[ben -AT- 666 -PERIOD- com: Scanf bug]

[Jeff Johnston]

I just posted a fix to the current sources.

2004-10-04  Jeff Johnston  <jjohnstn@redhat.com>

         * libc/stdio/vfscanf.c (__svfscanf_r): For int conversions,
         count skipped zero characters as part of the nread count for %n.
         * libc/machine/powerpc/vfscanf.c: Ditto.

-- Jeff J.

Christopher Faylor wrote:
> Just reported in the cygwin list...
> 
> cgf
> 
> ----- Forwarded message from Ben Wing <ben -AT- 666 -PERIOD- com> -----
> 
> Somehow or other, sscanf() has gotten messed up in recent Cygwin
> installations.
> 
> Test program, with output:
> 
> /xemacs/test 2391% cat testscanf.c
> int
> main (int argc, char **argv)
> {
>   int ret, cp1, cp2, endcount;
>   char *p = "0x7d   0x000E  ";
>   ret = sscanf (p, "%i %i%n", &cp1, &cp2, &endcount);
>   printf ("ret: %d cp1: %d cp2: %d endcount: %d\n", ret, cp1, cp2,
> endcount);
>   printf ("%d\n", endcount + strspn (p + endcount, " \t\n\r\f"));
>   return 0;
> }
> /xemacs/test 2392% gcc --verbose testscanf.c
> Reading specs from /usr/lib/gcc-lib/i686-pc-cygwin/3.3.3/specs
> Configured with: /gcc/gcc-3.3.3-3/configure --verbose --prefix=/usr
> --exec-prefi
> x=/usr --sysconfdir=/etc --libdir=/usr/lib --libexecdir=/usr/lib
> --mandir=/usr/s
> hare/man --infodir=/usr/share/info
> --enable-languages=c,ada,c++,d,f77,java,objc,
> pascal --enable-nls --without-included-gettext --enable-libgcj
> --with-system-zli
> b --enable-interpreter --enable-threads=posix --enable-java-gc=boehm
> --enable-sj
> lj-exceptions --disable-version-specific-runtime-libs
> --disable-win32-registry
> Thread model: posix
> gcc version 3.3.3 (cygwin special)
>  /usr/lib/gcc-lib/i686-pc-cygwin/3.3.3/cc1.exe -quiet -v -D__GNUC__=3
> -D__GNUC_M
> INOR__=3 -D__GNUC_PATCHLEVEL__=3 -D__CYGWIN32__ -D__CYGWIN__ -Dunix
> -D__unix__ -
> D__unix -idirafter
> /usr/lib/gcc-lib/i686-pc-cygwin/3.3.3/../../../../include/w32
> api -idirafter
> /usr/lib/gcc-lib/i686-pc-cygwin/3.3.3/../../../../i686-pc-cygwin/
> lib/../../include/w32api testscanf.c -quiet -dumpbase testscanf.c -auxbase
> tests
> canf -version -o /DOCUME~1/BENWIN~1/LOCALS~1/Temp/cco65aDq.s
> GNU C version 3.3.3 (cygwin special) (i686-pc-cygwin)
>         compiled by GNU C version 3.3.3 (cygwin special).
> GGC heuristics: --param ggc-min-expand=82 --param ggc-min-heapsize=98244
> ignoring nonexistent directory "/usr/i686-pc-cygwin/include"
> ignoring duplicate directory "/usr/i686-pc-cygwin/lib/../../include/w32api"
> #include "..." search starts here:
> #include <...> search starts here:
>  /usr/local/include
>  /usr/lib/gcc-lib/i686-pc-cygwin/3.3.3/include
>  /usr/include
>  /usr/include/w32api
> End of search list.
>  /usr/lib/gcc-lib/i686-pc-cygwin/3.3.3/../../../../i686-pc-cygwin/bin/as.exe
> --t
> raditional-format -o /DOCUME~1/BENWIN~1/LOCALS~1/Temp/ccSaWKvo.o
> /DOCUME~1/BENWI
> N~1/LOCALS~1/Temp/cco65aDq.s
>  /usr/lib/gcc-lib/i686-pc-cygwin/3.3.3/collect2.exe -Bdynamic
> --dll-search-prefi
> x=cyg /usr/lib/gcc-lib/i686-pc-cygwin/3.3.3/../../../crt0.o
> /usr/lib/gcc-lib/i68
> 6-pc-cygwin/3.3.3/crtbegin.o -L/usr/lib/gcc-lib/i686-pc-cygwin/3.3.3
> -L/usr/lib/
> gcc-lib/i686-pc-cygwin/3.3.3/../../..
> /DOCUME~1/BENWIN~1/LOCALS~1/Temp/ccSaWKvo.
> o -lgcc -lcygwin -luser32 -lkernel32 -ladvapi32 -lshell32 -lgcc
> /usr/lib/gcc-lib
> /i686-pc-cygwin/3.3.3/crtend.o
> /xemacs/test 2393% a
> ret: 2 cp1: 125 cp2: 14 endcount: 11
> 11
> 
> 
> The value of endcount should be 13, not 11.  The problem is with hex numbers
> with more than one leading 0.  Change 0x000E to 0x0FFE or 0xFFFE and you get
> 13.  Change it to 0x00EE and you get 12.  In all cases cp2 is correct.
> 
> This used to work.  I know because the above code is part of XEmacs and we
> are getting lots of warnings as a result of this bug, which didn't used to
> be there, and the code hasn't changed.
> 
> 
> 
> --
> Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple
> Problem reports:       http://cygwin.com/problems.html
> Documentation:         http://cygwin.com/docs.html
> FAQ:                   http://cygwin.com/faq/
> 
> 
> ----- End forwarded message -----