https://gcc.gnu.org/bugzilla/show_bug.cgi?id=110574
--- Comment #3 from Jonathan Wakely <redi at gcc dot gnu.org> ---
(In reply to Jonathan Wakely from comment #0)
> Using --enable-cstdio=stdio_pure on x86_64-pc-linux-gnu results in test
> failures:
>
> FAIL: 27_io/basic_filebuf/imbue/char/13171-2.cc execution test
> FAIL: 27_io/basic_filebuf/seekoff/12790-3.cc execution test
> FAIL: 27_io/basic_filebuf/seekoff/45628-2.cc execution test
> FAIL: 27_io/basic_filebuf/seekoff/char/1-in.cc execution test
> FAIL: 27_io/basic_filebuf/seekoff/char/1-io.cc execution test
> FAIL: 27_io/basic_filebuf/seekoff/char/1-out.cc execution test
> FAIL: 27_io/basic_filebuf/seekoff/char/2-in.cc execution test
> FAIL: 27_io/basic_filebuf/seekoff/char/2-io.cc execution test
> FAIL: 27_io/basic_filebuf/seekoff/char/2-out.cc execution test
> FAIL: 27_io/basic_filebuf/seekoff/char/26777.cc execution test
> FAIL: 27_io/basic_filebuf/seekoff/char/4.cc execution test
> FAIL: 27_io/basic_filebuf/seekoff/wchar_t/4.cc execution test
> FAIL: 27_io/basic_filebuf/seekpos/12790-2.cc execution test
> FAIL: 27_io/basic_filebuf/seekpos/12790-3.cc execution test
> FAIL: 27_io/basic_filebuf/seekpos/char/1-in.cc execution test
> FAIL: 27_io/basic_filebuf/seekpos/char/1-io.cc execution test
> FAIL: 27_io/basic_filebuf/seekpos/char/1-out.cc execution test
> FAIL: 27_io/basic_filebuf/seekpos/char/2-in.cc execution test
> FAIL: 27_io/basic_filebuf/seekpos/char/2-io.cc execution test
> FAIL: 27_io/basic_filebuf/seekpos/char/2-out.cc execution test
> FAIL: 27_io/basic_filebuf/seekpos/wchar_t/9874.cc execution test
> FAIL: 27_io/basic_filebuf/seekpos/wchar_t/9875_seekpos.cc execution test
> FAIL: 27_io/basic_filebuf/sgetn/char/2-in.cc execution test
> FAIL: 27_io/basic_filebuf/sgetn/char/2-io.cc execution test
> FAIL: 27_io/basic_filebuf/sputbackc/char/1-io.cc execution test
> FAIL: 27_io/basic_filebuf/sputbackc/char/2-io.cc execution test
> FAIL: 27_io/basic_filebuf/sungetc/char/1-io.cc execution test
> FAIL: 27_io/basic_filebuf/sungetc/char/2-io.cc execution test
> FAIL: 27_io/basic_filebuf/underflow/char/10097.cc execution test
> FAIL: 27_io/basic_filebuf/underflow/wchar_t/5.cc execution test
> FAIL: 27_io/basic_fstream/53984.cc execution test
> FAIL: 27_io/basic_istream/peek/char/6414.cc execution test
> FAIL: 27_io/basic_istream/peek/wchar_t/6414.cc execution test
> FAIL: 27_io/basic_istream/seekg/char/fstream.cc execution test
> FAIL: 27_io/basic_istream/seekg/wchar_t/fstream.cc execution test
> FAIL: 27_io/basic_istream/tellg/char/fstream.cc execution test
> FAIL: 27_io/basic_istream/tellg/wchar_t/fstream.cc execution test
> FAIL: 27_io/objects/wchar_t/12.cc execution test
>
> This seems to be because of code like:
>
> streamoff
> __basic_file<char>::seekoff(streamoff __off, ios_base::seekdir __way)
> throw ()
> {
> #ifdef _GLIBCXX_USE_LFS
> return lseek64(this->fd(), __off, __way);
> #else
> if (__off > numeric_limits<off_t>::max()
> || __off < numeric_limits<off_t>::min())
> return -1L;
> #ifdef _GLIBCXX_USE_STDIO_PURE
> return fseek(this->file(), __off, __way);
Oh, and fseek returns 0 or -1, not the position, so we shouldn't return its
value here.
