FIY: sprintf function in Nios2 libsmallc.a library returns wrong value

[Altera_Forum]

Just submitted the bug report below as Service Request. 

From past experience I expect that the bug will not be fixed in 2012 and, probably, never. So be warned.   ----------------  Description: sprintf function supplied with small version of Newlib library for Nios2 (libsmallc.a) returns wrong value. It happens for majority of format specifiers (I checked %c, %d and %u) when they are used without width and/or precision sub-specifiers. It is possible that the problem exists not just in sprintf, but in other functions of printf family as well, I didn't test it, because I rarely care for return value of other functions.  Software versions: all versions of nios2eds suite that come with small library. I am sure that bug exists in versions as early as v.6.1 and as late as 11.1sp2.  Steps to reproduce: 1. Create Altera HAL based based bsp with small C library 2. Create minimalistic "Hello, world" style application with main module like that: //----------- main.c# include <stdio.h>  int main(void) {  char buf[20];  int llc = sprintf(buf, "%c", 'x');  int lld = sprintf(buf, "%d", 100);  printf("llc=%d, should be 1. lld=%d, should be 3.\n", llc, lld);   for (;;);  return 0; } //----------- end of main.c  3. Compile, link and run the application on your favorite Nios2 hardware. See the printout. My printout looks like that: llc=-1, should be 1. lld=1, should be 3.   Investigation and suggested solution: I traced the bug back to function _vfprintf_r that is implemented in module ./nios2eds/bin/nios2-gnutools/src/newlib/newlib/libc/stdio/vfprintf1.c starting from line 245. Specifically, the macro PRINT_REP is wrong. Instead of ------# define PRINT_REP(c, len)  do {   if (print_repeat (data, fp, (c), (len)))   goto error;   write_count += len;  } while (0) ---- it should be written as: ----------# define PRINT_REP(c, len)  do {  if (len > 0) {   if (print_repeat (data, fp, (c), (len)))   goto error;   write_count += len;  }  } while (0) ----------  It looks like your developer picked code out of old version of BSD library from 22 years ago and didn't pay attention to a fix submitted couple of years later.