Portability problems fixed by Gnulib:
@itemize
@item
+On some platforms, this function fails to set the file position of a
+seekable input stream to the byte after the last one actually read:
+glibc 2.13, FreeBSD.
+@item
On Windows platforms (excluding Cygwin), @code{socket} and @code{accept}
followed by @code{fdopen} do not return streams that can be closed by
@code{fclose}.