Xref: news2.mv.net comp.os.msdos.djgpp:7053
From: rhawes AT dma DOT org (Richard L. Hawes)
Newsgroups: comp.os.msdos.djgpp
Subject: bug fix for libc in version 2 of djgpp
Date: 11 Aug 1996 03:12:13 GMT
Organization: Dayton Microcomputer Association; Dayton OH
Lines: 76
Distribution: oh
Message-ID: <4ujj2d$s1@sally.dma.org>
NNTP-Posting-Host: dmapub.dma.org
Summary: sscanf sometimes returns incorrect values, patch fix included.
Keywords: sscanf bugs patch libc
To: djgpp AT delorie DOT com
DJ-Gateway: from newsgroup comp.os.msdos.djgpp

By Richard L. Hawes  		rhawes AT dma DOT org

	Sometime sscanf	will return the	incorrect value.  For example,
run the	following program with the first argument as "5" and it	will 
return -1 (EOF) when it should	return 1:

	-	-	-	-	-	-	-	-
#include<stdio.h>

int main(int argc, char	*argv[])
{
int i,j;

i=j=0;
printf(" %d \n", sscanf(argv[1], "%d-%d", &i, &j));
printf(" %d-%d\n", i, j);
}
	-	-	-	-	-	-	-	-

	At the end of this file	is a patch for it.  Place this file in
your djgpp directory (after you	unzip the library source code first of
coarse). Then type in the following lines at the dos prompt to fix it:

>patch <thisfile
>gcc -c	src\libc\ansi\stdio\doscan.c
>ar r lib\liba	src\libc\ansi\stdio\docan.o

Patch will ignore this note.

*** src\libc\ansi\stdio/doscan.c	Wed Jan	24 04:31:46 1996
--- doscan.c	Sun Aug	11 01:22:08 1996
***************
*** 57,61 ****
    for	(;;) switch (ch	= *fmt++) {
    case '\0':
!     return (nmatch);
    case '%':
      if ((ch =	*fmt++)	== '%')
--- 57,61 ----
    for	(;;) switch (ch	= *fmt++) {
    case '\0':
!     return (nmatch? nmatch: -1);
    case '%':
      if ((ch =	*fmt++)	== '%')
***************
*** 100,104 ****
      }
      if (ch ==	'\0')
!	return(-1);
      if (_innum(ptr, ch, len, size, iop, scan_getc, scan_ungetc,
	       &fileended) && ptr)
--- 100,104 ----
      }
      if (ch ==	'\0')
!	return(nmatch? nmatch: -1);
      if (_innum(ptr, ch, len, size, iop, scan_getc, scan_ungetc,
	       &fileended) && ptr)
***************
*** 130,137 ****
      if (ch1 != ch) {
	if (ch1==EOF)
!	return(-1);
	scan_ungetc(ch1, iop);
	nchars--;
!	return(nmatch);
      }
    }
--- 130,137 ----
      if (ch1 != ch) {
	if (ch1==EOF)
!	return(nmatch? nmatch: -1);
	scan_ungetc(ch1, iop);
	nchars--;
!	return(nmatch? nmatch: -1);
      }
    }