0;

        vto[k].precision = 0;

      }

      if(flags & FLAGS_PRECPARAM) {

        /* we have the precision specified from a parameter, so we make that

           parameter's info setup properly */

        vto[i].precision = precision - 1;

        i = precision - 1;

        vto[i].type = FORMAT_WIDTH;

        vto[i].flags = FLAGS_NEW;

        vto[i].precision = vto[i].width = 0; /* can't use width or precision

                                                of width! */

        long k = precision - 1;

        vto[i].precision = k;

        vto[k].type = FORMAT_WIDTH;

        vto[k].flags = FLAGS_NEW;

        /* can't use width or precision of width! */

        vto[k].width = 0;

        vto[k].precision = 0;

      }

      *endpos++ = fmt + 1; /* end of this sequence */

    }
@@ -483,11 +485,15 @@ static long dprintf_Pass1(const char *format, va_stack_t *vto, char **endpos, 


  /* Read the arg list parameters into our data list */

  for(i=0; i<max_param; i++) {

    if((i + 1 < max_param) && (vto[i + 1].type == FORMAT_WIDTH)) {

    /* Width/precision arguments must be read before the main argument

       * they are attached to

       */

      vto[i + 1].data.num.as_signed = (mp_intmax_t)va_arg(arglist, int);

       they are attached to */

    if(vto[i].flags & FLAGS_WIDTHPARAM) {

      vto[vto[i].width].data.num.as_signed =

        (mp_intmax_t)va_arg(arglist, int);

    }

    if(vto[i].flags & FLAGS_PRECPARAM) {

      vto[vto[i].precision].data.num.as_signed =

        (mp_intmax_t)va_arg(arglist, int);

    }



    switch (vto[i].type) {
@@ -640,16 +646,30 @@ static int dprintf_formatf( 
    p = &vto[param];



    /* pick up the specified width */

    if(p->flags & FLAGS_WIDTHPARAM)

    if(p->flags & FLAGS_WIDTHPARAM) {

      width = (long)vto[p->width].data.num.as_signed;

      param_num++; /* since the width is extracted from a parameter, we

                      must skip that to get to the next one properly */

      if(width < 0) {

        /* "A negative field width is taken as a '-' flag followed by a

           positive field width." */

        width = -width;

        p->flags |= FLAGS_LEFT;

        p->flags &= ~FLAGS_PAD_NIL;

      }

    }

    else

      width = p->width;



    /* pick up the specified precision */

    if(p->flags & FLAGS_PRECPARAM) {

      prec = (long)vto[p->precision].data.num.as_signed;

      param_num++; /* since the precision is extraced from a parameter, we

      param_num++; /* since the precision is extracted from a parameter, we

                      must skip that to get to the next one properly */

      if(prec < 0)

        /* "A negative precision is taken as if the precision were

           omitted." */

        prec = -1;

    }

    else if(p->flags & FLAGS_PREC)

      prec = p->precision;
@@ -804,7 +824,7 @@ static int dprintf_formatf( 
        else

          len = strlen(str);



        width -= (long)len;

        width -= (len > LONG_MAX) ? LONG_MAX : (long)len;



        if(p->flags & FLAGS_ALT)

          OUTCHAR('"');

tests/data/test557

+1 −0
Original line number Diff line number Diff line
@@ -39,6 +39,7 @@ All curl_mprintf() signed int tests OK! 
All curl_mprintf() unsigned long tests OK!

All curl_mprintf() signed long tests OK!

All curl_mprintf() curl_off_t tests OK!

All curl_mprintf() strings tests OK!

</stdout>

</verify>

tests/libtest/lib557.c

+49 −0
Original line number Diff line number Diff line
@@ -1374,6 +1374,53 @@ static int test_curl_off_t_formatting(void) 
  return failed;

}



static int string_check(char *buf, const char *buf2)

{

  if(strcmp(buf, buf2)) {

    /* they shouldn't differ */

    printf("sprintf failed:\nwe '%s'\nsystem: '%s'\n",

           buf, buf2);

    return 1;

  }

  return 0;

}



/*

 * The output strings in this test need to have been verified with a system

 * sprintf() before used here.

 */

static int test_string_formatting(void)

{

  int errors = 0;

  char buf[256];

  curl_msnprintf(buf, sizeof(buf), "%0*d%s", 2, 9, "foo");

  errors += string_check(buf, "09foo");



  curl_msnprintf(buf, sizeof(buf), "%*.*s", 5, 2, "foo");

  errors += string_check(buf, "   fo");



  curl_msnprintf(buf, sizeof(buf), "%*.*s", 2, 5, "foo");

  errors += string_check(buf, "foo");



  curl_msnprintf(buf, sizeof(buf), "%*.*s", 0, 10, "foo");

  errors += string_check(buf, "foo");



  curl_msnprintf(buf, sizeof(buf), "%-10s", "foo");

  errors += string_check(buf, "foo       ");



  curl_msnprintf(buf, sizeof(buf), "%10s", "foo");

  errors += string_check(buf, "       foo");



  curl_msnprintf(buf, sizeof(buf), "%*.*s", -10, -10, "foo");

  errors += string_check(buf, "foo       ");



  if(!errors)

    printf("All curl_mprintf() strings tests OK!\n");

  else

    printf("Some curl_mprintf() string tests Failed!\n");



  return errors;

}



int test(char *URL)

{
@@ -1394,6 +1441,8 @@ int test(char *URL) 


  errors += test_curl_off_t_formatting();



  errors += test_string_formatting();



  if(errors)

    return TEST_ERR_MAJOR_BAD;

  else