Calling scanf with errno set to EINTR produces wrong results in glibc-2.3.2

[Knut . Beneke]

Description:
============
Calling scanf with errno set to EINTR produces wrong results in glibc 
2.3.2.

Source of test program:
=======================
--- begin ---
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <unistd.h>
#include <time.h>
#include <assert.h>
#include <errno.h>
  
/*********************************************************************/

int main(int argc, char* argv[])
{
  printf("setting errno to EINTR\n");
  errno = EINTR;

  printf("checking sscanf\n");
  {
    char str[] = "7-11";
    int i, j, n; 
 
    i = j = n = 0;
    sscanf(str, " %i - %i %n", &i, &j, &n);
    printf("found %i-%i (length=%i)\n", i, j, n);
    assert(i==7);
    assert(j==11);
    assert(n==4);
  }
 
  return(0);
}
---end ---

How-To-Reproduce:
=================
Compile glibc-2.3.2
Compile test.c with:
gcc -c test.c -I <glibc-2.3.2-install-path>/include
gcc -o test -nodefaultlibs -static test.o 
<glibc-2.3.2-install-path>/lib/libc.a 
usr/lib/gcc-lib/i586-mandrake-linux-gnu/3.2/libgcc.a
If glibc-2.3.2 is installed use:
gcc -o test test.c
Running ./test will now cause an assertion (assert(n==4) at the end of 
test.c).
The output looks like this:
---begin ---
setting errno to EINTR
checking sscanf
found 7-11 (length=0)
test: test.c:27: main: Assertion `n==4' failed.
Aborted (core dumped)  
---end ---
In older glibc versions (tested: 2.2.4) scanf assigns n the correct value 
of 4.

Patch:
======
---begin ---
--- glibc-2.3.2/stdio-common/vfscanf.c.original Mon Nov 17 08:53:57 2003
+++ glibc-2.3.2/stdio-common/vfscanf.c  Mon Nov 17 08:54:20 2003
@@ -340,6 +340,9 @@
       wp[wpsize++] = (Ch);  \
     }  \
   while (0)
+
+  /* Reset errno */
+  errno = 0;

 #ifdef __va_copy
   __va_copy (arg, argptr);
---end ---


Best regards,
Knut Beneke