[Bug fortran/51418] New: Fortran format sp,f0.0 output wrong with NaN and 0.0

[john.harper at vuw dot ac.nz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51418

             Bug #: 51418
           Summary: Fortran format sp,f0.0 output wrong with NaN and 0.0
    Classification: Unclassified
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassig...@gcc.gnu.org
        ReportedBy: john.har...@vuw.ac.nz


This 6-line program prints " NaN" when IMHO it should print "NaN" and "+." when
IMHO it should print "+0." 

rimu[~]$ cat gftest.f90
character:: cnan*3 = 'NaN', fmt*13 = '(SP,A,F0.0,A)' 
real xnan
read(cnan,*) xnan
print fmt, '"',xnan,'"'
print fmt, '"',0.0 ,'"'
end
rimu[~]$ gfortran  -v
Using built-in specs.
Target: i386-redhat-linux6E
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla
--enable-bootstrap --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --disable-gnu-unique-object
--enable-languages=c,c++,fortran --disable-libgcj
--with-mpfr=/builddir/build/BUILD/gcc-4.4.4-20100726/obj-i386-redhat-linux6E/mpfr-install/
--with-ppl=/builddir/build/BUILD/gcc-4.4.4-20100726/obj-i386-redhat-linux6E/ppl-install
--with-cloog=/builddir/build/BUILD/gcc-4.4.4-20100726/obj-i386-redhat-linux6E/cloog-install
--with-tune=generic --with-arch=i586 --build=i386-redhat-linux6E
Thread model: posix
gcc version 4.4.4 20100726 (Red Hat 4.4.4-13) (GCC) 
rimu[~]$ gfortran gftest.f90
rimu[~]$ ./a.out
" NaN"
"+."
rimu[~]$ 

The output is the same on another machine:

regent[~/Jfh] % gfortran -v
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.4.3-4ubuntu5'
--with-bugurl=file:///usr/share/doc/gcc-4.4/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--enable-multiarch --enable-linker-build-id --with-system-zlib
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--with-gxx-include-dir=/usr/include/c++/4.4 --program-suffix=-4.4 --enable-nls
--enable-clocale=gnu --enable-libstdcxx-debug --enable-plugin --enable-objc-gc
--disable-werror --with-arch-32=i486 --with-tune=generic
--enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu                                                       
Thread model: posix                                                             
gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5)